Thread: Huge Gap on 4th corner

Manny, welcome. There might be a minimum posts threshold before you can post pictures-if you added some they aren’t visible.

Yes though, in answer to your question. A frame needs to be mitred at 45.0° Thats why picture framers use Lion mitre trimmers (or the cheap copy). As you have discovered, any error gets four times more visible in a frame. The more corners, the worse the result.

There's very little room for error with mitres because the error compounds at each cut, so your 0.5-0.7 degrees x 8 cuts is 4-5.6 degrees out by the time you get to the end.

Whenever I was doing mitres on the panel saw at work and had to angle the fence instead of the blade, I'd do test cuts with scrap and tweak the angle until it was right.

First welcome to the forum.
As well as the angles being just right opposite sides must be exactly the same length. A stop block on your jig can ensure this part is right.
Regards
John

Yes. My picture did not get posted.

elanjacobs, I believe you. I went to check the angle on my gap and its 86.3~ which is the add on of the rest corners. I am going to make my jig more solid. I believe its the play making me be off a few degrees.

Thank you all for such a fast response!
Great welcome!

There is a solution.

I am using a sliding compound miter saw which makes things a bit different.
First, set the miter at 45°.
This setting should not be changed until all 4 corners have been cut. (i.e. 8 cuts)
Make the first cut using the fence to the left of the blade. Make the cut for the mating piece using the fence to the right of the blade.
When making the second cut the opposite side of the piece has to be against the fence. This method probably can be adapted to setting the table saw miter gauge to 45° and using the same technique.

On the compound miter saw:
NO CROSS ARM CUTTING OPERATIONS

Welcome to the forum

There is also another solution the Segeasy Sled by Jerry Bennett - wedgiesledplan1.pdf (segeasy.com) Seg-Easy Solutions (segeasy.com) The video webpage has a clip on making the sled.

It works for all angles - however the material used to make the sled fences must be jointed & thicknessed with parallel & square faces. Same applies in some applications where the stock is flipped the work piece must also be jointed & thicknessed with parallel faces.