My MPCNC is probably over 100 cutting hours now and needs some love. It is not sliding smoothly, though it continues to run. Pink foam chunks build up on the core due to static as well as on the x and y tubes making the bearings roll rough during typical operation. I try to wipe it down and vacuum it all off good, but some times are better than others and this is my workhorse. I’m sure a good clean and periodic maintenance is in order as well as a complete retighten and replacing a few cracked bearing holders on the core (to be printed once the v4.1 is done) would be most beneficial. The core is loose now because if tightened, it binds, which lead to one motor failure and also to my question:
Does anyone have a recommended rework schedule or inspection list or PM task checklist or a recommended interval for this service to keep things running smooth on an MPCNC?
The only thing I have ever done is rotate the tubes when a flat spot shows up. Paste wax, or maybe running a grounding wire to your frame? I have milled a bunch of the pink stuff but I usually kinda clean as I go so I have not gotten to the point of build up.
A quick and dirty set of wipers might be worth a shot?
For foam chips and other electrostatic issues, I have had success with static guard spray (supposed to be used for laundry) it makes the chips easier to clean up
I periodically inspect the bearings, make sure that they all.still contact steel. I have one set of truck bearings that seem to want to loosen.
The Z lead screw needs lubrication and cleaning. Inspect for cleaning often, lubrication if lifting the Z axis seems to demand it.
Check for cracks in the core clamps and trucks.
Thst’s about it for mine. Been running a coulle years now. I should have put a meter on it…
I have run the thing all day on a saturday with minimal cleaning between jobs for probably a true 6 hours of run time between swapping parts and tool changes. That is when it builds up. I’m nearby, but not continuously wiping it off… dust collection would probably help this a great deal, but it is just foam and cleans up pretty quick after the fact.
Based on your suggestions, I think we have this list so far:
keep clean after every use with vacuum / brush parts that don’t vacuum well.
Inspect for -
a. flat spots on the bearing surfaces
b. cracks on trucks and bearing mounts / core clamps
clean and lubricate z screw
check bearings for travel contact
verify end stops have not moved
Is there ever a time to resquare the core other than when replacing components?
Only if I notice a non-square cut…Previously I had always just built new versions of them before they needed any sort of maintenance. Seems we might have hit a whole new era of the MPCNC.
This is an old thread, but I just found something RE: stepper failure. So far I think I’m the only one claiming to have had a bad stepper. I just discovered that I caused this and wanted to call it out as something to be careful of - maybe you all already know this.
The point: take care to mount your idlers with a space between the idler and the motor housing or it will rub maybe even just a little and sometimes skip steps.
The steppers I’ve been purchasing and using for the MPCNC whether from Ryan or from aliexpress have a short keyed area on the shaft and the pulleys mounted to it are screwed in closer to the motor and don’t mount onto that flat part. I have had two different motors have a pulsing easy/hard rotary “drag” and I was convinced the motors were somehow bad. On my MPCNC it has been two motors (one after the other) in the same position have the same problem. It manifests as cyclic resistance when moving the gantry in the Y direction. I replaced the trucks, the bearings, the belt. Recently I disconnected the belt on that motor and the gantry moves freely. I pulled the motor and it spins with that cyclic difficulty. After removing the idler and spacing, no more issues.
This issue has led me to trash a perfectly good motor and almost a second one. Maybe my errors can help someone else.