Before I post another WIP, I would like to share with you my way of cutting 45° frames.
To cut mitered frame that all the 4 corners will fit, we need 3 conditions:
1. every two opposite members must be exactly the same length.
2. The miters must be cut exactly at 45°.
3. The cuts must be at 90°.
The above conditions are for a perfect world but...not always the blade is at "dead" 90° and the sled is not always cutting "dead" 45°...
Another problem is, when the members are 4~5 feet (or more) long....we have to add a long fence, just to clamp the "stop" somewhere behind us and not only but, the stop must be wide at list as the member width and must be at 90° to the fence.
So, I tilted my head to the left (to concentrate all the IQ in one spot ) and:
Instead of messing up with angles and protractors, I'm using a big, dedicated triangle.
The cutting method is “Left” and “Right” to overcome any small deviations from 45° and 90°.
The "stop" (or "limiter") is positioned at the front and that eliminates the need for a long fence or any fence...
One important point....
I'm cutting the frame members to “final dimensions”, before cutting the 45°.
As you will see on the pictures, the triangle vertex is positioned at the center of the kerf, which means that, every cut will shorten the member by ½ a kerf width and, because we are cutting each member from both sides, each member will be shortened by 1 kerf width.
In simple words...if you are using an 1/8" kerf blade, add 1/8" to the “final dimension” of each member to get your planned dimensions after cutting.
On the last two pics, you can see the latest version of the sled.
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