So been working great for weeks now...but now today... Go to surface my board because I put a thicker one on and now i am getting endless stops mid job with the hard limit triggered. It sounds like EMI but I have had no issues up until today... I havent used the machine in a couple days, and nothing has changed other then it looks like the software updated but I doubt that would have anything to do with this. I have ferrites on all the endstop wires just before the controller. my VFD is the opposite end of the table from the controller. Even tried a new shielded USB cable and still dropping out... HELP pretty please lol
Are you running a dust extractor, and have you earthed the extractor hose? If not, run some bare copper wire along the inside and connect to mains earth at the vac end. Alex.
I am going to replace my cheap chinese endstops With the proper openbuilds ones with emi filters built in.
Well I’m not sure what fixed for sure but I am fairly certain Alex’s recommendation was it... first I tried turning off hard limits, soft limits and I ground the the conduit pipe the vacuum line was zip to. Started a surface job and it crapped out with an error 26... so I assumed that was related to Emi. Swapped back to my USB with a ferrite on each end, and then I stuck a bared copper wire up the vacuum tube about a foot and rounded it to the gantry plate that hold the spindle (spindle chassis is ground to mains ground) so I had continuity from wire to Ground... started another surface job and low and behold It finished. Needed to take a tiny bit more off so started and other one and it finished yay!!! Success... question is now can only turn on my limits again. Guess I could run and air cut as a test.
So all that testing was for naught if limits was not enabled. Grbl only checks for (real or false) limit hits when Hard Limits is enabled. Turn it on, then start testing EMi mitigation strategies. You mention spindle: VFD? Those things are EMI factories. See docs:blackbox:faq-emi [OpenBuilds Documentation] particularly the link in the last point of the VFD section is a detailed read
I needed to get my spoilboard surfaced so I can run some jobs tomorrow. So I didn’t care how it got done, just that it got done lol. Yes it’s a got a vfd box. I’ve had no issues with in the last few weeks that I have had the machine running then boom all of the sudden. Hard limit triggers. Replacement XTension end stops are on order. First thing tomorrow morning I will run a surfacing job with no bit and hard limits enabled with my fingers crossed
Probably will stop again. If you the other type, yes, they are quite a lot more susceptible. All good, just mentioning that the other things you did, had no bearing on the results. As they were effectively turned off at the time.
Homing sets machine zero Hard limits protects against crashes. Read the Grbl Wiki (all of it) at github.com/gnea/grbl/wiki
well yes I understand that... but as long as one is careful that the jobs will not crash, or not accidentally run the gantry in to the end stop, then really worse case scenario it could be left off. but I would like to have it all turned back on and functioning properly . Gonna go buy a small metal tool box to encase the vfd itself. That box should be mains grounded I would guess? and then hopefully once the endstops are swapped this will be done
I don't think that that is necessary. My VFD is mounted a little, not more, away from any other electronic and I use a shielded wire from it to the spindle and I have no problems with EMI. I had them and I had put a capacitor on each limit switch connection at the Nano board I used for the GRBL and since then no more EMI problems. BTW, the shielded wire has the shield connected to ground at the VFD only, not on the spindle.
Well ran 2 tests this morning both successful! YAY First Test - set up a surfacing job for my entire spoil board and air cut it with Vacuum off and spindle full speed. Finished without issue First Test - set up a surfacing job for my entire spoil board and air cut it with Vacuum ON and spindle full speed. Finished without issue Static must have been building up in the vacuum line and arcing to the Z axis triggering the end stop. Previously the jobs would fail at the latest about half way thru. and the job was at least an hour
Are you sure you Reset after enabling Hard Limits to ensure Grbl did boot up with the changed setting? (CONTROL does prompt you to Reset right after clicking Save)
So for fun, disconnected the software and I just unplugged everything to make sure it’s all reset. starting new test now
Looks good then Dust extraction is a known EMI source: See docs:blackbox:faq-emi [OpenBuilds Documentation]
Well was able to cut my first ACM box for a product I plan to offer. Much easier getting a good result with a flat spoilboard specially when 0.1 mm can make a big difference in the folds.
