This is a really weird one and I have no idea where even to start to narrow things down.
On several occasions the x motor behaves the same way an open loop stepper behaves when it is overloaded. It just kind of chatters back and forth not going anywhere. BUT, in my case it does this for a fraction of a second and then carries right on and there is no evidence of any steps being lost.
This is in the relation to a finger joint as mentioned in another thread (don’t know how to link to the thread)
edit by mod Here is the link
This happens on the x axis, specifically when I am forming a round-over. There is virtually no load on the mill and it even happens when I cut a second time in the same path that was already cut (should be no load at that point).
This does not happen when there is any real load on the cutter.
I can only think that maybe the g-code actually commands this rapid back and forth with tiny tiny steps. I tried to look at the g-code but I have not been able to locate the point where this happens.
Has anyone experienced this sort of thing?
So far I have only looked at the text file of the g-code but maybe the consol section of gSender will give ne more of a clue.
Edit: The tool path is generated with Fusion and is sent to the Altmill via gSender.
I changed the tool path from a ramp to a plunge feed and the issue is no longer present so it’s obviously something that Fusion is doing. I still would like to know what is happening but gSender doesn’t really offer any features to single step or go back and forth.
I tried to change the feed speed with both the slider and the up/down button with no luck. I was hoping to slow things down to the point where it is doing the thing and then hit pause to examine the gcode.
Are there any simulators available that let you walk forwards/backwards one gcode line at a time?
@Jens Look an ncviewer.com. You can simulate the toolpath and jog it line by line if you like.
FYI: To add a link, simply open the thread that you want to link to, copy the URL from your browser address line. Then, open a new thread and paste that link into it.
@gwilki, thanks for both answers.
Ncviewer showed why things were happening. I have no idea why but fusion decided to do a very tight down spiral in three or four tiny sections in the tool path. Ncviewer allowed me to zoom right in (and I really had to magnify things) and see the problem areas. I could not see a reason for this spiralling but it certainly explained why there was this horrid noise. The mill did exactly what it was told to do.
@Jens I’m glad that ncviewer helped to diagnose the issue. I have no competence at all with fusion360, so I can’t help there.
I noticed that @NeilFerreri asked about why your fusion toolpath looked the way it did in your other topic. Maybe Neil will have some thoughts on this issue.
I am happy to have found out enough to explain why the mill was shaking around like it was having a fit - it was just following instructions. As to why Fusion decided to do what it did - I don’t think we will ever know (and that is ok)