I am having an issue where a hole i use for a press fit barrel hinge is coming out smaller than my fusion drawing. I have measured my bit and it is actual size (.25" bit measures .2495"). The holes come out almost .4mm too small. Working with walnut, cutting with two operations a bore, then 2d contour for finish pass. current solution is just oversize the fusion drawing, but would love to figure out why its doing this…
also im running centroid with the servo motors
Kind of dumb question - are you sure your barrel hinges are a consistent diameter? 0.4 mm is 0.016" which is not very much when working with wood. I have found, when making pockets for hardware that going 0.01-0.02" over the size of the metal makes for a nice drop in - a snug fit without having to pound anything.
We have checked that, and they are not perfect, but the variance there isnt enough to be a problem because once i size up the hole in fusion they go in… My main issue is when i caliper the hole i make in the wood it is smaller that what i have modelled in fusion
Do you know if this is general? If you cut out a part is it a different size than what you modeled in Fusion? I’m not a Fusion user and I just upgraded to the Centroid/Servo system two weeks ago. Sorry I can’t be more help. This sounds like a question for Eric or the Avid support team.
There are a lot of factors that can affect this. I talk a bit about tolerances in this video: https://youtu.be/ID2WLf2jn6A
If you are 0.016 too small, it is really an issue of 0.008 per cutting edge, which is quite a bit off. Maybe make sure your machine’s steps are calibrate right: IE: a 6" square cut will measure dead on 6"x6". If not, you need to calibrate your machine a bit.
FWIW, I talk about this in the video, but don’t change your model size; in your final toolpath set the stock to leave a negative amount to make a larger hole. I usually use -0.005 to -0.008 for wood to wood fits.
Have you checked Fusion for “stock to leave”? I run into this periodically. You can simply uncheck it to be sure it’s not intentionally leaving some “meat”. Seems unlikely since you’re doing two operations, but worth a 5 second check.