Hey, Guys. If you're a new R2 builder you might be interested in this. I have an R1 that has made thousands of hours of successful prints. I recently nailed down a large printing contract and purchased two more FT5s, now the R2. After a week long build of both I began the testing and horror of horrors - both machines would make random moves during the print. I've been in CNC for 30 years and I've never had any machine move without specific instructions to do so from the G-Code. But now I've got two machines that will begin a print - stop and move in either x or y, sometimes to the stop, then move back to the print and continue. Of course there were missed moves in the interim, also, sometimes the extruder would shoot out excess plastic, and one time the Z actually moved the print upward into the head.
Of course I thought that I'd made a mistake in the wiring and began what turned out to be another week of hair pulling while I swapped out controllers, processors, stepper drivers, firmware, SD cards, G-code. All indications pointed to a a "communication" error of some type. But what? These machines were built EXACTLY like the successful R1. The only differences worth noting was the 24v system and the ACM material.
The company was mildly helpful at best, and eluded that there might be some "interference" possibly with the ribbon cables - shielding them might solve the problem. It didn't. Moving cables, wires, components, no appreciable change in confidence of the printer. Same SD cards and programs that worked on the R1 did not work on the R2.
I talked to everyone that might be helpful and when talking to a "radio" guy he suggested trying some "bead chokes" a few of which he had. I borrowed them, installed one on each end of the two ribbon cables and holy crap, it worked perfectly. I knew that the solution would be evident when we found it, but I never thought it would be so simple a solution.
I purchased an assortment of 50 from Amazon and placed chokes everywhere that might emit or receive errant emissions. Both of the new builds seem to be rock solid now.
FT allowed to me midway through the troubleshooting that they had indeed had customers with errant machines, but they had not solved the problem either.
So it appears the some build might be susceptible to this problem, for whatever reasons and I won't try to extrapolate on what those might be since the problem is reasonably easy to solve. The 24v system and the ACM seem to be at the heart of the issue IMO.
I've gone back and installed these on the R1 as well. The difference between a stable system and an unstable one is very small - I can't take chances with prints that take 8hours plus.
BTW - all of these results and issues were when printing from SD card, can't comment on printing from PC, I simply don't.
If you have any questions, please post and I'll help if I can.
All the best, Don