# Spacing question



## twisted bit (Dec 3, 2009)

Well I thought that I would pose this question to those that have done this a time or two If using a 1/2" o.d. collet with a 1/4" bit for making the mortise the spacing on the pattern will change as follows. The piece that will be put in the jig is 20" long and will have eight 1 3/8" wide tenons across this distance starting 1" from the edge so that means that I need to a 1/4" to the 1 3/8" making it 1 5/8" that the length of the slot in the template becomes. I would also be correct if the spacing between each groove becomes 3/4" from what was a 1" space this will then give me a 1" spacing between tenons and the tenons will be their original size on the final product Let me know if I am missing anything or if I got it right really don't like making more shaving than necessary
Jerry


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## jschaben (Jun 21, 2009)

twisted bit said:


> Well I thought that I would pose this question to those that have done this a time or two If using a 1/2" o.d. collet with a 1/4" bit for making the mortise the spacing on the pattern will change as follows. The piece that will be put in the jig is 20" long and will have eight 1 3/8" wide tenons across this distance starting 1" from the edge so that means that I need to a 1/4" to the 1 3/8" making it 1 5/8" that the length of the slot in the template becomes. I would also be correct if the spacing between each groove becomes 3/4" from what was a 1" space this will then give me a 1" spacing between tenons and the tenons will be their original size on the final product Let me know if I am missing anything or if I got it right really don't like making more shaving than necessary
> Jerry


Hi Jerry, welcome to the forums. 
If I read your post right, you are wanting a series of 1-3/8" x 3/4" mortices spaced 1" apart, using a 1/2" guide bushing and 1/4" bit?
I think you are right, the mortice openings in your template will need to be 1-5/8" x 1" and spaced 3/4" apart. 
Just an observation, those numbers also would work with a 3/4" bushing and 1/2" bit which I would recommend. Lots easier to clean out the mortice.  Unless, that is you need the tighter radius in the corners.


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