I'd like to build a crosscut sled from a plan. There are plans on Etsy, Ebay, etc. but I thought this would be the best place to find the right one for me.
The purpose of the box is prevent your thumbs, fingers, and hands from coming into contact with the blade. The blade often comes out of the rear fence as you complete the cut. If your body parts are in line with the slot, the blade may cut you as it comes out the sled. The box provides a cover for the blade and keeps your body parts from contacting it.So if I'm understanding this correctly, you still push with both hands along the rear backboard (rear being closest to you) with your thumbs toward the center (hence the need for a raise portion of that backboard) so that your thumbs do not dip down? Is that the purpose of the box? To prevent your thumbs from sliding down?
You're right to suggest taking some time thinking about the depth. I have one pretty big sled, and almost ALWAYS cut with the workpiece to the right of the blade--but there have been some circumstances that have required me to cut with it on the left, and I'm glad I didn't just make it so it totally favored one side or the other.Build it to your specs.
One thing I see often is very large, deep sleds. Think about your work, but you’re rarely going to cross cut anything wider than 12“ or so. I think 16“ is plenty deep enough. I make mine wider to the left of the blade. Remember they get heavier and harder to store the bigger they are.
You’ll build more than one. I recommend keeping it simple on the first one. 3 layers of 3/4 ply laminated makes a good fence. Clamp to a flat surface while glue dries. 😉