Centroid Community CNC Support Forum

Hi Everyone,

Newly converted Shapeoko 5 Pro to Acorn here! I am really just starting to get into the CNC12 software and things have been running great. I was machining a plate today and noticed some less than smooth movement of the machine on a bore operation. It almost looked a little "jerky" as the machine was boring a very small (2.5mm) hole. After the operation was complete and I looked at the hole, I could tell they were not nice and round. I am not sure how to describe this other than the hole just looks lumpy. I cant tell if its oblong in any certain axis or not. I have Oldham style ball screw couplers and the X and Y axis ball screws are 16/20 pitch. Everything seems mechanically sound and runs great but the holes are a big issue. Hopefully someone here can shed some light on what might be happening. In the picture, how I am holding the part is how is was oriented in the machine. Thank you!

There could be several reasons for this. Please post a current report from your machine so we can see how it's setup. The first two that come to mind are It could be a mechanical issue or your overall turns ratio is not setup correct. There are several more reasons but a report would help narrow it down. Also, start a Google photo album of your machine and share the link here so we can see what you are working with.

Thank you Shawn. I was able to get back to the machine today and dialed in the overall turns ratio even tighter of a 12" travel on X and Y. 4" on Z. All of which were repeating within .0005". I checked all of the anti-backlash couplers (Oldham style Sewa couplers) and they were all tight. None of the ball crews and nuts had any amount of slop or play. I have been using this machine with the controller it came with for the past 9 months and have never seen this problem so I am wondering if I dont have some software parameter set correctly. Here is a fresh report from today and a link to my OneDrive folder with pictures and video. Could it be the Fusion Post processor?

https://aerologicsolutions-my.sharepoin ... A?e=EOlgWW

Could it be the Fusion Post processor?

Possibly. What do the circles look like, when you zoom in close using F8/Graph, F7/Zoom In?

Post a copy of the offending CNC program. The only CNC file in your above sharepoint folder appears to be something entirely different.

Here is a picture from Fusion and I will get you a picture of the CNC12 display today. Also, here is the NC file for that particular project. The one I uploaded into the OneDrive folder was the one running in the pictures and videos in the folder. It seems to do this on all circular operations.

G-Code is ok.

I suppose the feedrate is too high for the stability of the machine.

Uwe

Thats the strange part. I've been running these feedrates and higher with the stock controller and it was fine. Now that I've switched to Centroid I am getting these weird movements. I can run adaptive toolpaths at 120IPM with no problems and its smooth as butter.

The test is to run those holes at 10% of the feedrate you previously used. If the holes turn out round, then it is a machine issue.

How could it be a machine issue if I have previously run this on a different controller with the same tooling and programs with zero issues? That makes no sense. This machine is not a new build, I have been running it since January and have never seen this issue until the controller swap.

Have you machined holes this size at the same feedrate with the same size cutter? Cutting 12" at 100" a minute, is quite a different thing than cuttind a 0.1" square at 100ipm.