I’m writing this to hopefully help someone that has or is having the same issues I did when starting this project.
tl;dr
It was the stepper motor.
Backstory
So I started this project about a year ago. I had just gotten a 3d printer and I vowed to myself that I would never print “trinkets” with it. Naturally, I would pick one of the biggest 3d printer project out at the time. The MPCNC.
After printing it all out, which took a ton of time, I assembled it all with high hopes of cutting stuff as soon as I did a few runs with the pen and paper. Unfortunately, it didn’t go that way. After putting it together checking everything it would get this “buzzing” from my z axis stepper motor that sounded like it was jamming.
I took out everything made sure it was strait, level, lubed, etc. Nothing seemed to work. I sent different gcode and that still didn’t work. I probably spent a good 3 weeks trying to debug this thing. It got the best of me. I put it in the corner of the garage with the intent of throwing it up on ebay when I got around to it.
Fast forward ~10 months
For some reason or another I went out in the garage and saw it sitting in the corner and thought I can’t let this stupid thing beat me. I mean, there are 10s of new videos a week going up on youtube of people building this thing. I’m going to get this working.
So I started researching all of the potential issues that it could be. Since I had build it so long ago, I still had all of the -old- design. So I thought it had to be something with my printed middle parts that was throwing the whole thing out of alignment and causing this thing to jam up and the z stepper motor to skip. I found the the z nut lock was cracked and broken so I searched high and low to find it. Someone on this forum sent me a link to download it. (thanks Barry) So when I reprinted that and put it back on… same issue. F.
Next, I had some yellow PLA I wanted to get rid of (probably would have chosen some other color) so I started printing all of the new middle pieces. (BTW, the design of new middle is awesome.) This took a couple of days to get done, luckily I had the holiday to keep the printer running. Once I had all of the pieces assembled, I took it all apart and put on the new pieces…and same shit, it kept buzzing. W. T. Serious F. I was about to flip the table over. But the engineer in me, said “let’s get to work and debug this thing”.
So looking at all of the other threads I tried everything under the sun to try and figure out what was going on. I knew that it would kind of work when the stepper motor was moving at a slower speed, so I tried tweaking that. I did get it to a point where it would “kind of” work but something was still clearly wrong. I reflashed the firmware with Ryan’s latest. Still nothing.
Next, I re-took everything apart again, leveled, squared, tightened down everything.
- I lubed up threaded rod with white lithium
- Swapped out the stepper driver motor
- Checked the cabling
- Changed the power supply
- Checked to make sure the threaded rod wasn’t bent (nope)
- Re-did all of the belts…because i was grasping at straws here.
- went back and forth between an aluminum coupler I have and the pineapple printed coupler
At this point I was thinking about all of the parts that I still had on the machine from prior to printing the new parts. The only thing left was the stepper motor. In all fairness I did test this and it would spin, along with the fact that the likelihood of stepper motors actually failing is very low. I pulled it off to make sure I had all of the wires correct and I wasn’t using a 1/2 wound coil (these have 6 wires). It all looked good.
So I had some other 3d printer project parts laying around so I took a motor from there. (this was a different brand and smaller than the 5 I had on the machine already) I put this one on the z axis. And… holy shit it worked. It worked great actually. I did some speed testing with the motor when it was off of the machine but still hooked up and I could clearly see that it had issues with speed as it would buzz when sending a large travel distance. I’m guessing the specs for this motor can handle the higher demand from the z axis because the x and y work great.
I ordered a slightly bigger motor that I just finished putting on and it works great. (Amazon prime baby!)
Hindsight is 20/20 - but I hope this helps someone else in a similar situation as me save some time.