Thickness normalising before or after routing parts?

[julianf]

Ive been making parts like these (excuse the logos - im not trying to sell here, but they were applied and i cant be bothered to find the un-logo'd original files)

The parts are about 18mm thick.

What i have been doing is flattening the sheet, and then cutting the parts, but am i doing this the wrong way around?

Im working from rough sawn, and, sometimes the boards have quite a cup, so it requires thought to get the 18mm out of, say, a 1" board.

Would i do better cutting the part out of the best part of a cupped board, and then running the finished part through a drum sander (not that i have one of them!) to flatten it out and take it down to thickness?

I have a thickenesser, but that will, im sure, just chew up the job.


This kind of leads on from my plans to make a router sled, but the current boards are so cupped that im really wondering if cutting the parts first might work better.

What do you think?

 

[TheTiddles]

All those approaches may work, but.... what are they?!

I’m often surprised how well my thicknesser does on some quite tricky grain (when it’s sharp), when it makes a mess I need to remember to sharpen the blades more

Aidan

 

[Yojevol]

I would cut the boards roughly into your shapes but leave wide margins - don't attempt to cut the detail. Flatten them. Leave them to rest for as long as possible. Flatten them again. Shape to final design. Sand and polish.
Brian

 

[Rorton]

look like vintage keyboard end panels to me ? I think I would get to a rough size from the board, then flatten, and then cut final shape.

If you are using a router sled, you probably need the board your flattening in some sort of regular shape otherwise the cutter bit may get a bit funny on the corners? you can reduce the amount you need to remove from a board of you cut it to rough size first and then flatten, instead of flattening a whole board (unless your whole boards are close to final size anyway?) as you may remove some of the severity of the cup by getting rid of excess material you won't use.

Thicknesser could work - maybe need to make a sled that is flat for the cupped board to sit on while passing through the thicknesser, cupped side facing down and then pass through so you get one flat side, then pass back through again with the new flat side down?

 

[julianf]

The parts are for this kind of thing -

(posted these photos the other day in another section here)

Im cutting these on a cnc machine, but they would probably be quicker to do on a bandsaw and then a manual router table - neither of which i have!

At the moment ive been using the cnc to flatten the job, but its just tedious doing it like that. I need to be able to make them quicker than im doing so currently. They sell, but only up to a certain price, and, at the moment, my hourly rate as a function of end price is not great! So i need to keep the price the same, and get them made quicker.



In the photo above, theres a couple on the same sheet, but the latest lot wouldnt tessilate on the width of the board, so will just be done as singles.

Because im cnc cutting them and not running on a router table, i need a load of margin to sensibly hold the part. Again, a manual router table may be a better idea here.

Brian, you say cut to rough size, then flatten - how would you go about flattening them?


I was not planning on using the router sled after the outline was cut, as, like Rorton says, ill mash up the edges. Its ropey timber (which is the whole appeal when finished!) and the edges will fail against a cutter.

I always look at my thicknesser (axminster 106) as more of a roughing tool, than a finishing one, and id have no confidence at all in feeding it finished parts. They would catch, spin around, and get eaten, im sure!


I figured drum sanders would be more gentle? Ive never used one.... Sadly, from my casual watching of these things, they seem to be much more expensive than you might expect (when compared to other tools, like thicknessers, table saws, or, virtually anything else!) Even a cheap axmister one is £500 used, it seems?

 

[Ttrees]

A drum sander wouldn't be great for unstable stock, clog easily, be expensive, take ages, and be very dusty.
You could hand plane them very quickly compared.
Just my opinion though.
Tom

 

[julianf]

You could hand plane them very quickly compared.

You've seen me with hand tools, right?

 

[Ttrees]

You can forgive yourself for being duped into believing some folk.
Some rattle on about this and that, and whatever else.

Watch the good stuff like Charlesworth.
He's the very best at teaching planing techniques.
Not much good tutorials around otherwise, plenty of folks out there
that are in the business of illusion, rather than wanting to share knowledge.
Be aware of those folks.
Rob Cosman's publications are pretty good also, regarding techniques.... if you can sift through the rubbish.
He'd have you spending lots and lots of money, skip through all that.
But at least both of those guys are honest regarding planing technique.
(unfortunatly missing the way a plane should be actually set up like the inventor of the cap iron intended)
Most others are not honest, quite the opposite.
Or at least they think their honest, whichever you think it may be, not great advice.

And lastly, when you have that down, forget about any settings you may have learned regarding the plane from those two, and learn to set a cap iron correctly.
Which, from all I've watched, this info is missing from both of those guys videos.
I've haggled with Cosman about this, but he wants to sell uber expensive sharpening equipment to feed his family.

David Weaver has an excellent article titled 'setting a cap iron'.
About the best information you will find on the subject...
mix with other techniques and it doesn't work!!!

No need to ever scrape timbers, and anyone who suggests doing so, forget about them, as they don't know how a double iron plane (a Bailey design) works.

That weeds out every other mainstream guru out of the equation, if you're looking for videos on the subject.
Well apart from Richard Maguire who only touches on the subject, and in the tutor business so you won't get a complete idea for free on youtube.
and another two do also, but their unknown woodworkers, not mainstream folks, one Spanish, the other not really a woodworking channel specifically.

You will likely need this knowledge for your pieces if you want to be productive.

All the best
Tom

 

[philip sewell]

How times have changed.



I have a cnc machine but I don’t have a bandsaw!

 

[julianf]

How times have changed.



I have a cnc machine but I don’t have a bandsaw!

I'm a metal worker, who has fallen into woodwork. The CNC machine is what I use for alloy.

I have a couple of saws, both metal - varga va-1 (which has a price tag akin to some sort of collectors plane!) and a Rapidor Minor for more significant cuts.

Neither would be any good for wood. Nor the plasma cutter... : )

So, that's the context... Makes more sense with context! : )

 

[julianf]

You can forgive yourself for being duped into believing some folk.
Some rattle on about this and that, and whatever else.

Watch the good stuff like Charlesworth.
He's the very best at teaching planing techniques.
Not much good tutorials around otherwise, plenty of folks out there
that are in the business of illusion, rather than wanting to share knowledge.
Be aware of those folks.
Rob Cosman's publications are pretty good also, regarding techniques.... if you can sift through the rubbish.
He'd have you spending lots and lots of money, skip through all that.
But at least both of those guys are honest regarding planing technique.
(unfortunatly missing the way a plane should be actually set up like the inventor of the cap iron intended)
Most others are not honest, quite the opposite.
Or at least they think their honest, whichever you think it may be, not great advice.

And lastly, when you have that down, forget about any settings you may have learned regarding the plane from those two, and learn to set a cap iron correctly.
Which, from all I've watched, this info is missing from both of those guys videos.
I've haggled with Cosman about this, but he wants to sell uber expensive sharpening equipment to feed his family.

David Weaver has an excellent article titled 'setting a cap iron'.
About the best information you will find on the subject...
mix with other techniques and it doesn't work!!!

No need to ever scrape timbers, and anyone who suggests doing so, forget about them, as they don't know how a double iron plane (a Bailey design) works.

That weeds out every other mainstream guru out of the equation, if you're looking for videos on the subject.
Well apart from Richard Maguire who only touches on the subject, and in the tutor business so you won't get a complete idea for free on youtube.
and another two do also, but their unknown woodworkers, not mainstream folks, one Spanish, the other not really a woodworking channel specifically.

You will likely need this knowledge for your pieces if you want to be productive.

All the best
Tom

Thank you. A very informative post. I will look into your suggestions. It's appreciated.

 

[philip sewell]

Fair enough Julian. Definitely worth investing in a bandsaw if you carry on with the woodwork imo.
If you are worried about wood movement after planing/thicknessing part plane them say 4mm over thickness and plane and thickness again in a day or two, that usually works for me. You can mitigate tearout to a degree on the surfacer by a zigzag motion (so presenting the wood at a 45 ish degree angle-helps if you have a wide planer) as you move over the blades and slow feed, shallow cuts and sharp blades.

 

[sploo]

Depending on your volume/workflow, one good way to make small parts safe for a thicknesser is to glue a pair of sacrificial (e.g. pine) rails either side of the board; overhanging by 5-10cm on each end. Example here (though I did - unadvisedly - use screws on that one, and there are also rails front and back as the below is an end grain board):

This technique also helps to keep the thicknesser snipe away from the actual work piece, and with a few light final passes I find the finish is usually decent even with dodgy timber.

Ttrees' post about hand planes is good; and I'd also suggest Paul Sellers for plane use and tuning advice; though the simplest way might be to find someone local who would go through it with you. A hand plane would give you the option of quickly (and roughly) flattening stock before finishing it in a thicknesser (or on the CNC machine). A light skim with a hand plane (or a few strokes with a card scraper) can also help to improve the finish from a thicknesser.

 

[Cabinetman]

You can forgive yourself for being duped into believing some folk.
Some rattle on about this and that, and whatever else.

Watch the good stuff like Charlesworth.
He's the very best at teaching planing techniques.
Not much good tutorials around otherwise, plenty of folks out there
that are in the business of illusion, rather than wanting to share knowledge.
Be aware of those folks.
Rob Cosman's publications are pretty good also, regarding techniques.... if you can sift through the rubbish.
He'd have you spending lots and lots of money, skip through all that.
But at least both of those guys are honest regarding planing technique.
(unfortunatly missing the way a plane should be actually set up like the inventor of the cap iron intended)
Most others are not honest, quite the opposite.
Or at least they think their honest, whichever you think it may be, not great advice.

And lastly, when you have that down, forget about any settings you may have learned regarding the plane from those two, and learn to set a cap iron correctly.
Which, from all I've watched, this info is missing from both of those guys videos.
I've haggled with Cosman about this, but he wants to sell uber expensive sharpening equipment to feed his family.

David Weaver has an excellent article titled 'setting a cap iron'.
About the best information you will find on the subject...
mix with other techniques and it doesn't work!!!

No need to ever scrape timbers, and anyone who suggests doing so, forget about them, as they don't know how a double iron plane (a Bailey design) works.

That weeds out every other mainstream guru out of the equation, if you're looking for videos on the subject.
Well apart from Richard Maguire who only touches on the subject, and in the tutor business so you won't get a complete idea for free on youtube.
and another two do also, but their unknown woodworkers, not mainstream folks, one Spanish, the other not really a woodworking channel specifically.

You will likely need this knowledge for your pieces if you want to be productive.

All the best
Tom

Hi Tom, I hadn’t seen that David Weaver article before, spot-on information and I agree entirely with what you’ve written here. People make such a fuss and a todoment, when really it’s quite simple, and don’t get me started on sandpaper! The finish from a well set up plane is superb, it shines, why people then want to scratch the surface of the wood is beyond me.
Julian, if you have a good planer/thicknesser there are very few timbers that it couldn’t deal with successfully, those little knots on those bits of wood wouldn’t cause any problems at all. It probably wouldn’t make a great deal of difference whether you thinned first or shaped first but for me I would thin it first. Ian

 

[Jacob]

Shaping and reducing in size first generally means having to remove less material to flatten.
You could cut out a rough blank first (band saw) then thickness without necessarily having to flatten one side first- those bench top thicknessers are much better than they look if kept sharp and you can just turn the piece over between passes, putting it through concave side down first one or two passes, so it doesn't rock.
Then shape with band saw and finish edges with drum sander of appropriate size?
Unless you are just doing a sampler or two I wouldn't dream of hand planing.
PS just spotted Yojevol and others saying much the same - rough shape first etc.

 

[Amateur]

In my opinion, and from what you've said.
This is production and cost sensitive.
I'd be inclined to use 18 mill veneered ply.
it's cheap will look good and the end sanded and stained will not detract from the overall appearance.
Why go to anymore trouble?
Nest your pieces on an 8x4 sheet press the button and away you go.
I think your making this more complicated that it needs to be.

one other thing.
price is relative.
making money on Heath Robinson is very difficult to do.
over engineering increases cost.
Understanding the right material for the job in hand is paramount.

 

[Amateur]

If the wood isn't stabilised to environmental working\ use conditions it will continue to bow, and twist.

 

[julianf]

I'd be inclined to use 18 mill veneered ply.

Would not sell at all

making money on Heath Robinson is very difficult to do.

That's precisely the reason I'm posting here. I have no issue buying tools, if they pay for themselves.

 

[julianf]

Shaping and reducing in size first generally means having to remove less material to flatten.
You could cut out a rough blank first (band saw) then thickness without necessarily having to flatten one side first- those bench top thicknessers are much better than they look if kept sharp and you can just turn the piece over between passes, putting it through concave side down first one or two passes, so it doesn't rock.
Then shape with band saw and finish edges with drum sander of appropriate size?
Unless you are just doing a sampler or two I wouldn't dream of hand planing.
PS just spotted Yojevol and others saying much the same - rough shape first etc.

This is along the lines of what i was thinking - rather than flattening the whole job, and removing more material than i need to, due to cupping etc, get the shape and THEN flatten, so as i get a flat surface but am able to maintain as much of the thickness as possible.

I have an axminster 106pt. Even with brand new blades, i always look at it as more of a roughing tool than a finishing one though. The trouble is, if it takes a scalp out of some bit of figured grain, its basically wrecked that job.

From what i see, drum sanders are more gentle, and less likely to write off a part in the blink of an eye?

 

[Jacob]

This is along the lines of what i was thinking - rather than flattening the whole job, and removing more material than i need to, due to cupping etc, get the shape and THEN flatten, so as i get a flat surface but am able to maintain as much of the thickness as possible.

I have an axminster 106pt. Even with brand new blades, i always look at it as more of a roughing tool than a finishing one though. The trouble is, if it takes a scalp out of some bit of figured grain, its basically wrecked that job.

From what i see, drum sanders are more gentle, and less likely to write off a part in the blink of an eye?

Might be worth just using the thicknesser for both sides as I described above - don't attempt dodgy looking grain over the top of the machine - the built in power feed makes a huge difference to the cut. You'd have to put the pieces through concave side down to start with, so they can't rock about. If a piece is really twisted perhaps just take a corner off over the top so it will go though the thicknesser without rocking.
A machine with slower feed rate but higher cutter rpm would be good - this is why some of the "toaster" thicknessers are better than you'd expect.
Come to think, Amateur's suggestion is a good one. You could buy decorative veneer and apply it to 18mm ply yourself. Endless classy decorative possibilities!