Hi all, So about a month ago I purchased the blackbox to install in my work bee 750 x 500. Everything went smooth. Tested all axis and everything worked fine. I started a carve and it did about an hour of the roughing pass without a problem. I then started the finishing pass, and I came back after about 2 hours to see it had burried the TBN bit down as far as Z would go and it kept trying to go lower, so it was skipping, actually trying to lift the machine up. I stopped the job, and restarted the finishing pass, this time it did the same thing, but only within 20 minutes. I can manually raise and lower the Z axis without issues. PreviouslyI had a UNO setup with external TB6500 drivers, so I thought I'd upgrade. Anyone had this issueorknows what's going on? Cheers John
docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation] check your motor wiring for intermittently loose connections
1) sure the endmill isnt pulling out of the collet (6mm bit in a 1/4" collet for example) causing a mechanical crash 2) check that the Z Axis drive components are mechanically tight (shaft coupler not slipping on motor shaft or leadscrew) - more load while cutting compared to jogging.
endmill is fine, 4mm shaft with a 4mm collet. Checked coupler, leadscrews, lubricated, clean, honestly everything looks good. Only started doing it as soon as I swapped to the black box. I have NEVER had this issue before. Could it be a faulty board in the blackbox?
maybe turn up the current on Z? and turn down the acceleration. both will make it easier for it to raise Z without missing steps.
Not a typical symptom of a failed driver so I doubt it. Does it jog fine? Grbl settings (too high Z acceleration and Z max feedrates causing stalls?) appropriate?
It jogs fine. Z acceleration is 150. Z max is 500. If no good, any recommendations? Thank you very much for your persistence
NEMA 23 on all axis. Edit: https://www.cnc3d.com.au/product-page/nema23-stepper-motor-2-45n-m This one
Its a little higher inductance than our motors (lower inductance = better acceleration) but at least it does have 3.6v coils (good choice) You mention it Jogs fine, so the drivers, motors, etc is good. Wiring as well then, any chance something is tugging loose when it start working a Job
It jogs perfectly. No weird noises coming from motors, nothing like that. It all seems normal. Even when I'm carving, it all works fine, until all of a sudden Z gets burried in the work piece. See attached pic.
- Post the Gcode (although it happened at different spots) - Any USB extensions, or EMI that could be causing Serial data corruption?
GCode attached, but as you said, I doubt it as it's happening in different spots. I'm running a laptop, with a straight out USB cable, (no extensions) straight to the blackbox. I also, always put thegcode files to the laptop itself and have it read from the hard drive rather than a flash drive. Same environment as prior to upgrading to the blackbox. I have an air compressor that kicks in and out when it needs to top up its tank, but like I said, this was there before and it never gave me problems. It's on the other side of the shed (9 metres away from the cnc).
Selective Suspend disabled? docs:blackbox:install-windows-selective-suspend [OpenBuilds Documentation]
No no, not Power saving, the specific settings, USB Selective Suspend, refer the link above its a windows settings that can turn off the USB comms if the machine stands idle even with normal Power Saving set to not turn things off
I'llcheck it out andlet you know. I just had another go after upping the Z current up a tad, and dropping the accel down to 120. It did the same thing, about 40 minutes later.
Still no joy. I've just contacted my supplier and hopefully we'll figure it out with their engineers.
Just do share this thread's link with them too to avoid them making you check the things we already checked again too
Forgot to mention earlier but also just check docs:blackbox:faq-emi [OpenBuilds Documentation] (could be corrupting serial data)
So just to update, the issue has been resolved. After speaking with Makerstore (blackbox Aussie supplier), we discovered that somehow my Z axis was set to 1/2 microstepping. This alone did not fix the problem. It seems I need to use the openbuilds control software with the blackbox. I have since completed a 10 hour carve and has not missed a beat. Thanks to those that chimed in and helped me troubleshoot. Your time and effort was much appreciated.
Ahh didnt realize you were not using a known-good sender. What were you running by the way. Its not that you have to use CONTROL, any good Grbl 1.1 compatible host will do, but do check the reputation of the application, some tend to favour fancy features over stability
https://www.cnc3d.com.au/commander It's the software designed by the people that sell the machine I bought. Looks pretty simillar to me. I never would've thought that changing the software would fix the issue.
Never seen it before. Yeah writing a Serial Comms interface is actually very hard. CONTROLs serial backend has been in the works from my earlier days with LaserWeb (so since about 2016) - lots of improvements over many years adds up (; See gnea/grbl (we use the Character Counting queue for optimal performance) If its not done right the application can scramble the data (send wrong data), or fail to know where in the queue it is. Particularly scrambled data could result in your issues Say you want it to send G1 Z-20 then G1 X10. It messed up and drops a few characters. And now it sends G1 Z-20....(misses the G1 X)...10 which together looks like G1 Z-2010 (a very deep down crash on z results)
