I have a multi step process for cutting some coasters for my kids teachers.
cut a circular pocket which defines the outer boundary and provides a dam for epoxy
cut the shape in the middle with advanced vcarve
cut the text with regular vcarve
fill with black epoxy
level
more advanced vcarve and more epoxy and then flatten, contour and finish.
All are in the same main file but I enable/disable paths and save as different chunks.
1-3 could have been in a single chunk but due to time constraints I did two.
Steps 1&2 were in the same job. That included the advanced v carve and a cleanup pass for vcarve.
Step 3 was the v carve text which had a regular vcarve pass with a max depth of .210 (starting depth .095 due to the pocket). I added a cleanup pass using the same toolpath and only changing the max depth to .215 which if I understand the regular vcarve shouldn’t really matter anyway.
The picture only shows 2 coasters but there are 5 on the board spanning 26.25”. The first pass looked great but I stopped it during the second pass as soon as I could see that it looked like things shifted. I don’t know if it really did or if the depth change really made a diff. You can see the issue when comparing the name at the top of the left one and “Mrs.” at the top of the right to all the other text.
The cleanup pass on the eagles looked great but would have been harder to tell about any shift.
I thought about just living with the issue on these two, but I just can’t do it so I will have to recut those two but will skip that second pass on the text this time.
There is no way the material shifted. I have already removed it from the machine to start the epoxy so I can’t verify XY but I will load another piece of the same size stock and check there. I am using a square so it should be exact. Although, that small a difference may not be possible to detect.
Thanks.
I am pretty sure that there was no mechanical interference and there are no knots in this board.
I will check the wiring again. I did tighten the X belt some recently when I was adjusting the Y belts, but I did not find any specific guidance on the tension on X in the various guides/posts.
As for Feeds and Speeds, this is what I have in the “cleanup” pass. If anything, my feed it probably too low.
I know that the Depth per pass seems like a lot, but since the text is pretty small I knew it wouldn’t really cut that deep. The only thing different in the first pass which ran right before this was the max depth was set to .205, but like I said even that shouldn’t matter really in a standard V carve so I have no idea why I changed it.
After recutting the 2 that are messed up I may try some tests to see if I can isolate the issue.
Seems like running a simple V carve on the left of one board and then on the right and then coming back and forth a couple of times with the same cuts in the same spots may tell me if things are shifting. Of course if it is intermittent I could try that forever and not replicate.
Yep, I have read through that thread multiple times and ended up setting my Y axis belts to 57Hz on my Pro XXL but any info in there about X tension is not jumping out at me.
I did the diamond circle square test in a stable medium last week and I am not really sure how to interpret the results. Some of the differences make me think I have a bad measuring methodology or a crappy digital caliper. I have a really nice analog one and will try with that as well.
Dimensions/results seem pretty good — probably if you want to do better you would need to leave a roughing clearance, measure, then adjust the CAM file for the finishing pass.
Remember, when measuring you want the device being used for the measurement to be 10 times more accurate than the dimension to which you are trying to calibrate to arrive at.
