Ok, this is driving me NUTS! It happens randomly on different projects. What am I doing wrong? The detail pass drops below every other depth! Why!?!??
Using 1/4" ryobi downcut bit for rough pass and inventables 1/2" 60º Vbit for detail pass. Thanks in advance for any advice as to what I’m doing or, not doing that’s causing this…
Most V-bits have a small flat spot on the tip (may be very minute and not really apparent) => if you zero Z it will ride physically lower than anticipated => carving a smidge wider than what was calculated. This create a “dog bone” effect on sharp corners.
When you did your bit change did you do your zeroing in the same spot for the roughing and detail pass? AND how thick is the material you started out with?
Like @SteveMoloney asked, you MUST re-zero your Z axis after a bit change.
When you use a down spiral its cutting action causes the bit to push away from the bottom of the work piece. If you have any flex in your machine or work piece, this could cause the bottom of your rough cut to be not as deep as it nominally would be.
You should perhaps run some experiments with sample sections of your larger work. You could try a straight flute or an up cut and see if that makes a difference.
Harry that makes sense. I have another 1/4" bit (not downcut) I’ll try the carve with and see how it goes. Thanks for the replies so far Guys…