Thread: Is there a simple way to tune a mitre joint

I am now officially frustrated.
I have adjusted my workpieces on the modified shooting board.
They are as close to a perfect 45deg as I can measure. The opposing sides are within a hair of being the same length.
Yet still when I dry assemble the fourth side does not fit, seemingly by a fair amount.
The frame started out at 300mm x 230mm (outside dimensions) , its a little bit smaller now, and is 45mm wide (so the inside is 210x140)
I must be doing something wrong but I cant figure it out.

Clint

Clint

Measure the sides. Are they exactly the length needed?

If they are, then the shooting board is actually cutting "out" 1/4 the gap that is left at the end (the angle error being accumulative).

Regards from Perth

Derek

Originally Posted by Interwood

Hi Sprog,
I would appreciate the extra details on cutting picture frames with the Triton please.
Interwood

OK, give me a couple of days, just a bit busy at the moment.

If you have a slight gap in your mitres because the angles are not quite right, there IS a simple solution that doesn't involve endless checking with protractors or fiddling with shooting boards.

First, glue up or clamp the frame. Next, take a thin kerf saw and cut along the mitre joint line (the kerf needs to be slightly wider than the gap. The two sides of the cut must now match up ! ( Assuming your saw blade is the same thickness throughout it's length). A thin Kerf Japanese saw is good for this.

I realize that a number of you are more expertianced than I, however I fail to see the point in buying expensive machinery and then having to admit defeat and tidy up with a hand plane and a shooting board. Reset your machinery and practice untill you can cut a mitre. Make sure that the machine is cutting straight and the fences and squares are accurate get help to set the machine correctly if required. Practice.

Frank

Clint,
I use a sled with a right angled fence bisected by the saw blade, mark accurately but cut the frame bits just a bit oversize (but not more than half a saw blade width) Then hold the two pieces against the fence so that the marked lines coincide with the blade cut in the sled, run the whole lot through the saw and, bingo, a perfect mitre! It doesn't matter if the sled is a bit sloppy in the guides as 1 or 2 degrees one way or the other won't make much error as per Simon's drawing. I have a similar sled I use on the bandsaw which gives a smoother cut than the circular saw.
Graeme

Originally Posted by Interwood

Hi Sprog,
I would appreciate the extra details on cutting picture frames with the Triton please.
Interwood

As requested, I have posted the details in the Triton forum.

While the details are specifically for the Triton, the same method can be employed quite easily on a table saw.

http://www.woodworkforums.ubeaut.com...9436#post89436