I am having a serious issue with my Shapeoko XL Pro. Last week I was churning though oak mancala board construction with no problem. Then I took some time to cut pieces for a jewelry box out of cedar. Now I am trying to get back to doing more mancala boards (building inventory) and this is happening!! Note that the rough in cut works fine. I was having no problem with this last week. I have triple checked that the board is locked down tight and not wiggling.
One note: the first circle that gets the finish cut looks generally fine in every case. It gets progressively worse after that.
Updated to include the files. Using #201 1/4 End Mill for rough pass and #202 1/4" Ball Mill for finishing. I was using the #102 1/8 ball mill at first, but there was no advantage of that over the 1/4" for this project…
EDIT: I have uploaded a short video of some of the rough-in. Overall, it feels “sticky” and at around the 50 second mark, you can see how it completely miscalculates the x axis for about three passes before correcting. There’s indications through out the piece of it doing this.
Another Edit: I have captured the detailing pass weirdness. It is super odd. At this point, I am wondering if I need to just delete the toolpaths and recreate.
I only did the 201 because that’s what all the training videos I had seen suggested. I simply haven’t tried using the 202 for a rough in pass, but I probably should since that would save me a tool change.
I didn’t have this difficulty on softer wood. I also didn’t have this difficulty on oak last week. Only two things have changed since my last successful run:
I was using oak from Lowes and now I am using oak from Ocooch.
I spent a few hours cutting some cedar and acrylic, but those were using different bits and I have cleaned the machine since then. Reasonably well, I think.
The speed settings were not changed from when I was testing on Pine, so I’ll do a test run with the feed and plunge rates in that picture. I changed the step over to 0.016 in order to get a clean and smooth bowl since it is very challenging to sand that shape, especially in hard wood.
I believe I discovered my issue. Both of the y belts and the x belt were sloppy loose. I guess they have stretched a little since I first assembled the machine. I tightened then back up to spec and did a test circle which came out brilliant. So now to test a full up mancala board.
Also, thank you @WillAdams for the suggestion about doing the rough cut with the Ball End mill. It just improved the quality of the bowl even more!
