4-way miter

Rennie Heuer

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I'm building a new cross for our church and want to have the middle meet in a 4-way miter (is that the right term?) :huh:

The mitered pieces are 5" wide pieces of 3/4" ply. Do any of you have experience in cutting a joint like this? Can you offer any pointers (no pun intended :rofl:)
Cross.jpg
 
For strength I would use a 'plus' shaped spline (kinda like a floating tenon) or even easier, a 'plus' shaped piece of hardboard laminated to the back at the crossing point(?).
 
I should have been more precise in my description. The picture does not show but this is actually a three sided box that will slip over the existing cross.

The four sided miter is only the front piece the sides will be 5 inches deep and pocket hole screwed into the front pieces. These will butt joint at the inside corners and be screwed together. I have no fear about the strength once it is all assembled.

I really thought the four sided miter would add some visual interest to an otherwise simple design.
 
6e7a4a9y.jpg
success!

I must have slept through that part of my high school geometry but it seems that if I use a stop on the miter gauge set at a 45° angle the point will always be dead center. So, as long as I have faith in the setting on the miter gauge things work out.
 
if you mark the short point of the miter and set your stop to that dimension then as you said, cut, flip, cut should do it. Run a test set first but I think your spot on
 
I should have been more precise in my description. The picture does not show but this is actually a three sided box that will slip over the existing cross.

The four sided miter is only the front piece the sides will be 5 inches deep and pocket hole screwed into the front pieces. These will butt joint at the inside corners and be screwed together. I have no fear about the strength once it is all assembled.

I really thought the four sided miter would add some visual interest to an otherwise simple design.

Doh! Yes, yes, I agree. The points coming together look very nice ;-)
 
Looks like you have it pretty much dialed in, but I thought I'd throw another look into the mix just because I thought it looked cool. This cross was designed for a friend, but in the spirit of true procrastination, and because I'm not sure how to cut the joint, has not been built yet. Kind of a fancy half lap. It would scale up nicely.
CROSS.jpgCROSS-3 (Medium).jpgCROSS-2.jpg
 
Ted, I like that approach. Looks pretty straightforward to cut (to me). Might need a little chisel cleanup, but doesn't seem that tricky.
 
Ted, I like the design, both in terms of its appearance, the inherent strength of the joinery. However, guess I'm going to show my inexperience here as that doesn't look like it's "straight forward" to cut to me. With the diagonal surfaces on the same planes, I think that would rule out a table saw; a band saw would leave a rough finish; so I'm guessing that would leave a router with some tricky templates to control angles & depth of cut. So, how would you go about cutting this, aside from a fair amount of chisel work?
 
Al, here's how I would do the cut, all on a table saw with an accurate miter gauge. The first two cuts would be with a regular blade, and the last one one be a dado blade (or even multiple passes with a regular blade).

Cross%20Miter.jpg


The process would be essentially the same on the other piece of the cross, too, just done on the opposite side of the beveled board.
 
Vaughn's solution looks good. Another way would be to make the X cut with a mitre box and hand saw and then clamp the piece on a flat surface between a couple of pieces of 3/4" mdf and free hand rout the triangles with a small router and flat bottomed bit.
 
What "threw" me was that I assumed the diagonal surfaces were on the same plane as I mentioned above. Seeing the TS blade cutting across the member to establish the diagonal surfaces now tells me they are on parallel planes separated by the thickness of the blade. Had they been on the same plane, I visualized only a partial cut, as the radius of the blade would prevent a full length of cut requiring chisel work to finish the diagonal surface. Oh well, thanks for clearing that up.
 
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