Thread: Mitred edges box

I always do my mitres on the disc sander, or you can do it on a linisher. Set up the table square to the face of the sander, and clamp a fence to the table at 45 deg. You can check the angle by doing 2 mitres on some scrap, and check that they make a right angle when put together.
Mark out the mitres using a marking knife. When you sand the mitres, you will get a fine 'feather' when you reach the line.

Thanks Alex I have one of those cheap disc sanders that isn't all that accurate but I'll give it a try, it should get it pretty close to a decent angle after some experimentation.

Hi Tiger,

What make of SCMS do you have and how far away from 45 is it? Is it actually the faces of the mitres that don't equal 90 or is there some discrepancy along the length of the join? Maybe a picture or two to assist us?

Regards,

Rob

Tiger,
You seem to have got a lot of information in your thread about shooting boards. You have asked for similar advice here. Maybe just keep to one thread or at least let people answering this thread know what's already been offered and tried!

I use a table saw and go straight to glue up without further steps. I have done them with a well set up scms. It's obviously important to have the scms crosscutting a perfect 90º, beveled at a perfect 45º and it is critical to use stops to get two pairs of perfectly length-matched boards. Two other things are very important; clamp the work down so it cannot move and make the stock long enough that cuts on both ends detach some waste ie, do not try to 'nibble' or fine tune an end. scms have a nasty habit of deflecting that little bit if you do, so make sure the cuts are fully buried in the board.

Hi Rob,

My SCMS is a Ryobi so not a high-end machine, not had much luck with it getting a perfect cut in either dimension, along the cut as well as the 45 degree angle but it's close.

In regard to double posting, one question is regarding shooting boards, here I'm asking about other methods that can be used to achieve my objective, there may be a little overlap but I would like to hear from box makers as that is what I'm ultimately trying to achieve here.

Thanks Mic-d, not sure if my Ryobi will ever give me that sort of accuracy, but how does a SCMS go when cutting small pieces ie the ends of small boxes?

As you've found out, close isn't 45. How do you mean you can't get a straight line along the length of the cut? Does this mean you've got twisting happening along the blade as well as an incorrectly set angle? If so, a shooting board probably isn't going to help too much.
I am prepared to give you time in my workshop and go over the basics of SCMS use for making mitres if you wish. You can try out a table saw as well. Send me a PM if you do. I'm fine this afternoon or tomorrow.

Regards,

Rob

Originally Posted by LGS

As you've found out, close isn't 45. How do you mean you can't get a straight line along the length of the cut? Does this mean you've got twisting happening along the blade as well as an incorrectly set angle? If so, a shooting board probably isn't going to help too much.
I am prepared to give you time in my workshop and go over the basics of SCMS use for making mitres if you wish. You can try out a table saw as well. Send me a PM if you do. I'm fine this afternoon or tomorrow.

Regards,

Rob

Thanks Rob, the SCMS I never regarded as a precision tool, fine for carpentry but I've never had dead-on accuracy not with a Ryobi anyway. The blade is still the original one I've got and I never expected much from it. It's difficult to set a precise angle on it for bevels as it's got a knob at the back, does not allow for fine tuning and I've had slight twist perhaps as a result of not being able to clamp the piece adequately.

Originally Posted by Tiger

Thanks Mic-d, not sure if my Ryobi will ever give me that sort of accuracy, but how does a SCMS go when cutting small pieces ie the ends of small boxes?

I had good results with my scms, it was an Elu though. Don't have it any longer. I dare say you would get good results with a plain CMS, they are usually a bit more rigid than an scms. (that's given me an idea of something else to try - try locking the slides in the full forward position - might sitffen it up a bit -assuming of course that there is enough width of cut without the slide function) If you get yourself a digital angle gauge that may be a convenient way to adjust your bevel if you're having trouble with it.

Originally Posted by Tiger

The blade is still the original one I've got and I never expected much from it. It's difficult to set a precise angle on it for bevels as it's got a knob at the back, does not allow for fine tuning and I've had slight twist perhaps as a result of not being able to clamp the piece adequately.

Tiger, the Makita LS1214 uses a knob at the back and I get excellent mitres off that. Maybe if you try using a new blade from Makita or DeWalt or CMT if possible, with about 60 teeth you'll get rid of the twist and get an accurate angle. Mic's suggestion of an angle reader is a very good one too.

Rob

I use my table saw, I roll the blade over using a digital angle gauge to get 45 deg, I mount the wood on a sled with clamps to hold the wood down, I also used stops to ensure the cut lengths are the same.

I then lay the sides edge to edge flat along my bench with the inside facing down and run masking tape along the front sides I then roll the sides over and put my glue (horse sauce) on all the mitred cuts and roll it all up and secure the last edge with some more masking tape and leave it to dry. I then cut slots in the edges for keys to strengthen the joint.

Never had an out of square box and all the mitres are always nice and tight.

I also use the same sequence as Phil above with one extra step. When you turn the pieces over after taping but before erecting into a box, I apply masking tape to the inside edges as close as possible to the eventual corner. Then, glue up as Phil has said. The masking tape on the inside takes any excess glue that is squeezed out of the joint and after drying, when removed, means there is virtually no clean required on the inside of the box.

You've been blogged

Originally Posted by mic-d

You've been blogged

?????