Major under extrusion after MK3S upgrade
I had a MK3 that had a hotend thermistor failure, so support sent me a new thermistor and cartridge and shortly after arrived my MK3S upgrade kit (self printed parts). I performed the upgrade and swap of the thermistor/cartridge... assembly seemed to have gone fine, however aftewards I'm having significant issues with under extrusion (entire layers at times). X belt tension after assembly is 262, Y belt tension is 260. I have also flashed to the Mk3S 3.6 firmware and performed PID calibration @ 215.
Prior to the upgrade I had zero issues and had beautiful prints on the standard MK3 setup. My first test print after setup was a Benchy, where I had pitting all around the mast area and along the door frame.
My first thought was a clogged nozzle somehow, so I performed multiple cold pulls and they all came out intact and clean. I then tried a frog at 0.05 ultradetail and you can see massive spongy layers
Again I performed cold pulls and decided to try at 0.1 layer height to no change. You can see layer failures here
I'm really at a loss what to do here. The grub screw on the bondtech gear to the Extruder motor is tight and the gear is not slipping. The bondtech teeth for the filament path are perfectly in line and appear to extrude properly. I have tried various tension on the extruder idler door ranging from "barely screwed in" to "pretty dang tight". Both bearings were inside the idler gear during assembly and the idler gear is free spinning. The PTFE tube is properly oriented and firmly secured in the hotend. These were sliced with Slic3r PE 1.42 alpha 7 using prusa printer and Prusament PLA profile (prusa PLA for the silver benchy, rest were Galaxy Black).
Where do I go from here? I'm pretty upset since my prints previously were beautiful and I just wanted to do the upgrade to have a reliable filament sensor, but now my printer is practically unusable. One thing I noticed after printing is my extruder motor is very hot (not too hot to touch but still pretty hot), though I've found on a cursory google search that is normal.
Re: Major under extrusion after MK3S upgrade
I have removed the M221 if layer less than 0.075, 100, else, .95 thing that was in the start g-code at some suggestion that it might be causing the under extrusion, no joy. Mast here still fails
Re: Major under extrusion after MK3S upgrade
Did you try marking the filament at 95, 100, and 105mm from the top of the filament guide and commanding it to extrude 100mm of filament to see if there's slipping?
I read another post on here about the extruder idler shaft can slip out of position but that was on a mk3, I didn't think the mk3s can suffer from that issue?
I had an issue like that myself, my thermistor on the extruder had an intermittent open in one of the two leads. In certain locations, the extruder would cool down and slow/stop the extrusion until the temp came back up. I found it was only happening on the right side of the bed so I slid a small model all the way to the left in Slic3r and it printed fine. I used that as a workaround until I had time to swap out the thermistor.
Re: Major under extrusion after MK3S upgrade
Did you try marking the filament at 95, 100, and 105mm from the top of the filament guide and commanding it to extrude 100mm of filament to see if there's slipping?
I read another post on here about the extruder idler shaft can slip out of position but that was on a mk3, I didn't think the mk3s can suffer from that issue?
I had an issue like that myself, my thermistor on the extruder had an intermittent open in one of the two leads. In certain locations, the extruder would cool down and slow/stop the extrusion until the temp came back up. I found it was only happening on the right side of the bed so I slid a small model all the way to the left in Slic3r and it printed fine. I used that as a workaround until I had time to swap out the thermistor.
I've just tested and confirmed that commanding a 50mm movement of the extrusion motor feeds in exactly 50mm of filament, so dead on the money in terms of actual feed. I just tried another piece, a temp tower this time, and had similar results, all seem to be failing about the same spot:
The temp tower was 2 hours 35 into the print, the dragon head on the left was 4 hours 2 minutes before I caught it, the benchy completed at 3 hours 4 minutes. Someone suggested to me that it's seeming like heat creep causing a clog after extruding for a while, so I guess my next step is to replace the noctua fan
EDIT: For what it's worth, to try to alleviate potential heat creep until I can sort out a new fan solution to test, I printed at 205C with 25mm/s external perims instead of the 215/35mm standard. I also went 0.15 layer height benchy which got the print time down to 2 hours 5 minutes. In this configuration I had no under extrusion or jams and, aside from some ringing that I've always had, got one of the better Benchy's I've printed. It seems heat creep is definitely the issue here and probably exacerbated by the MK3S upgrade housing being unable to provide adequate cooling with the Noctua fan
Re: Major under extrusion after MK3S upgrade
When assembling the MK3S upgrade yesterday, I noticed that when putting the extruder motor and gear in, it is positioned so much towards the filament, that while feeding the filament in, the gear is so much "in the way" that the filament can bearly (or not at all) reach the PFTE tube. Without the extruder door, moving the filament up and down already takes way too much force (so loosening the extruder door has zero effect...)
Perhaps you have the same issue?
RE: Major under extrusion after MK3S upgrade
Hmmm, this thread just kind of stops...for those of us experiencing similar extrusion problems, how did you resolve your issue? Thanks!