Hi Everyone! So, I just completed my upgrades of two additional milling heads on my workbee 1010! Works perfectly except that over 70% jog speed, the Z-axis motors start making a grinding sound as if the steps are skipping (I have the Z-axis current setting at max). I tried running at 100% jog speed while disconcerting motors sequentially for the 3 three heads, to have combinations of just one motor, then two (swapping to make sure any combination of two heads works properly), and then all three. So one and Two heads connected works perfectly all the way up to 100% jog speed. It's just with all three heads running at over 70% causes the noise, as if steps are being skipped or the motors are struggling? I tried the Z axis current setting in different ways and the noise appears on even two heads running if turned too low. So it seems to me that there isn't enough current ro run over 70% jog speed. So my question is (as I noticed open builds are now providing a three headed system), is what do I do to correct this. Is there a special Z-axis power splitter board I need to use, if any? Thanks so much to everyone, will post pics of my system and enclosure once I get this right and working as a production machine properly
Our system wires the motors in parallel, so nothing particularly interesting. You do have a BlackBox? If not - the BlackBox has decent drivers. You are going to be sharing current with the other motors, so you may need to dial around acceleration/max rate values in Grbl Settings to make it more reliable. But also make sure its not wiring related: docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation] - 3 of the 4 wires making contact on one of the motors for example.
Thanks Peter, yes, using the black box, not the X32, the previous black box version. Are the drivers on the X32 better (i.e. do they provide more current). So did you guys experience the same issues while road testing your new three head system, or could you run the Z-axis at full speed without problems? Don't think it's wiring as I've tried the system by having 1 then two then three heads connected. For the two heads connected, I tried pairs of each Z-axis in combination to see if it was wiring. Each combination of two heads operating worked perfectly. It was only three heads together that the problem happens, and only when running with a jog setting of 70% or above, so I think it's a current source issue...
As mentioned: Every machine is a little different, your current acceleration settings might even have been tuned a little to be more aggressive that stock profiles. Dialing down the acceleration and max rate a little 10-15% should help
Thanks for that, I did dial those down prior to reading this and it does seem to be ok, though maybe I'll dial them down more as there does seem to be some slippage in steps . Just as feedback, now that multiple heads on one machine is becoming a sort of norm, does open builds have any future plans on releasing a black box that has multiple Z axis drivers. Perhaps one that allows the individual Z-axis to be controlled both independently (for homing in on the work Zero) and synchronously, so each motor has plenty of current to drive at normal (single head) speeds?
