# Best method of making accurate bevels.



## simonms

Hi, am hoping I can draw on some experience here, 

I want to create a gradual curve with 1" thick poplar, each slat will be around 630mm wide and 1m in length.

I am wondering what you might think would be the best method of creating the bevels. The bevels would only be about 1.2 degrees so not alot to remove but its the accurate join that I am after.

Would a jointer plane with something like the Veritas variable angle fence give accurate results? I am trying to avoid table saws as I don't have one and there are quite a few bevels to cut, any advice would be very gratefully received.

Cheers.


----------



## thetyreman

1.2 degrees is an extremely fine tolerance for woodworking, why do you need that level of precision?


----------



## simonms

It's just the angle that come from my cad drawings, maybe in reality 1 degree would be fine.


----------



## Freddyjersey2016

Is each slat really 630mm wide - do you mean 63mm? What are you trying to make, might help with advice.


----------



## simonms

sorry, yes, 63mm wide (long day), the curve is part of a loudspeaker design, there are 8 slats in each curve.


----------



## custard

I'm struggling to visualise this. 

Is it coopered work, ie like the way barrels are made with bevel edged staves that butt up against each other to form a curve?


----------



## simonms

precisely that.


----------



## MikeG.

If the pieces are straight (not curved), and this is a one off, I would simply plane the edge to the required angle with a hand plane. With a larger angle, this would be quite easy, because all you need do is mark a line on one face of the board, and plane the edge down to that. However, if, as you say, your board was 25mm thick then you need to plane down 0.5mm on one side to achieve 1.2 degrees, and that is quite hard to measure and mark accurately. 'twere it me, I would take the traditional coopering approach of "offering up and adjusting", by planing up 2 or 3 staves, taping them together, and checking how they sit against the curve I was trying to achieve. Too curvy?.......take a bit off the upper edge. Not curvy enough?.............take a bit off the lower edge.

I presume you aren't trying to achieve the full 360 degrees? I say this because you are aiming for something 1500 in radius (about 1504, actually, externally), which is a pretty gentle curve, or a pretty huge speaker!!


----------



## simonms

Thanks Mike, 

really appreciate your reply.

Yes, the final components are large. I understand what you describe, I think there will be some experimentation on some sacrificial pieces before I get the knack, I have had experience with a jointer plane but nothing like this sort of work so not a seasoned expert. 

Would anybody recommend something like the Veritas variable angle fence or a Stanley 386 for something like this?

Does a Festool rail saw have any place in this sort of work?


----------



## deema

This is relatively easy to do. Build a jig, which consists of two piece of wood set apart the thickness of your stuff. One piece has a fence added for the plane to run against. Plane down one of the pieces so that the plane tilts the angle you want. You now run the plane against the fence when planing each piece. The blade will initially cut in to the jig, but will leave an piece uncut on each of the supports either side of the mouth. What you will end up with is consistent bevelled stuff.

The hardest bit is making the jig. (Two pieces exactly the same width with one shimmed rather than planing is perhaps an easier route to baking the jig)


----------



## Jacob

simonms":3lyc579f said:


> ...
> Would anybody recommend something like the Veritas variable angle fence or a Stanley 386 for something like this?....


Nope. Gadgets are very tempting but there will be easier and cheaper ways such as deema's suggestion of a jig.
There's also the time honoured process of "offering up" whereby you shape the thing as best you can then make final adjustments by butting the pieces together and seeing where they do or don't fit.


----------



## Setch

If have thought the relatively small angle would be achievable with a shooting board and a plane with the iron skewed. You could use you bench and a piece of scrap as an improvised shooting board if the pieces are quite long.


----------



## custard

simonms":2v4ljceo said:


> Would anybody recommend something like the Veritas variable angle fence or a Stanley 386 for something like this?
> 
> Does a Festool rail saw have any place in this sort of work?





Here's the Stanley 386 I often use for this kind of work,







It works pretty well, although the depth of the tool/fence means there's a minimum width for components. You say your components are 63mm wide, plus you'll need say another 12mm to secure in a vice, meaning you'll need a fence that's no bigger than 51mm. Unfortunately the 386 fence is 64mm, which rules it out unless you used double stick tape to attach a narrower sub fence.

However, there are plenty of similar tools and, if well made, they'll all deliver accurate and consistent results. For example I usually knock up a little MDF template for setting tool angles, in this case I'd make one at 91.2 degrees, and I'd be confident of working to that tenth of a degree.

Regarding a Festool plunge saw on a track, you can set any decent brand plunge saw to accurate angles, but the finish won't be as good as with a hand plane, plus it's really tricky ripping a 63mm wide component with a rail balanced on top.

If you've got serious quantities then ripping on a table saw with a freshly sharpened, finely set blade is probably your best bet. But for more modest quantities (especially if you're not confident about accurate ripping on a table saw) then I'd find a plane with an angled fence. That's basically why I keep the 386. I've a professional workshop with plenty of machinery, but it's surprising how quick the 386 can be, plus the quality of the planed finish is absolutely flawless and so delivers impeccable glue lines.

Good luck!


----------



## simonms

Thankyou all very much especially Custard, cheers!

1-2degrees is such a small amount that I was wondering if the rail saw might manage that without to many accuracy issues, it's just a whisker, make one initial pass leaving 1mm and then do the rest with a 2nd pass and clean up with the plane, poplar seems quite a soft hardwood if you get my drift. Off course I would have to pop another piece of 1" timber uner the rail guide and be careful in being sure its both safe and level

Yes I may have to customize a fence maybe (although I have not check the Veritas yet) but I have a hunch that I would feel more comfortble working with a jointer plane and the fence.


----------



## rbland

I visited an Axminster store today and bought one of these Veritas edge trimming planes:

https://www.axminster.co.uk/veritas-edg ... e-ax724910

You can attach wedges to the inner side to angle the fence to make accurate bevels (although it’s a small plane so you’d have to straighten the edge with a jointer first).


----------



## simonms

Thanks rbland,

I have just ordered one to try out, the poplar planks will come in planed on all sides so hopefully the faces will be pretty square for starters.


----------



## custard

simonms":334ttvze said:


> the poplar planks will come in planed on all sides so hopefully the faces will be pretty square for starters.



Unfortunately "Planed All Round" isn't the same thing as planed straight and true all round. You might get lucky or you might not, it's just the luck of the draw I'm afraid.

I'd always advise any aspiring woodworker to buy rough sawn timber and learn how to dimension and square the timber themselves. There's really no viable way of sourcing accurately dimensioned timber. Even in the (unlikely) event that your boards left the timber yard straight and true, as soon as there's a change in moisture they'll start to misbehave again!


----------



## simonms

Ok so if I am aiming for 1" thick walls on the curve so what would you say would be optimal for having the timber supplier dimension them to once factoring in flattening? I will try and upload a drawing of my curve so you can see what I am trying to do as this will also have a bearing on the start point thickness of material.

Just been looking at shooting planes, essentially a board could be slightly tilted (was thinking a strip of 1mm or so ally under the back edge) to achieve the desired bevel but is it the norm to be doing this with 1m long passes?


----------



## custard

simonms":2w968dsz said:


> Ok so if I am aiming for 1" thick walls on the curve so what would you say would be optimal for having the timber supplier dimension them to once factoring in flattening?
> 
> _For a finished 25mm I'd ideally get 30mm or 1 1/4" rough sawn boards. You may or may not be able to source this thickness, so I'd also want to explore the viability of a finished 18-20mm from the much more common 25mm or 1" boards._
> 
> Just been looking at shooting planes, essentially a board could be slightly tilted (was thinking a strip of 1mm or so ally under the back edge) to achieve the desired bevel but is it the norm to be doing this with 1m long passes?
> 
> _Nice idea, one problem with using a shooting board to produce bevels is setting the planes lateral adjustment to precisely the angle you want. This isn't insurmountable but will need a bit of head scratching, get this right and there'd be no need to shim the workpiece. The other thing is you'll need some temporary stops on the shooting board to set the component width, again this is perfectly do-able. I use a slightly different style of shooting board, one that runs along the bench rather than across it. This style would be ideal for your purposes, here's mine for reference,_
> 
> 
> 
> 
> 
> _I don't know where you're based, but if you ever find yourself in South Hampshire at the Western end of the Solent, then just bring your rough sawn boards to the workshop and I'll machine them to square all round while you wait._


----------



## simonms

Well that's kind of you but you might live to regret that offer, I'm in Brighton...pm on the way.


----------



## simonms

I am thinking of experimenting with a long shooting board, the picture gives a general idea, any thoughts on this approach?


----------



## MikeG.

simonms":9rvke60p said:


> I am thinking of experimenting with a long shooting board, the picture gives a general idea, any thoughts on this approach?



That can't work. The principle of a shooting board is that the plane runs along a piece of wood as a guide, most of which it planes away to the depth of the blade protrusion. Unfortunately, you've put a piano hinge on the critical bearing surface/ edge.

 Alluvium is loose sedimentary deposits. It's a geographical/ geological term, not a workshop term.


----------



## simonms

Yes I see what you mean, am new to shooting boards so sorry for the glaring error.

Any ideas on proper implementation? I received this advice but struggling to picture it,

I would be looking more at a shooting board where you can change the angle the board is held at. Think of a door held to a door frame with two hinges, lay the door frame on your bench and the plane runs along this piece of wood on its side so the blade presents itself to the wood slat that you clamp to the door which can tilt to any angle. All you have to do is change the angle of the door to suit the angle on your slat. There are electronic gadgets these days that measure angles, even some phones can do it, or use a sliding bevel. This would work for long and short slats and would be very accurate, as the wood is held securely and all you have to do is run the plane on its side along the frame.


----------



## simonms

Maybe this? (sediments removed).


----------



## Jacob

Just tilt the blade in the plane?


----------



## custard

Jacob":1qeuosv4 said:


> Just tilt the blade in the plane?



Yes, that's what I'd do. Make a little angle setting reference piece out of 6mm MDF, use run/rise to set the angle and you can hit a tenth of a degree. Then use that in conjunction with the lateral lever on the plane to set the required angle.

You just need to make sure you've honed your plane blade so the cutting edge is dead straight.


----------



## simonms

It's a great idea but as the curve tightens I have worked out I will need up to 6-7 degree bevels hence the shooting board idea. So essentially need to be beveling between 1 and 6 degrees.

Thanks for the input so far, much appreciated.


----------



## MikeG.

simonms":2jfzki61 said:


> It's a great idea but as the curve tightens I have worked out I will need up to 6-7 degree bevels hence the shooting board idea. So essentially need to be beveling between 1 and 6 degrees..........



Hang on.......are you saying that the curve is variable? It isn't a continuous radius? In which case, why the need for accuracy?


----------



## simonms

Sorry Mike, not understanding this, surely any curve would require accurate bevels for it to adopt it desired form. Do you mean that you could essentially be off with the first bevel and adjust for the following?


----------



## MikeG.

You have the advantage of knowing what it is you are trying to achieve. We're just guessing. If we had a drawing, and the question was "how do I build this?", then all the guessing would be done with, and you'd be getting some useful opinions and ideas. Certainly coopering was "offer up and adjust", rather than some mechanical pursuit of angular perfection.


----------



## simonms

Ok I see. sorry Mike, I hope these drawings shed some light on it, one is a cross section and the other a 3d wireframe.


----------



## simonms

The cross section.


----------



## St.J

Does this need to be seamless?
I wonder if bead and cove, as used is thousands of strip planked canoes and kayaks, might be a way to go?
Are you building it round a form?


----------



## simonms

Yes, annoyingly it does need to be seamless hence the need for nice tight joins, certainly a jig will be made once I have forged an idea of the best approach, I like the idea of an adjustable shooting board so any thought on implementation would be gratefully received or indeed suggestions why it might not be optimal or other ideas. 

I am still wondering, due to the small bevels whether the rail saw might work ok, maybe have to tidy up with a plane afterwards.


----------



## Jacob

Now can see what it's supposed to be like!
I'd suggest doubling up your 63mm or more to make wider boards, planing it over thickness, jointing as best you can over a former (place one piece on, adjust edge of next piece to fit), glue, then shape the inside and outside surfaces with planes, nicely cambered for inside curves, and/or scrapers etc.
i.e. a woodworker's approach, not a machinist's or engineer's. Join it first then finish shaping it, rather than vice versa.


----------



## MikeG.

Those curves are so shallow they're in danger of it looking like a flat board gone wrong.

What's the imperative for the curve being right, exactly as drawn? I mean, what if you were to make the bevels first, do the coopering, and glue that lot together, then shape the other pieces (top, bottom, whatever) to suit?


----------



## simonms

Thanks guys, well without going into the subject of exponential horn flares all I can offer is the the curve has to be constructed with this exact amount of staves and be as close to the drawings as I can possibly make them.

What I am after is the best method of accurately cutting these bevels. I would be happy to experiment with my own ideas on how this might be done but thought it a good idea to ask the experts. My habit with woodwork is I achieve good results but always take the long way round so I am trying a different approach and asking for help.

My intention is to make the all of bevels and check they adopt tight joins over a jig, glue up then shape them.


----------



## MikeG.

I don't understand why you don't engage with the suggestions. But, as you don't, you can carry on without my input.


----------



## simonms

Right, moving on, it might be an idea for me to explain that I am copying a pre existing design, the drawings demonstrate the conclusion of my back engineering process. I am sure many other and possibly better ways of constructing this curve might be possible and the suggestions have all been very welcome and interesting but I am hemmed in.


----------



## Jacob

You do realise that each bevel is theoretically going to be different due to the free shape of the curve - varying by tiny fractions of a degree?
The idea that you could cut each of these perfectly and then fit them together is a non starter.
Are you looking at an original item to copy? If so I suggest looking a bit closer - your "reverse engineering" looks more like a wild and incorrect guess as to how it was, or could be, made.
What you could do is plane all the bevels to the same angle in such a way that they'd close the gap on the front but remain open to varying degrees on the back.
One very traditional and simple way to make up a curved surface is to kerf the back of the piece and then bend it around a former. Commonly seen on the bull nose bottom step of a stair riser - may turn through 180º in quite a tight radius.
In your case you could make up the board flat (easy) then kerf the back to a few mm from the front with as many kerfs as you need, then bend it to fit a former.


----------



## Beau

If it is part of a horn on a speaker would one side be invisible? Just wondering if you could kerf some veneered board to the curve. 

I am guessing this curve will be joined to some sides on the ends. The snag I see is you are building a wide board in solid wood that is going to want to expand and shrink. You will need to devise a way to allow it to do this if my guess is accurate.


----------



## simonms

Jacob and Beau, thanks for your insights, very helpful.

Jacob, unfortunately my drawings are not wildly inaccurate guess work, they are precise transcriptions to the actual object itself. I do realize that the bevels are all differing by tiny amounts from stave to stave. All I am assuming is that it was planed to fit, but I could be wrong on the actual process as I have no way of knowing, just pure guess work.

I have made this curve by laminating ply over a former in a vacuum bag but this is not the tradition method and that is what I want to attempt to build.

Beau, thanks and certainly movement is going to be a consideration, the poplar wood I have been quoted for is quarter sawn and kiln dried so was hoping that might get me off on the right foot but am painfully aware that this will still mean that things will move but my experience here is non existent being the first time I have considered making something like this. As I have said I am hemmed in with my methods of construction and it's clear kerfs was not used.


----------



## Jacob

simonms":i1kdqg69 said:


> Jacob and Beau, thanks for your insights, very helpful.
> 
> Jacob, unfortunately my drawings are not wildly inaccurate guess work, they are precise transcriptions to the actual object itself. I do realize that the bevels are all differing by tiny amounts from stave to stave. All I am assuming is that it was planed to fit, but I could be wrong on the actual process as I have no way of knowing, just pure guess work.


OK planed to fit, but not by setting up a machine or a hand plane to precisely cut each piece with its fine variation in such a way that they would all go together like a jig saw. Have you looked at both faces of the original? The back would give a clue. Have you any photos?
My guesses are either:
most likely they would all be undercut by the same amount such that the top face would show a tight fit but the back would be less tight - but barely noticeable as the angle is very small and full of glue. Clamped tight.
Or they were planed at 90º and clamped even tighter.
Or planed at 90º but each piece eased to fit as it was dropped on to the former. Each piece would then have one edge at 90º but the meeting edge slightly eased to fit at the angle. Your "precise transcriptions" would not have found this unless you had done some very fine lab work on a demolished original.
Whichever method the material would start over sized in thickness but brought down smooth after the glue had gone hard.


----------



## simonms

I don't have any photos to hand but my process was to measure the width of the front and back face and draw in the bevels so the drawings are a good reference I believe, there is no way to actually see the cross sectional cut lines as the sides are covered. The only datum I had was the start angle which was measurable then just adding on the distances as they came from the from top and bottom. It's the most accurate process as I could manage given what I had to go on. From what you are saying this drawing is showing that constructing this would be a non starter so am struggling to figure out whats going on here.


----------



## worn thumbs

I'm a bit surprised this thread has gone on so long.How do you suppose the fellows who built this Dragon managed to get tight seams?


----------



## simonms

Jacob, thanks for you insights, I completely agree with your assessment, I would never have been able to tell if we were looking at 90 degree bevels or 91 degree bevels but thats all I had to work with. What you have suggested may well be true and is a great insight and just what I am looking for, your experience is something that I have not got so thanks again.

I m likely making the mistake of looking at cad drawings and not the reality of building. Could we consider that one face might be at 90 and the next or adjoining slat might have been carefully planed to butt up against it. Working from the cabinet not the drawing so to speak, I think this might certainly be a case of choosing my best approach from all of your help and just seeing how that works in reality. Poplar doesn't seem too expensive a material so that is a plus.

Any thoughts on movement and best methods to combat this would also be interesting.


----------



## MikeG.

worn thumbs":25migb7i said:


> ....How do you suppose the fellows who built this Dragon managed to get tight seams?.......



Beautiful.

By offering up and adjusting. That option has been dismissed (by being repeatedly ignored). Again, we've spent more time prattling about this than it would have taken to do the job, by a factor of about 10. The thing I'm waiting for is to hear that it's going to be a painted finish, as indicated by the choice of poplar, rendering the entire conversation pointless.


----------



## Jacob

worn thumbs":357y5pym said:


> I'm a bit surprised this thread has gone on so long.How do you suppose the fellows who built this Dragon managed to get tight seams?


Exactly!
Carvel built and then smoothed, a.k.a. "fairing in"
https://en.wikipedia.org/wiki/Carvel_(boat_building)


----------



## simonms

Cheer up Mike, I have made it clear that I am asking for advice on something that I have never done and from that perspective what might appear an obvious method to an experienced woodworker, I have to look into it and understand what it means. One might expect a slightly more lenient approach from advisors considering my lack if experience, read between the lines a little. I don't believe I have dismissed anyones suggestions, certainly there are 3 practical posts I have already acted upon regarding squaring up boards, buying a particular plane and Jacobs recent post regarding methods of joining. Now that I understand what Jacob is saying then your first posts make sense to me, if I have come across as dismissive it is certainly not intentional.

You may think this is un necessary prattle but to me it's very valuable and gratefully received advice. I certainly don't want to cause problems or continue in this manner so may I respectfully ask for constructive suggestions.


----------



## Jacob

So that's covered three very trad methods of making things look perfect: 
_under cutting_, 
_offering up_, 
finishing (plane, scraper, sanding) _after _joining.


----------



## simonms

Yes, thanks Jacob and i understand in theory what all of those methods entail so I hope in realty I might be able to get some half decent results. If it were not for the help here I would have likely used the rail saw, probably slightly undercut on every bevel on my drawing but now I think I will re draw leaving 90 degrees on one edge then plane to adjust as I go....as Mike was describing on page 1


----------



## custard

worn thumbs":2rhs5fcq said:


> I'm a bit surprised this thread has gone on so long.How do you suppose the fellows who built this Dragon managed to get tight seams



Isn't that comparing apples with pears?

Presumably the bloke building the Dragon was planking over ribs/frames, so no glue-up challenges, where as the original poster faces a quite tricky cramping and gluing job. 

Furthermore the Dragon looks like carvel construction, so it's far from gap free as it'll need the caulking hammered into the seams. 

I always think with woodworking projects there is such a thing as "appropriate viewing distances", which in turn dictates the required fit precision and quality of finish. The OP's projects and the Dragon are at different ends of that spectrum, I see plenty of fine boat varnishing every time I wander around my local marina, but what's first rate varnish work on a boat would be considered third rate on a violin. Same rules apply to fit quality.


----------



## MikeG.

custard":3550mpcx said:


> .........Furthermore the Dragon looks like carvel construction, so it's far from gap free as it'll need the caulking hammered into the seams.....



It's much more likely to be cedar strip construction, which is really a form of veneering in that the strips are only 3-5mm thick, and likely glued to a ply substrate. If not, as in canoe construction, for instance, then the same thickness cedar strips are edge joined (offer-up-and-adjust, again) over a series of temporary frames. They are then epoxied over, so whilst there is no caulking, the joins don't have to be perfect to be watertight. 

My approach to the construction that the OP has taken on would be to make a couple of formers (just cut from the flat from MDF), then offer up each piece in turn, adjusting the edges as I went. I would glue up one piece at a time (ie wait for each join to set before moving on to the next), using tape and/ or string as clamps. Depending on the finish, you could even pin the timber to the formers, temporarily, and/ or fix temporary battens to the formers and wedge from those. I wouldn't however, have taken on a project I didn't have the skills, knowledge or tools to attempt.........and I list those requisites in a descending order of priority.


----------



## Jacob

custard":bfg9310n said:


> worn thumbs":bfg9310n said:
> 
> 
> 
> I'm a bit surprised this thread has gone on so long.How do you suppose the fellows who built this Dragon managed to get tight seams
> 
> 
> 
> 
> Isn't that comparing apples with pears?
> 
> Presumably the bloke building the Dragon was planking over ribs/frames, so no glue-up challenges, where as the original poster faces a quite tricky cramping and gluing job.
> 
> Furthermore the Dragon looks like carvel construction, so it's far from gap free as it'll need the caulking hammered into the seams.
> 
> I always think with woodworking projects there is such a thing as "appropriate viewing distances", which in turn dictates the required fit precision and quality of finish. The OP's projects and the Dragon are at different ends of that spectrum, I see plenty of fine boat varnishing every time I wander around my local marina, but what's first rate varnish work on a boat would be considered third rate on a violin. Same rules apply to fit quality.
Click to expand...

Same "standard" just scaled up or down. OP would be working with small pieces on a former (in place of ribs and frames) so it'd be a lot easier than building a full size boat!


----------



## simonms

Thank you Mike! Great advice, we all have to start somewhere, believe it or not I am not a total cretin in terms of woodwork it's just that I have never done anything like this before.

I am going to adjust my drawings and post them up so that you can give the approach thumbs up or thumbs down depending on my understanding of the methods described.


----------



## MikeG.

If you do proceed along those lines, then you must be working on the 3rd piece before you glue the first join. By that I mean you must have planed up *both* edges of the second piece before you glue it in place, as you won't have access to the free edge of the piece again once its other edge is glued to the preceding piece. So you'll be needing to do a series of dry fits well ahead of the gluing.


----------



## simonms

Thanks again Mike, I will be certain to do that. The actual method to make the adjustments are still not decided but I am wondering if the shooting board idea (obviously my previous drawings on the design would have to be doctored somewhat) would be the way to go.

Maybe its just a matter of suck it and see and re evaluate if necessary.


----------



## worn thumbs

custard":24q6kwjz said:


> worn thumbs":24q6kwjz said:
> 
> 
> 
> I'm a bit surprised this thread has gone on so long.How do you suppose the fellows who built this Dragon managed to get tight seams
> 
> 
> 
> 
> Isn't that comparing apples with pears?
> 
> Presumably the bloke building the Dragon was planking over ribs/frames, so no glue-up challenges, where as the original poster faces a quite tricky cramping and gluing job.
> 
> Furthermore the Dragon looks like carvel construction, so it's far from gap free as it'll need the caulking hammered into the seams.
> 
> I always think with woodworking projects there is such a thing as "appropriate viewing distances", which in turn dictates the required fit precision and quality of finish. The OP's projects and the Dragon are at different ends of that spectrum, I see plenty of fine boat varnishing every time I wander around my local marina, but what's first rate varnish work on a boat would be considered third rate on a violin. Same rules apply to fit quality.
Click to expand...


The better Dragons,such as this Borresen ,were tight seamed.The majority of them were built years before the much cruder strip planking technique became common and as Jacob says you ought to use a former.There is also the high probability that when you don't have a former the shape will vary almost from minute to minute with moisture changes.


----------



## simonms

Mike was correct in his assumptions that the originals were painted but I am trying to avoid that if I can hence the pursuit of good bevels.


----------



## OscarG

This thread made my brain hurt...not hard!

Can you please post pics when this is finished? curious to see what this will become.


----------



## MikeG.

simonms":iz11hfbr said:


> Mike was correct in his assumptions that the originals were painted but I am trying to avoid that if I can hence the pursuit of good bevels.



In which case poplar isn't a great choice of timber. Poplar generally is for painting only, at least in better work.


----------



## simonms

Sure, it is however a good choice for sound qaulity in this particular application and also what was used originally. 

I know poplar is not known for it's alluring beauty but again, I am somewhat hemmed in regarding materials choice.


----------



## Jacob

simonms":nen7vvb6 said:


> Mike was correct in his assumptions that the originals were painted but I am trying to avoid that if I can hence the pursuit of good bevels.


Painted is utterly different. There would almost certainly have been no effort to match bevels - they all would have been square planed all round, glued over a former, gaps filled, shaped, remaining gaps filled, painted. The narrow laths would make this easier as the difference at the edges would be reduced.
If you want nice looking wood then it's a different game altogether. You wouldn't use poplar for a start (boring and dull) unless veneered instead of painted. Solid wood different again.
You really need to saw stuff and smash it to bits to find out how its made!


----------



## simonms

I could see the joins through the paint quite clearly and there didn't seem to be any signs of filling but you might well be correct. I think it might be asking a lot on the first run to get things perfect so the fall back is to paint it but I would like to try.

I have re drawn the curve to what I understand might be a good way of approaching this from all the advice given. 

So the first slat will start the curve with a 90 degree cut, the adjoining slat will have the face joining the first slat beveled but the opposite edge will again be at 90 degrees and so on. Here are some pictures, one of the complete cross section and another of a typical slat.

If I am right in my understanding the bevels would need to be carefully planed in offering up to check as you go over a former.


----------



## simonms

The curve.


----------



## OscarG

If you do end up painting it, could you not create a template of the entire curved shape then using that template with a router (on say 1 inch thick stock) make 39 identical curved sections and glue them all together to make one big curved wall that's a 1m high?


----------



## simonms

I see what you mean Oscar and did try that out of interest with plywood and locating dowels for each component, it was not 100% successful but perfectly passable. The issue I have is that I must adhere to the original methods of building but as Jacob has pointed out short of sawing an original to bits I have to do a bit of educated guess work and although the methods I am proposing with the last pictures might not be exactly as it was done in the past I think it would be fine as it's not a million miles away and I like the idea of being slightly more precise in the methodology.


----------



## Derek Cohen (Perth Oz)

I do not understand what is so difficult at jointing 89 degrees. I do it all the time when I aim for 90 !  

Seriously, create a 1 degree shim for a flat shooting board, lay the work piece on that, and joint the edge. 

Regards from Perth

Derek


----------



## woodbloke66

Derek Cohen (Perth said:


> Seriously, create a 1 degree shim for a flat shooting board, lay the work piece on that, and joint the edge.
> 
> Regards from Perth
> 
> Derek


Simples works :lol: - Rob


----------



## custard

Here's the problem with the shim on the shooting board idea. You'd still have to check that the plane's lateral lever is correctly positioned. So why not get rid of the shim entirely and simply set the 1.5 degree bevel angle using the lateral lever in the first place?


----------



## Derek Cohen (Perth Oz)

Custard, as you are aware (is this the beginning of senior moments?  ), the lateral lever is only used to square the blade. A canted blade can wreck a shooting board.

A shim should be reliable. I would use one of those digital angle gauge boxes on top of the work piece to check the angle is consistent.

Regards from Perth

Derek


----------



## Jacob

Derek Cohen (Perth said:


> ..... A canted blade can wreck a shooting board.


In that case you need to make a better shooting board. A canted blade is exceptionally useful on a shooting board or off it.


> A shim should be reliable. I would use one of those digital angle gauge boxes on top of the work piece to check the angle is consistent.
> 
> Regards from Perth
> 
> Derek


I wouldn't bother at all about consistency - if you look at the OPs drawings the angle are all going to be sightly different. I'd bother about how each piece fits against the previous one. Don't measure/gauge anything - just look at the fit. 
No need for digital gadgets when you've got eyes. :lol:


----------



## Derek Cohen (Perth Oz)

Jacob":2igbk4c6 said:


> Derek Cohen (Perth said:
> 
> 
> 
> ..... A canted blade can wreck a shooting board.
> 
> 
> 
> In that case you need to make a better shooting board. A canted blade is exceptionally useful on a shooting board or off it.
> 
> 
> 
> A shim should be reliable. I would use one of those digital angle gauge boxes on top of the work piece to check the angle is consistent.
> 
> Regards from Perth
> 
> Derek
> 
> Click to expand...
> 
> I wouldn't bother at all about consistency - if you look at the OPs drawings the angle are all going to be sightly different. I'd bother about how each piece fits against the previous one. Don't measure/gauge anything - just look at the fit.
> No need for digital gadgets when you've got eyes. :lol:
Click to expand...


Jacob, really?

The only time you want to cant a blade on a shooting board is to square it to the side of a out-of-square shooting plane. 

Consistency is everything. You can even be skewed ... as long as mating pieces are consistent with this, such as when match planing.

I do not expect perfection, but I aim for it. If you do not aim for accuracy, what do you end up with? :shock: 

Anyway, I do not believe that you mean any of this - you are deliberately being obtuse. 

Regards from Perth

Derek


----------



## simonms

Thanks for the continued discussion, much appreciated. I am just about to have a trial run at a few methods and see if I can turn my hand to this and just wanted to check how people feel about my methods shown in the drawings of leaving a 90 degree angle on one side of the piece and beveling the other and so on to create the curve. My intentions are to give this some practice and continue to post with any issues I might run into. I'll be making up my shooting board next week.


----------



## AndyT

There's a tiny issue in that the two edges won't match - the bevelled one will be slightly wider than the square one - so there will be a little step at the join. But in practice you should have enough spare thickness left in the wood for this not to matter. I'm assuming you will be planing everything to a fair curve, not leaving it as a set of flat facets.


----------



## simonms

Thanks Andy, yes, thats the idea. I was thinking that leaving the 90 degree bevels would halve the amount of work and leave some fairing but the reality of this process is an unknown to me. I am going to have to carefully consider my starting widths.


----------



## Jacob

simonms":1r68kn5w said:


> ..... Maybe after dry fitting for good joins I might remove them beforehand.


Nope. 
The whole point of "fairing in" or finishing _after _something has been put together is that errors occur during the process of joining. If you try to finish _before _you just get a different set of things to "fair in" and lose more thickness in the process.


----------



## Jacob

Derek Cohen (Perth said:


> .....The only time you want to cant a blade on a shooting board is to square it to the side of a out-of-square shooting plane.


Unless you want to undercut it as per our OP - often done anyway to get a nice tight join on the visible face. You can do it in the vice, not only on a shooting board


> ...
> Anyway, I do not believe that you mean any of this - you are deliberately being obtuse. ...


Moi? No certainly not!
Our OP won't find out how to do it until he starts and if he's lucky he will start using his eyes. If he's really unlucky he'll become bogged down with "precise methodology" , precision gadgets and be endlessly trying to square the circle.


----------



## simonms

Ok, so plane bevels as I go to fit and once I am happy with that part glue up in stages and then fair.

This will be a learning curve (boom boom) for me so I won't treat the first attempt like the final job more of a matter of seeing how this particular method works in reality then adapt it if I need to but I want to draw on experience to get off on the right foot. This thread has probably saved me a few mistakes so far.


----------



## Jacob

simonms":1ql7wc2i said:


> Ok, so plane bevels as I go to fit and once I am happy with that part glue up in stages and then fair.


Yep. Mark them as you go so they go back in the right order. Perhaps pencil numbers at one end or something.
In the old days it would have been done with hot glue so you'd fit and glue each piece one at a time, not needing cramps. Not needing very precise bevels either as glue would fill space.
Trad methods are a lot easier.


> I am going to have to carefully consider my starting widths.


Too much thinking! You already settled on 63mm why not just go for it?


----------



## simonms

Ah, I have made hot glue (rabbit skin glue if my guess is right) for priming canvas and noticed Titebond do a version, might that be a good choice? I will take your advice Jacob and not be too precious with my first run. 

Sorry I meant to say thickness, these curves will need to fair down to a 1" thickness.


----------



## custard

Derek Cohen (Perth said:


> Custard, as you are aware (is this the beginning of senior moments?  ), the lateral lever is only used to square the blade. A canted blade can wreck a shooting board.



I grant you it could be very slightly problematic if you were end grain planing. For example, I wouldn't use this shooting board for this job,






But to be honest, I rarely use that particular shooting board much anyway. And as this job is _long grain_ shooting not _end grain_, it's a completely different challenge that requires a different (and in my view better) design of shooting board.

I'd use a shooting board that runs _along_ the bench rather than _across_ the bench. That's likely to be essential for this job as these components are probably too long to even fit in an "across the bench" shooting board.

The style of along the bench shooting board I prefer has a fence which mounts via a tight friction fit spline into a groove worked on the underside of the fence. You can see the arrangement here,





Amongst the many advantages of this design is this, a quick tap and I can slide the fence back by 1/16". On long grain shooting the fence is only required as a stop rather than an anti-spelch device, so there's no loss of functionality in doing this,





But the proof of the pudding is in the eating, so here I've set the lateral lever to give the 1.5 degree bevel that this project requires. Just a couple of quick strokes and here it is worked into an off-cut,





Because this project requires multiple components all with the same bevel angle, I might be tempted to pin a couple of wooden stops to the bed of the shooting board, thereby setting the width of the components. That way it becomes a simple matter to churn out as many copies as you want, all identical and precise.

And, going back to your original point Derek, absolutely no shooting boards were hurt in the making of this W.I.P!


----------



## simonms

Fantastic post, thanks!


----------



## Jacob

custard":1p9ol81y said:


> .......
> Because this project requires multiple components all with the same bevel angle, ......


It doesn't though, if you look at the drawing every angle could be slightly different! post1263539.html#p1263539
Pretty convincing evidence that the thing was put together by hand with planed-square-all-round pieces, on a simple former, one piece at a time eased as necessary. 
With no gadgets, precision measuring kit, CAD, uber expensive tools, certainly in less time than it took the OP to do the drawings. :lol: :lol:
And probably no shooting board either - they are a bit of an obsession with modern woodworkers. Though if you did use a shooting board you'd adjust the angle the easy and obvious way by tilting the blade. No shims, no tilting boards, no nonsense!


----------



## Inspector

I know the OP said at the outset that he doesn't have a table saw. It is a tool he should consider getting if not for this project, a future one. It is what I would use for this and I probably have had it done in about 15 or 20 minutes at most. I respect those that used hand tools all the time and have a highly developed skill with them. I'm competent with hand tools but there are times when I want to get on with it. Since the wood will be sawn to width somehow it seems the easiest to cut the bevels as it gets ripped to width, even with each of the variable angles. If I understand the project there will need to be 2 to 4 of each stave to make a pair of speakers so the saw would make very quick work of the staves.

I hope the OP posts a few pictures of his project so we can see what he is making.

"Consistency is everything.*You can even be skewed* ... as long as mating pieces are consistent with this, such as when match planing."

Derek are you advocating tacking shims under the sole of one of your shoes? :wink: 

Pete


----------



## simonms

Thanks Pete,

As it stands I don't have the space for a table saw but my first thought was that that might be the quickest way of approaching it. 

For the first section of the job I would need 26 staves all beveled on one long edge and all bevels differ slightly and each of the 26 staves are just over a meter in length. I have limited experience with a table saw so I wonder whether anyone might suggest how long this job might take in there experience. 

I am always using the Festool rail saw so know my way around that but my thoughts were that it might not be accurate enough to do this job.

Again, thanks for the continued discussion and off course I will post some pictures as I go, just waiting for a few more quotes on the timber.


----------



## MikeG.

Have you made your formers yet Simon?


----------



## simonms

Not yet Mike, I have them all drawn up for CNC'ing but what I was planning was to get the poplar and have some practice with my plane and see if I can master it and suss out which method suits me best. If I think I might be able to do it then I would order up the jig for the first curve , sort of take it step by step.


----------



## MikeG.

CNC? Really? Honestly, that's 10 minutes work with basic tools. And you will make the entire curve in one, won't you. I don't see how you'll know whether your planing is good enough unless you've got the former on which to lay the pieces.


----------



## simonms

I have a friend with a CNC router so work will be free and I was just wanting to plane some bevels to get a feel for it, I have a digital bevel that I can check if the plane work is any good. I understand that the next stage would be laying the components out across the former to see how they join.


----------



## Jacob

simonms":wd50plat said:


> ... I have a digital bevel that I can check if the plane work is any good. I understand that the next stage would be laying the components out across the former to see how they join.


T'other way around - you check your bevels by laying the components out and seeing how they fit. A digital bevel won't help at all.
OK I've said it before. :roll: But it's vaguely fascinating following somebody trying to make a simple job as difficult as possible by using as many machines and gadgets as possible. :lol: 
Are you a Heath Robinson fan?
Not sure what the point is. Why not just get someone to do it for you?


----------



## simonms

Ok then, thanks for all the constructive advice, I will take it all on board but proceed on my own from here.

Thanks.


----------



## Inspector

If you are going to CNC the form you might as well CNC the staves at the same time.

Pete


----------



## MikeG.

simonms":2zk4b8zb said:


> ........I have a digital bevel that I can check if the plane work is any good.....



I thought we'd established that they don't need to be good. This is going to be painted. You are over-thinking this, I'm afraid. Make the form. Take two strokes off each edge of the first 2 staves with a plane. Offer them up to the form. Adjust if necessary. Move on to the third stave. Post WIP photos. It's really that simple.


----------



## simonms

Thanks Mike and Jacob, I hear you. I just wanted to try out a few recommended ways of planing i.e skewing the blade, shooting board with shims etc before I attempted anything else.

I have only ever used a router to copy curves from a template hence the CNC'ed formers. I wouldn't know how to approach making the formers by hand.


----------



## Jacob

simonms":3ggywvol said:


> .... I wouldn't know how to approach making the formers by hand.


band saw, frame saw, coping saw, or router at a pinch.


----------



## Eric The Viking

This is just a horn-loaded speaker, isn't it? How much power (RMS, in the relevant low frequency band please) will be going into it? If this is a HiFi design, read on, as it may save you a lot of effort. If it's high-power PA (or instrument amplification), all bets are off...

I suspect you are simply making loads of unnecessary work for yourself.

The problem overall isn't a woodworking one. You have other options. Firstly, IIRC, you want a segment of a parabola as the curve. if you can draw it or plot it you can make the formers. You then have a variety of options as to the material: kerfed sheet, bendy ply, fibreglass on chicken mesh on a frame.

To go over a bit of acoustics in rather lay terms: 

1. The whole point of the horn is efficient coupling between the drive unit (whatever that is), and the ambient air. You're converting a high-excursion piston effect with big pressure changes into a much wider wavefront, but one that's got smaller changes in pressure. In other words, the horn is an acoustic "transformer".

2. This will be working at low frequencies, with relatively long wavelengths (say around 10 feet, which is roughly the wavelength of sound in air at 100Hz). These frequencies don't couple well into a solid medium such as wood, masonry glass fibre, or whatever, especially if it's not part of a resonant system (part of the point of a horn is that it is _not_ resonant across its width). Aside: I'm ignoring the axial coupling here as it's not all that important, because...

3. ... The pressure waves move tangentially (i.e. parallel) to the horn's surfaces, or they should. There is very little resonance across the horn for several reasons: (1) there's no force acting to cause them; (2) the sides of the horn aren't parallel.

The point of all the above is that, _ceteris paribus_ the construction probably doesn't need to be anything like as heavy and rigid as you think. If your design has parallel sides in the other axis (or sloping ones), you should get ample rigidity from bendy ply--if in doubt use two thicknesses laminated together--or use the ply as a former to make the actual surface in fibreglass, which you can reinforce to your heart's content behind the scenes.

Am I missing something fundamental here?


----------



## Jacob

Eric The Viking":2plaownz said:


> ......
> Am I missing something fundamental here?


Yep. 
Basically our OP knows very little about woodwork. OK we all have to start from somewhere but it's much harder if you don't know how much you don't know. 
And it doesn't help being offered a misleading selection of expensive gadgets and tools, supposedly to help at every stage.


----------



## Eric The Viking

He doesn't need to do what he thinks he needs to do - I suspect.

I await the reply.


----------



## OscarG

Eric The Viking":jaxrnqkq said:


> This is just a horn-loaded speaker, isn't it? How much power (RMS, in the relevant low frequency band please) will be going into it? If this is a HiFi design, read on, as it may save you a lot of effort. If it's high-power PA (or instrument amplification), all bets are off...
> 
> I suspect you are simply making loads of unnecessary work for yourself.
> 
> The problem overall isn't a woodworking one. You have other options. Firstly, IIRC, you want a segment of a parabola as the curve. if you can draw it or plot it you can make the formers. You then have a variety of options as to the material: kerfed sheet, bendy ply, fibreglass on chicken mesh on a frame.
> 
> To go over a bit of acoustics in rather lay terms:
> 
> 1. The whole point of the horn is efficient coupling between the drive unit (whatever that is), and the ambient air. You're converting a high-excursion piston effect with big pressure changes into a much wider wavefront, but one that's got smaller changes in pressure. In other words, the horn is an acoustic "transformer".
> 
> 2. This will be working at low frequencies, with relatively long wavelengths (say around 10 feet, which is roughly the wavelength of sound in air at 100Hz). These frequencies don't couple well into a solid medium such as wood, masonry glass fibre, or whatever, especially if it's not part of a resonant system (part of the point of a horn is that it is _not_ resonant across its width). Aside: I'm ignoring the axial coupling here as it's not all that important, because...
> 
> 3. ... The pressure waves move tangentially (i.e. parallel) to the horn's surfaces, or they should. There is very little resonance across the horn for several reasons: (1) there's no force acting to cause them; (2) the sides of the horn aren't parallel.
> 
> The point of all the above is that, _ceteris paribus_ the construction probably doesn't need to be anything like as heavy and rigid as you think. If your design has parallel sides in the other axis (or sloping ones), you should get ample rigidity from bendy ply--if in doubt use two thicknesses laminated together--or use the ply as a former to make the actual surface in fibreglass, which you can reinforce to your heart's content behind the scenes.
> 
> Am I missing something fundamental here?



I get what you're saying....but this one goes to 11 :wink:


----------



## Eric The Viking

Ah, so it's Stonehenge he'll be wanting then...


----------



## simonms

Thanks Eric,

Disinclined to get into horn theory here and the horn I am looking to make is a pre existing creation as stated back in thread, so I am essentially trying to copy it hence the discussion on how it might have been made. 

Keeping things practical i.e looking at the curve I am trying to create in the materials pre decided is the question. I think it's time for practical work now. Jacob, I have a plane, a bench and some poplar, thats it. I may get the form work cnc'ed as it's easy, free and convenient so no gadgets.

I think the way forward is to do exactly what Mike and Jacob have suggested a few pages back, you're right I am over thinking it.

Oscar, these horns any very efficient only a few watts is needed, 11 would dangerous.

I will post back with my efforts so you can point and laugh....but remember a student is only as good as his teacher so when this goes horribly wrong the blame will be entirely on you


----------



## OscarG

Ha.. I know my guitar amp, Fx pedals stuff but "proper" high-fi and the uber technical stuff Eric the Viking is talking about actually makes my brain hurt!

I'm a complete newbie in terms of woodworking, so I bow to the vastly superior knowledge of the others on here but I think if you are gonna paint this this I would consider the router option.

You've already got the CAD drawing of your exact shape, if you can print out lifesize (on several bits of paper) stick it on some thin mdf, cut round it, slowly sand to the lines.

I mean you've only really got one tricky bit which is making that template, the rest of it will be tedious repetition making the duplicates. It's not the "cleverest" option but in some ways it takes the thinking/guess work out of it and turns it into a low-tech production line job.

It's easy to get bog downed with over thinking something, sometimes I think you've just gotta crack on and get started. If you mess up it's only a bit of poplar right. Not like you've wasted some precious rare wood.


----------



## thetyreman

I'd be concerned about harmonics coming out from the solid wood, because it resonates and creates unwanted harmonics in the sound, have you considered using MDF instead? may as well if you are CNCing it.


----------



## simonms

Thanks, 

As I have said the materials (poplar) have been chosen for me by virtue of the speaker I am copying but have no fear, they sound fine.

I drew up the former for the initial curve last night but again, having not done this before I wonder if anyone would be kind enough to comment on my initial idea, feel free to suggest alternative ideas or areas where this might be improved. Obviously this needs to stay square and that is the area of concern.

Thanks again.


----------



## worn thumbs

Good luck with the 934.33mm.If that sort of accuracy is required you might have to tell your pal with the CNC router to make sure his chordal deviation settings are set to suit.You don't mention whether there is any allowance for trimming the length later,or if you intend to use slightly overlength staves and trim them to the former.I think you might do yourself a favour if you add a triangular web in the corners to maintain the squareness too.


----------



## simonms

Thanks, 

I will tidy up the drawing once I have the basics down, yes the idea is to overshoot the curve by a few mm at each end and trim to fit.

I am not sure what a triangular web is, could you expand?


----------



## MikeG.

For the *initial *curve? No. Make it in one piece. Again, you are over complicating this. A pair of formers fixed by some battens at right angles and parallel, and off you go with the plane.


----------



## simonms

Thanks Mike, sorry this former will be for a complete curve, there is another to do with a different profile after this one so yes I will be doing it as we have planned i.e doing the entire curve over a former fitting as I go.

So you are saying just the 2 guides with some battens in between.


----------



## worn thumbs

Something like this to stop the former lozenging. Its a quick approximation only.


----------



## simonms

That's great, really appreciate that.


----------



## BigMonka

simonms":3r92ldz4 said:


> Thanks,
> 
> As I have said the materials (poplar) have been chosen for me by virtue of the speaker I am copying but have no fear, they sound fine.
> 
> I drew up the former for the initial curve last night but again, having not done this before I wonder if anyone would be kind enough to comment on my initial idea, feel free to suggest alternative ideas or areas where this might be improved. Obviously this needs to stay square and that is the area of concern.
> 
> Thanks again.


Your former looks like a single curve, whereas I thought from your earlier cross-section on page 2 that it was due to be more like an s-curve?


----------



## simonms

Hi,

Sorry for the confusion, there are 2 curves, one is, as you say an s curve and the other is a c curve for want of a better term.

I think I can make my former do both, one on the top and one on the bottom, see pics.


----------



## simonms




----------



## MikeG.

Oh for goodness sake, this is starting to drive me potty.

Simon.......draw out your full curve full size on the top of two bits of ply or mdf clamped together. Cut this out. Get some scraps of wood to hold them rectilinearly. Start work on your staves.

Why in the name of sweet baby Jebus would you do anything else?


----------



## simonms

Hi Mike,

Thanks for your comments, with the greatest of respect that is what I am doing albeit with 3 guides and ply cross bracing , I posed the question on how to keep the form work square and on the advice of BigMonka (thanks!) drew up a design that would do 2 curves for the price of one i.e it can be flipped through 180 to give me the 2nd form. The staves are 1100mm long, I wanted to be sure that everything stays alligned. I posted my form work to invite comments on whether or not it was suitable so I am assuming you do not believe it is and from what I can ascertain you might think it's a bit OTT for the job at hand? Again, I am a total newcomer please bare that in mind and I am sorry you find this so frustrating.


----------



## MikeG.

Right, so this form is for the (complete) piece we are discussing on one side, and some other unrelated curve that you've not mentioned before on the other? Can you see why that might be causing confusion?


----------



## MikeG.

simonms":267fuscx said:


> .....you might think it's a bit OTT for the job at hand?......



I don't think I've ever seen a bigger mountain made of a more insignificant molehill.


----------



## Inspector

Simon I know you are trying to get a handle on how to make your project but because you have a goal and a start point and basically nothing in the middle at how to, you are over complicating things somewhat. What you are attempting to do is basically coopering, the trade of barrel making. Look at some Youtube videos on coopering barrels or buckets and you'll see what the guys are trying to get at when they say to plane an edge and eyeball it for fit as you fit the staves. You have a form you want to follow which makes it easier since you can lay the two staves together to see how they fit. You can even put a light under to locate the high spots. Now put some masking tap across that joint and put the glue on the joint and close it up in the form. Soon you can do the next when the glue sets. You go down the line until you are done. It's that simple. Mike, having the skill could probably do it by standing the ends on a line drawn on the bench top. The form you're making is overkill and will work fine, especially if you want to make a few hundred over the next few years. :wink: It's your overthinking that has the guys a little exasperated. 

Have a look at this video. Around the 5 minute mark the gent starts shaping the edges and offering them up to each other. That's basically all you need to do except you are moving the plane rather than the wood. 
https://www.youtube.com/watch?v=v4kB7JO ... Jtj-xDMHCa


----------



## Jacob

Inspector":2gyzzyxy said:


> ......
> https://www.youtube.com/watch?v=v4kB7JO ... Jtj-xDMHCa


Excellent vid!


----------



## MikeG.

Inspector":pielitsy said:


> ......Have a look at this video. Around the 5 minute mark the gent starts shaping the edges and offering them up to each other. That's basically all you need to do except you are moving the plane rather than the wood.
> https://www.youtube.com/watch?v=v4kB7JO ... Jtj-xDMHCa



Dowelled coopering! I've not seen that before.


----------



## Inspector

I have to admit I only watched the edge planing and fitting and then stopped because it illustrated what I wanted to say. I didn't watch the whole video until I saw your comment. New to me too.  

Pete


----------



## will1983

Is this done yet?

We're 15 days in, 9 pages and 123 posts....

I'm dying to see this thing when it's finished, there's been so much build up!


----------



## Jacob

will1983":13vz59ji said:


> Is this done yet?
> 
> We're 15 days in, 9 pages and 123 posts....
> 
> I'm dying to see this thing when it's finished, there's been so much build up!


Some way to go. He hasn't asked about sharpening yet! :lol:


----------



## simonms

Yes, very good, moving on...again.

Once the curve is complete can I use my form work to act as a guide to trim the edges? Is it the done thing to run a router over a curved surface?

Jacob, I was going to order an Axminster shapening kit for my plane blades but any thoughts on alternatives would be appreciated


----------



## Inspector

You can use the form to trim the panel to size but, the bottom of the router is flat and you're working on a curved surface so there could be a bit of wobble. Better is to saw a bit outside the form and then hand plane or sand to the final size unless you are certain you can hold the router steady. The router can, depending on the bit, the cut direction, amount your are cutting, splinter off some chunks from the ends at the corners.

Pete


----------



## simonms

Forgot to say thanks for the post re. coopering and the explanation, really interesting and that's a serious plane!

I have a fair bit of experience with a router and have a 1/2" Trend which is not small but have been trying to get to grips with some Japanese saws I bought which might be safer I guess.

Another question, what should I try to smooth the surfaces of the curve, sand?


----------



## Inspector

You're welcome.

I would plane the joints of the convex surfaces and then sand the rest with sanding blocks. It won't take long.

Pete


----------



## worn thumbs

Sanding will get the job done ................................................................................ eventually.I have the choice of using any of a number of curved planes and spokeshaves,together with a few shaped scrapers.
You would be well advised to organise firm support for the concave side as there is a risk of breaking the thing if too much pressure is applied.Probably best to take a sliver or two off the outside of the staves before glue up.


----------



## MikeG.

worn thumbs":2bwyqnyp said:


> Sanding will get the job done ................................................................................ eventually.I have the choice of using any of a number of curved planes and spokeshaves,together with a few shaped scrapers.
> You would be well advised to organise firm support for the concave side as there is a risk of breaking the thing if too much pressure is applied.Probably best to take a sliver or two off the outside of the staves before glue up.



This is why I would have made a form of the other side of the curve. In other words, had a convex former not concave, and put the staves on the outside. They could then stay there for the clean up.


----------



## Inspector

Pssst worn thumbs. I didn't suggest planes and scrapers because he doesn't have that stuff. The thought just occurred to me though that his CNC buddy could put them in the CNC and shape and trim them. Then there would only be some light sanding needed to prep them for finishing. 

Pete


----------



## simonms

Thanks Guys,

That makes sense but I reckon your overthinking it  

I will make your recommended amendments to the former, thanks for that, exactly what I need, your experience is most welcome and helpful. On the convex side theres only 1mm on the peaks, I have planes, cabinet scrapers and sand paper but I wouldn't be out of the question to buy some more tools. I was looking at pattern makers planes but can't find anywhere that sells new ones just yet.


----------



## simonms

Thanks Pete,

I have used CNC before for various horn projects but I don't get any joy out of the process, I am enjoying hand tools and find that gives me a more positive feeling about making things. I think I would rather make something badly by hand than CNC it these days.

This is a pair of horns I did a few years back.


----------



## worn thumbs

If you make the former to suit the other side of the job you still need to support it for the other operation.I would go with the former as planned and after cleaning up the first side,I would stick some wide masking tape to the perfect surface and then cut some ply or MDF formers to a good approximation of the shape so that it can be supported while finishing the other side.A few dabs of hot melt glue and off you go.
If you need a shaped plane,just make one.A chunk of beech and a block plane iron will get you a long way.A good day should do it.For the very moderate curvature on both sides a sharp flat spokeshave will do almost anything necessary.


----------



## simonms

Hi again all,

I am in the process of gluing up my staves and am thinking ahead to fairing out my curve. I did a few trial runs with some pine and on the convex side used my jointer to take away the peaks and sanded it out. On the concave side I cut some sanding blocks conforming to the curve and used those which worked nicely but was time consuming. I used a cabinet scraper to remove any residual glue.

Has anybody got any further suggestions to ease this process, I was looking at sanders with an "interface" pad but just wanted to check in for any other ideas or thoughts.

Cheers,

Si.


----------



## AndyT

A large round soled plane.
This would be an old, wooden plane but don't let that put you off.
Large sizes of hollows and rounds are not often needed, so often survive in good condition from sets. Look on eBay or at the handful of real world used tool dealers. Expect to pay no more than a tenner.


----------



## Benchwayze

Simon. 

The only time I ever did any 'coopered' work, was a bow-fronted pine corner cupboard for a dealer. 
To make the doors, I built an accurate 'former' of MDF, clamped it to my bench, and got out a Record No. 6. 

I hadn't a clue about coopering, but I could make a good rubbed joint. So, I merely planed a bevel on the edge of the first lath, and then fitted the next one to suit. I continued like that until I was knee-deep in shavings and had two curved doors. I'm sure all the bevels were different, but they all fitted properly. I achieved what I wanted without too much trouble, and as far as I know the cupboard is still okay. I doubt very much if that was the proper way to do it, but it worked. I never had any negative feed-back anyhow. The dealer BTW was a friend (Sadly now passed) and he probably made four times the price he gave me, but hey; what are friends for? 8) 

The difficult part was removing the 'flats' from the inside curves, but I picked up a rounded sole moulding plane at an antique fair, and did it with that! The laths were certainly a lot thinner than when I started, but that was fine, as the doors looked all the more elegant; well I think they did! 

All, that probably won't help, but I can always hope!" 

All the best Simon.

John


----------



## MikeG.

Benchwayze":2616h0mj said:


> ........ I doubt very much if that was the proper way to do it....



No, John, it absolutely was the proper way to do it.


----------



## Benchwayze

Thanks Mike. 

I truly didn't realise that. Never done work like that before or since. It just seemed the most common-sense way to me. I always believed I was a 'born' woodworker'! :mrgreen: Yeah, right!
My 'Mentor' ( mentioned below) used to say, 'Never, as long as you have a hole under your nose!' 

But I think he was joking! I hope... 

Thanks again Mike. 

John (hammer)


----------



## simonms

Thanks for the replies, John, my experience was a similar one as predicted by Mike and a few other kind contributors. My drawings acted only as a guide/approximation so began undercutting the bevels and offering them up and adjusted to fit, on some of the really small bevels I just skewed the blade in my jointer which seemed to do the trick. Lots of practice on scrap before I started was a good idea for me. 

I found that some sanding blocks cut to the underside of the curve (concave side) with some 40 grit was enough to shape as they are only shallow curves and then a cabinet scraper worked nicely but I do have some curved bottomed planes turning up to try for the slightly tighter curves I am yet to make.

I used a Veritas jointer with the adjustable fence which was great from a beginners perspective but it wasn't that accurate so really just acted as a guide as I tweaked in the bevels. I am yet to finish the top face of the curve so will report back when I'm done.


----------



## Jacob

simonms":3kvxup1p said:


> .........
> I used a Veritas jointer with the adjustable fence which was great from a beginners perspective but it wasn't that accurate so really just acted as a guide as I tweaked in the bevels. I am yet to finish the top face of the curve so will report back when I'm done.


Fences on hand planes look like a a good idea but they aren't. Just another useless gadget.
Except on rebate planes but even then just to start the cut - it's easier to carry on without it once you've got a rebate started.


----------



## worn thumbs

Jacob clearly has no sympathy for those people who make a meagre iving selling gadgets to woodworkers.They need to find devices that look plausible and which have no equivalent in the market place.Couple that with a few favourable reviews in the comics or online and it helps pay the bills for a bit longer.
I think the average hobbyist would be quite shocked by the tool selection of the average professional and how traditional it tends to be.They do have the advantage of having spent enough time doing things to have learned how to make good use of the tools they have and will buy good enough tools without needing to acquire the brands the online experts promote.Earlier this week I learned of the death of a former foreman and mentor and he produced lots of high quality work fairly rapidly with good,but ordinary tools.His trying plane was old when he bought it from a Scotsman who retired and was wooden and his Stanley No 4 had a sole that had worn quite thin.I know of at least one instance when he needed a plane to clean up a concave surface and by means of a bit of re-shaping of a block plane iron and a beech offcut,he was producing shavings before the morning was out.


----------



## simonms

Hi again guys,

Nearly ready to paint this so am wondering what to use to prep the timber with. I will be painting it with a matt black waterbased paint.

Ant recommendations or advice on the application of things like sanding sealer or shallac before painting welcome.


----------



## Inspector

The paint you pick should tell you what primer to use on the can. 

Pete


----------



## simonms

Thanks Pete,

I have bought some Bedec Multi surface paint which I have used before, it says no primer required but just wanted to pose the question to see if anyone might consider it a sensible move to use something before the paint is applied.


----------



## MikeG.

You won't get better than the Bedec MSP, and you use it precisely the way it says on the tin.


----------



## simonms

Update from Jan.2019.

Long time has passed but just wanted to update with a couple of pictures. The first is one of the back sections of the horn, twisted sides and the other is the larger front section, the 2 join together to make the wooden horn. Thanks for all the help here, very grateful.


----------



## Cabinetman

Interesting loudspeaker design. I can imagine what my Pam would say to those ha ha. 
Just mention could you perhaps add onto the title, update from January 2019? Ian


----------



## simonms

Cabinetman said:


> Interesting loudspeaker design. I can imagine what my Pam would say to those ha ha.
> Just mention could you perhaps add onto the title, update from January 2019? Ian


Cheers, just edited the thread, these horns were first made in the 1920's by Western Electric, heres a You tube clip of some playing.


----------

