Actual Hole Size Not the Same as Specified - V-Carve

So I thought I’d make a tray with a bunch of 1/4" (6.35mm) holes to keep the growing army of bits in formation.

Bit Used = 5mm Down Cut
Tool Path Cut Type Used = Pocket
Job Format = mm
Tool Path Format on Save - Onefinity mm
Hole Size Specified in V-Carve = 6.35mm
Hole Size Produced = 6.05

Had to go back and forth between V-Carve and Onfinity Control Panel adding a half mm at a time until I reached 6.65mm and the shanks fit snugly. FWIW, and I don’t think this is related, I have set the ball screws to 16 revs instead of 10. Did that when I found the Journeyman was shipped with WW soft limits on X instead of JM soft limits. Also, the holes are perfectly round - no ovals. "Dear, dear, what can the matter be?

And while we’re at it, does anyone know how to do a group or batch edit on a number of vectors? There are 66 holes on the grid I was working on today. I tried selecting all of them and pressing the space bar to get into the editing area. Upon pressing the space bar (or the shift key) everything became deselected. Tried grouping them all - same result. Choice before me without the answer at hand was 66 separate edits or delete all of the vectors and start over. I chose B. Thank God for Array Copy.


Also, test your machine to see how accurate the movements are.

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Thank You! 20 Characters.

Check your 5mm bit with a micrometer and see if it is really 5mm.

Micrometer reads 5mm on the nose. On a test piece with one 5mm hole drilled/pecked instead of pocketed, a 5mm shelf pin fits perfectly. I’ll try Josh’s suggestion as soon as the the rulers arrive. I wonder, though, how a minor difference over a fair distance can result in a significant difference within a small area.

I work with veneered sheets a lot, and an upcut bit as a drill produces an unsatisfactory finish. A downcut bit as a drill produces an excellent finish but creates the possibility of overheating the bit or creating a fire in the material. For this piece which calls for 1/4" holes, using a slightly smaller downcut (5mm) in a pocket w/ spiral ramp seems to be the best of both worlds. I had been counting on CNC for the accuracy needed for this operation. I’m sure this accuracy is there - I just need to find out how to achieve it. If I’ve missed something and I’m botching it, that’s on me and I’ll take my lumps. If it’s the Onefinity, I hope the answer is out there; and; I wish it had shipped well enough calibrated to not cause this fault in accuracy.

Jim, I read somewhere in forums that there is a compression bit available that has .125 downcut then upcut the remainder of the bit. I believe this will give you the results you are looking for with veneer. Hope this helps!

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