Rich Schneider
01-02-2008, 8:03 AM
Okay, what is the best way to get accurate results when cutting compound miters? That's the question..the long winded problem I've encountered is explained below.
I'm working on a four sided base for a decorative cabinet and am a bit stumped as to what is going on exactly...the miters are compound...15 degrees by 45 degrees (the sides of the base slant inward at 15 degrees....to get the slant the top and bottom of the pieces are cut at 15 degrees and are parallel)...I initially was going to cut the 45s the same way I would for crown molding by standing the piece up on the miter saw with bottom up, top down and therefore slanting back at 15 degrees and simply cut the 45s...but for some reason I changed my mind and decided to do this on the table saw with the piece laying flat, the miter gage at 15 and the blade tilted at 45...this all worked great except for one thing which perplexes me and I don't quite understand what is happening yet....my 45s seem to be off by about 4 degrees total (I pretty sure the 15 is fine since the miter gap is parallel top to bottom)..I set the 45 angle using a Wixey digital gage, zero on the table, 45 on the blade (I know I should make test cuts and finesse the angle that way but I grew to trust the Wixey)...but the Wixey 45 isn't quite right for some reason...so I had second Wixey angle gage I had just got and checked with that one...45.2 so that seems okay...so then I took the piece over to my miter saw, set the miter saw at 45, checked it with an Incra 45, stood the piece up on the saw and then checked to see how the teeth lined up with the cut from the table saw...about 2 degrees off, exactly half the gap I was seeing when I put two pieces together which makes sense...so then I decided to shut down for the day until I've got this figured out.....
I'm working on a four sided base for a decorative cabinet and am a bit stumped as to what is going on exactly...the miters are compound...15 degrees by 45 degrees (the sides of the base slant inward at 15 degrees....to get the slant the top and bottom of the pieces are cut at 15 degrees and are parallel)...I initially was going to cut the 45s the same way I would for crown molding by standing the piece up on the miter saw with bottom up, top down and therefore slanting back at 15 degrees and simply cut the 45s...but for some reason I changed my mind and decided to do this on the table saw with the piece laying flat, the miter gage at 15 and the blade tilted at 45...this all worked great except for one thing which perplexes me and I don't quite understand what is happening yet....my 45s seem to be off by about 4 degrees total (I pretty sure the 15 is fine since the miter gap is parallel top to bottom)..I set the 45 angle using a Wixey digital gage, zero on the table, 45 on the blade (I know I should make test cuts and finesse the angle that way but I grew to trust the Wixey)...but the Wixey 45 isn't quite right for some reason...so I had second Wixey angle gage I had just got and checked with that one...45.2 so that seems okay...so then I took the piece over to my miter saw, set the miter saw at 45, checked it with an Incra 45, stood the piece up on the saw and then checked to see how the teeth lined up with the cut from the table saw...about 2 degrees off, exactly half the gap I was seeing when I put two pieces together which makes sense...so then I decided to shut down for the day until I've got this figured out.....