Mitres are harder than dovetails!

[Eric The Viking]

Cheers wizer but it's the 45deg I can't get fof the shooting board in the first place. It's a Catch 22. I need a 45deg "thing" to make the 45deg thing that I need to make 45deg things!

Large piece of paper, ruler and a pair of compasses:

Step 1: Draw a line near one edge of the paper and roughly parallel to it. mark a point near the middle. Set your compasses to, say around 3 inch gap. Put the point on the mark, and make two new marks on the line, either side (these are equidistant from your first point). This is what you should have:

Step 2: Make a right-angle: Open the compasses slightly more. put the point on one of the new marks and make an arc roughly over your original point in the centre of the line. Repeat on the other side, being careful not to change the compass setting. Join the point where the arcs cross with your original point for a near-perfect right angle:

Step 3: your semicircle from step one gives you a crossing point on your new right angled line. Use this, with one of your original marks (in the red circles below), as centres. make two new arcs with the compasses: where they cross is the bisector of the angle (this works for any angle, obviously).

The straight line running through this and your very first point is at 45 degrees to your original line.

This method is as old as the hills and as accurate as your ability to draw straight lines and keep the compasses' pencil sharp, and will be better the bigger-scale you draw it out to. A drawing-pin and string works too, if you only have a pencil and no compass!

Once you have an accurate 45 degree angle (and you can draw this straight onto MDF, obviously) you have the basis for your shooting board...

Once again, apologies if I'm telling granny about egg-sucking, but judging from what my teenage children tell me, formal geometry is no longer taught in schools: if you're young, there's no reason why you should ever have done this before, and there's no shame in not knowing how!

 

[promhandicam]

For fear of being given a boll**king by wizer for reviving an old thread this is how I did all the mitres for the **** beadingon this job - 116 joints in total so 232 cuts!

I made up a jig on out of some 2.4m long offcuts of mdf for my scms which I then screwed to the saw. The jig has a short section of 6mm mdf at the front which effectively grips the **** beading. The saw is locked in position so that it acts like chop saw and the depth of cut is also set so that it doesn't cut the jig in half.

One mitre is cut and then the beading is measured against the door / drawer front and marked with a pencil on the rear face. This mark is lined up with the front left hand side of the saw cut in the jig.

Opposite pieces were marked up from each other and if necessary it was possible to adjust a piece by taking off the lightest of cuts without any breakout as the beading was supported right up to the blade. At the end all of the mitres were perfect without any buggering around with shooting boards or even shuteing boards - whatever they are :roll: The only tools needed once the jig was made, was the scms and a pencil.

Hope this helps someone,

Steve

 

[BradNaylor]

I'm afraid I just don't understand the problem with mitres. I do loads of them and have never used a shooting board in my life.

I use this.

So long as it is well set up and the blade is nice and sharp I get perfect results every time. As you can see it's well used!

 

[RogerS]

No-one mentioned the Axminster Mitre Triimer? Perfect results every time.

 

[chingerspy]

I'm about to make a couple of shooting boards for the shop.

However, if I was going to be doing lots of mitres, say for picture frames or boxes I'd go with RogerS' suggestion and invest in a mitre trimmer. If you are doing a lot of them they seem well priced for a specialised tool.

 

[Jeff Gorman]

There's some material about shooting boards at:

http://tinyurl.com/yevhfx9
and
http://tinyurl.com/yeqt8tc

The principle difficulty with the illustrated type of Donkey's Ear Shoot is holding a weighty piece in place.

Although I've not got one, the wedged box (foot of the Donkey's Ear Shoot page) should be easy to make and worth a try.

Also a screw-operated mitre block can be well worth making (or even finding?)

I did a couple of pieces about making one in Good Woodworking 188 & 189.

Best of luck!

Jeff
www.amgron.clara.net

 

[woodbloke]

I'm afraid I just don't understand the problem with mitres. I do loads of them and have never used a shooting board in my life.

I use this.

So long as it is well set up and the blade is nice and sharp I get perfect results every time. As you can see it's well used!

Try making eight 120mm accurate long mitres for the corners of a box with that thing...good for site work, but I wouldn't have one in my 'shop - Rob

 

[SBJ]

Rob - that's a pretty snobby response if you ask me.

Have a look here - the mitres on the strings/risers were done with a circular saw and are perfect. (or should I say accurate, and really long, as they are bigger than the benchmark 120mm for longness???)

Sometimes it's not the tools that cause the problems, it's the attitude.

 

[woodbloke]

Rob - that's a pretty snobby response if you ask me.

Have a look here - the mitres on the strings/risers were done with a circular saw and are perfect. (or should I say accurate, and really long, as they are bigger than the benchmark 120mm for longness???)

Sometimes it's not the tools that cause the problems, it's the attitude.

Au contraire :wink: The stuff shown in the link is impressive, but there's probably a misunderstanding in terms at play here. Long mitres are those that you'd expect to find in something like this:

(these are secret mitred btw) Making eight accurate mitres (so that each pair of sides is identical) with one of those machines can't (as far as I know, and would like to be proved wrong) be done.
Essentially these machines are for work on site where they are indispensable but they find little use in a professional cabinet 'shop (and I've been in a few) because although they may be accurate...they're not accurate enough.
The only use I could see for one in a cabinet 'shop would be for cutting long boards across the grain...but then that's what a decent hand saw or Skil saw's for, init? - Rob

 

[frugal]

I must confess that I have tried to finish mitres by hand with a plane and a shooting board, but I just can not get on with it. It it probably as much to do with the shooting board as with me, it is not that great. Now I cut them roughly and then finish them on the disc sander. I can drop the table down to 45 degrees and that gives me enough accuracy to make boxes with. IT also means that I can take off a tiny fraction at a time so that they all line up.

I fully expect that a finely fettled shooting board and a finely fettled mitre saw will both give excellent results, the only difference is what skill the operator has at fettling that particular tool.

 

[John. B]

This may be the answer :roll:
http://cgi.ebay.co.uk/MAGNOLIA-MITRE-GU ... 1e5b3b0d12
Looks cheap at the price :?
The only downside is having to go to Lavenham to pick it up :? (Suffolk)

John. B

 

[DaveL]

The only downside is having to go to Lavenham to pick it up :? (Suffolk)

That's just up the road from here, nice place, but I don't think I could get that in the workshop, let alone the car. :roll:

 

[SBJ]

Au contraire :wink: The stuff shown in the link is impressive, but there's probably a misunderstanding in terms at play here. Long mitres are those that you'd expect to find in something like this:

(these are secret mitred btw) Making eight accurate mitres (so that each pair of sides is identical) with one of those machines can't (as far as I know, and would like to be proved wrong) be done.
Essentially these machines are for work on site where they are indispensable but they find little use in a professional cabinet 'shop (and I've been in a few) because although they may be accurate...they're not accurate enough.
The only use I could see for one in a cabinet 'shop would be for cutting long boards across the grain...but then that's what a decent hand saw or Skil saw's for, init? - Rob

I'm not sure I follow you Rob - the mitres on the join between the riser and the string are about 200mm long - and dead on accurate. Admittedly it's only one corner/joint but i'm sure a box could be done using the same methods.

 

[woodbloke]

I'm not sure I follow you Rob - the mitres on the join between the riser and the string are about 200mm long - and dead on accurate. Admittedly it's only one corner/joint but i'm sure a box could be done using the same methods.

Correct me if I'm wrong, but the tool used to cut the risers in your linky isn't an SCMS or similar as posted in Brads piccy...it's a green Festooly saw which ain't the same beast.
My point is that it's almost impossible to cut a set of long mitres for box work using the sort of tool (or similar) posted in Brads pic...even if you had hold of Waka's Kapex - Rob

 

[Mattty]

I'm not sure I follow you Rob - the mitres on the join between the riser and the string are about 200mm long - and dead on accurate. Admittedly it's only one corner/joint but i'm sure a box could be done using the same methods.

Correct me if I'm wrong, but the tool used to cut the risers in your linky isn't an SCMS or similar as posted in Brads piccy...it's a green Festooly saw which ain't the same beast.
My point is that it's almost impossible to cut a set of long mitres for box work using the sort of tool (or similar) posted in Brads pic...even if you had hold of Waka's Kapex - Rob

I have to admit i think your wrong here Rob. I have the same scms as Duncan and with a good blade i can cut 4 identical box sides with mitres that are 100%.
I do a lot of traditional cabinet work and whilst i own, and very occasionally use a shooting board i don't use it for mitres. I'm not saying it is wrong to use a shooting board but i do think that there are more efficient ways.
I would also disagree- I think 99% of cabinet shops would have a SCMS these days and most would look to use there machinery for any job they can because it is more efficient.

 

[woodbloke]

Best to leave it there then chaps. As ever, there's usually more than one way to skin the proverbial :wink:
...pics would be good though Matt to see how it's done with a SCMS - Rob

 

[OPJ]

Rob, just to confirm, I seem to remember the corner joints on your casket were secret mitred dovetails? Not just your average mitres!

That may be where the confusion lies here... In which case, I'd agree that you couldn't cut much of those joints on a SCMS or table saw, for that matter.

 

[promhandicam]

. . . . I think 99% of cabinet shops would have a SCMS these days and most would look to use there machinery for any job they can because it is more efficient.

I thought a quick poll might help to sort this out - see here. I personally think that the vast majority of professional cabinet makers will use the quickest most practical method to do any particular job to an acceptable standard. That means power tools for the majority of operations because at the end of the day time is money. For most customers the overall cost is probably the major deciding factor in placing an order. I don't doubt that there are makers who only use hand tools - a la Saint Jim - but they cater to a very small minority of customers who are buying a piece for who made it as much or more so than for what it is. It will be interesting to see how the poll turns out.

Steve

 

[woodbloke]

Rob, just to confirm, I seem to remember the corner joints on your casket were secret mitred dovetails? Not just your average mitres!

That may be where the confusion lies here... In which case, I'd agree that you couldn't cut much of those joints on a SCMS or table saw, for that matter.

Agreed Olly...but I did say that :wink: I'm talking about a straight forward long mitre 120mm long on the corner of a box that could say, be reinforced with a few splines after it's glued
Ref Steve's poll, mitres like this in a professional 'shop would be cut with a table saw, not a SCMS...unless you can tilt one to 45deg? - Rob

 

[Mattty]

Rob, just to confirm, I seem to remember the corner joints on your casket were secret mitred dovetails? Not just your average mitres!

That may be where the confusion lies here... In which case, I'd agree that you couldn't cut much of those joints on a SCMS or table saw, for that matter.

Agreed Olly...but I did say that :wink: I'm talking about a straight forward long mitre 120mm long on the corner of a box that could say, be reinforced with a few splines after it's glued
Ref Steve's poll, mitres like this in a professional 'shop would be cut with a table saw, not a SCMS...unless you can tilt one to 45deg? - Rob

I agree Rob a TS is the most likely choice, surely it depends on the kit available to the user though. For example i have a sedgwick TA 315. I wouldn't rate it at cross cutting generally and not for something as delicate as cutting mitres for a box. Yet this is quite a common trade saw.

I only commented because you seemed to be discounting something because you personally have a lack of experience with the machine. When in actuall fact SCMS's can be fantastically accurate and can more easily handle longer material than most TS sliding tables can.
Horses for courses- all i'm saying is that i can very easily cut mitres with a scms.

All SCMS can tilt to 45degrees (the C stands for compound... i think!)