I keep seeing a similar thing happen. I’ll start a run and it seems to be going fine, but then the machine will “jump” as if it’s now working from a different origin. Here’s an example where, on the first layer, it was supposed to mill the inside and then the outside of a bowl. It did the inside perfectly, then jumped up about 2 inches and drew the outside from a different origin. You can see that after it made the outside pass, it started on the inside again from the new origin.
If it helps, I’m using Fusion to create the model and Easel to output the gcode. Machine is a Journeyman Pro.
I also found it helpful to do an air cut (no material). If the home position is the same after the cut you are good. I found that especially the profile toolpath does this, the buildbotics controller does not have enough computing power. Been there too many times. Maybe a software update could solve this.
Thank you, Tom. You may be right, or it’s at least a combination of things. I’ve been exporting STLs from Fusion and importing them into Easel just for slicing and I think that ends up producing a needlessly complicated path. The other time I’ve consistently had this problem was when trying to run topo maps. I finally took the plunge today to use Fusion’s built-in CAM with the Onefinity postprocessor. While being quite a bit more work than the “point and shoot” Easel approach, it gave me much more control over the algorithm and produced a more precise path (2 hours vs 7). I ran it with that output without issue. FWIW, I am on the latest firmware. Curious what software you’re using?
I’ve had better luck using gcode created through Fusion, but have still had a couple of times where it has done a “jump”. I hate to think I just can’t trust this expensive machine to follow instructions if they bypass some unknown level of complexity. In this case, I’ve carved the same model twice, in the same material, and it jumped on one of them, ruining the stock.
Is this unique to me? I’m still just a personal user, but I can’t imagine people are putting up with this, especially when utilizing it for profit.
The things I have to put up with for profit … don’t get me started!
Please take this in the kindly manner it is intended. Nothing is perfect.
Over 20 years in CNC programming I’ve learned to just learn the limitations of whatever I have available and just get on with it.
I started out on CAM software that was in the $10,000 range that would every now and then post out circles that went the wrong way (crop circles we called them - blamed it on aliens). Since it was after the post it did not show up in simulation. (this was before online viewers) For important things we simply had to cut in wax before we cut in steel.
The CAM software I use now is in the $20,000 range. It has 3 ways to mill undercut regions but only one of them work, and that only after hours of fiddling, begging and cursing. I have worked with the developers on this and they can’t get the other 2 cycles to work either, even though their literature still says all 3 cycles can do it.
I work with 2 CNC mills now that when new were in the $400,000 range. They will randomly stop when trying to process a circle and give an error. I simply restart the code again and it will sail past the same area without any error. I have had the tech guys down trying to find why - they can’t figure it out. It’s way past warranty so we simply have to live with it. Of course it’s better to have the machine just stop in it’s tracks rather than loose it’s position as is discussed in this thread, but I typcally try to have them run unattended over night. So I will often loose many hours of run time to this.
There are many more frustrations like this that are waiting for me every day. All I can do is develop the habit of double checking every little thing I know could cause problems so as to avoid most of them.
So if I have to check for too many nodes in my path I just make it a habit to check every single time. Once it becomes a habit then problem solved.
I know this won’t make anyone feel better - it’s just life as I see it.
My experience - I ran a plain stock Woodworker upgraded to the Journeyman as shipped to me, no drag chains, no extension cables, no modifications of any kind to max speed, acceleration, jerk etc on 1.0.8 then 1.0.9 for over 1500 hours in the first year I owned it and never experienced an issue with the machine having a mind of its own. I did run a spindle which was grounded, in turn grounding the frame of the machine which likely helped with potential ESD, my dust collection uses conductive hoses and steel ducting which is also grounded.
If you’re running anything that is modified from stock configuration I’d look closely at those first followed by potential ESD sources like dust collection. EMI or electrical noise from other machines/dust collection on the same circuit can be a potential source inconsistent results.
