Print Failing Extruder Skipping?  

Re: Print Failing Extruder Skipping?

Hi, I have started to use my MK2S in March this year. I have been printing for about 6 months with minor issues I could always fix. Recently I ran into the same extruder skipping problem.

I also tried everything to the point where I replaced the entire extruder-hot-end-nozzle to a brand new/company assembled one.
The problem is still there, the material flows through the whole line without any issue when loading the filament but when I start the print soon or later it starts skipping.
I also ordered a new pulley but as it transfers the filament during load it does not seem to be the issue.

I am at the point to replace the extruder motor cable.

Could you please let me know where you purchased and how you replaced the extruder motor cable? Is that an easy replacement?

I appreciate your feedback. Many thanks

It "should" be an easy replacement, because it is a known and sort ofpredictable failure mode.
The cables (all of them) for the hot-end "should" be connected via a clip-on connector to the RAMBO and the hotend, so the entire lot can be replaced in 10 seconds when required.

For now, I have not replaced the cables, I only figured out what the problem is. I stiffened the cable connection at the hotend and started a new print, but it failed again. I was hoping I'd get away without replacing the cables for a bit longer, but no such luck.

My plan is to partially dismantle the extruder and the end of the cable loom at the hot end end, only just enough to take out the extruder motor cables and replace a short length of all 4 of them.
I will solder new cables pieces to the old ones.
The breakages are bound to be close to the rear end of the extruder, so I will cut the cables at the front where they come out of the extruder, solder on new cables maybe 200mm long, cover the soldered connection with shrink wrap, feed the cables through the partly disassembled extruder, solder them to the good part of the old cables (after sliding on shrink-wrap), and hope that the breakage is not actually at the RAMBO end....... 🙂

Re: Print Failing Extruder Skipping?

Thanks. It sounds to be a lot of DIY work but might be easier than to dismantle the whole cable harness.

I have ordered a new hobbed pulley gear. Once arrived I will give it a try and replace that first.
If problem persists I will replace the extruder motor cable.
Next idea is to replace the whole extruder motor, I have 3 additional ones from the multi color update package which I have not done yet...
I will keep you posted about my findings.
Thanks again 😀

Re: Print Failing Extruder Skipping?

I have changed my mind, I am taking the printer apart and I'm installing the MK2S update which I have had lying around for some time. I have already installed the improved cable management part of the upgrade, but now I'm installing the improved RAMBO cover and the rods and bearings and U-bolts.
.
And while I'm at it, I'll replace the motor cables, maybe with a 4-core musician cable. Is is very flexible, meant to be bent while walking around a stage with guitar or something like it.
I'll cut the wires at the motor, leaving enough to solder the new wires on, and do the same at the connector end for the Rambo board.