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Posted: Wed Jul 14, 2010 3:05 pm
by SDSSmith
heathicus wrote:I'm not mathemagician, but I'm still lost... With the table tilted to 22.5 degrees, isn't it 22.5 degrees on one side of the blade, and 67.5 degrees on the other side of the blade?
The table is at 0 degrees and the blade angle to the table would measure 90 degrees on both sides of the blade. Tilt the table 22.5 degrees and the angle between the blade and the table would measure 112.5 degrees on one side and 67.5 degrees on the other. Both angles have to add up to 180 degrees not 90 degrees. Hope this helps.
Posted: Wed Jul 14, 2010 4:05 pm
by heathicus
SDSSmith wrote:The table is at 0 degrees and the blade angle to the table would measure 90 degrees on both sides of the blade. Tilt the table 22.5 degrees and the angle between the blade and the table would measure 112.5 degrees on one side and 67.5 degrees on the other. Both angles have to add up to 180 degrees not 90 degrees. Hope this helps.
I understand now. The table, in relation to its original 0 degree position would now be 22.5 on one side of the blade and 67.5 on the other side. But, that would result in a cut of 112.5 degrees on one side and 67.5 degrees on the other side.
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Posted: Wed Jul 14, 2010 4:38 pm
by SDSSmith
heathicus wrote:I understand now. The table, in relation to its original 0 degree position would now be 22.5 on one side of the blade and 67.5 on the other side. But, that would result in a cut of 112.5 degrees on one side and 67.5 degrees on the other side.
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You are correct if the piece you are cutting is laid flat on the table. But if it is 90 degrees to the table the geometry changes.......112.5 degrees minus 90 degrees yields the desired 22.5 degrees.
Posted: Wed Jul 14, 2010 5:23 pm
by dusty
What you depict in this picture is equivalent to cutting a single piece of wood with the table tilted to 22.5°. Now, discard the piece on the right and create a second piece identical to the piece on the left. Now when you mate the two pieces, you get a joint the positions the two pieces at 45° with respect to one another.
Posted: Wed Jul 14, 2010 6:00 pm
by SDSSmith
[quote="dusty"]What you depict in this picture is equivalent to cutting a single piece of wood with the table tilted to 22.5°]
I must not get it......
The only thing in Heath's picture that is 22.5 degrees is the table. The angles left on the cut edges of workpieces after using this set up are 67.5 degrees and 112.5 degrees (as depicted in Heath's picture). Maybe the heat is getting to me, but I would think it is hotter in Tucson.
Posted: Wed Jul 14, 2010 6:45 pm
by reible
Is this what we are trying to make?
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Ed
Posted: Wed Jul 14, 2010 6:50 pm
by SDSSmith
reible wrote:Is this what we are trying to make?
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Ed
I think that is what wdelliot is after, but only he can say for sure.]
Posted: Wed Jul 14, 2010 6:53 pm
by dusty
If so, then I understand why I am confused (and dead wrong).
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Posted: Wed Jul 14, 2010 10:12 pm
by JPG
reible wrote:Is this what we are trying to make?
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Ed
That is what I was thinking! Tilt the table 22.5 clockwise from horizontal. Cut the workpiece END laying it flat on the FENCE. Repeat second piece.
cutting 22.5 degree cut
Posted: Wed Jul 14, 2010 11:48 pm
by tenbears
If you are trying to make a 45 degree acute miter, split is 22.5 degree but the cut angle is 90 - 22.5 or 67.5 degrees. Make a jig to hold the wood at 45 degrees to the table, set the table angle to 22.5 degrees, rotated clockwise. Resulting cut with the jig and wood to the left of the blade is a 22.5 degree acute angle. I'd be extremely careful with this as the miter gauge may be very close to the blade. Far safer to do this on a miter saw, you will still need the jig to add the additional 45 degrees. You could also make a 67.5 degree jig and keep the wood to the right without rotating the SS table at all.