Slightly eccentric feeder motor shaft

[rotorhead 1]

I've done an awful lot of fault checking, and upgrading on my UM2 recently to try and get it to print just right (the low friction spool holder, the Olsson block, door on the front for ABS, dust filter and a new filament feeder) and so have inevitably spent quite a lot of time getting to know my printer and have noticed that the feeder motor shaft is slightly eccentric! Initially I thought it looked like that simply due to the flat on the shaft but when changing the feeder I had chance to check it and it's definitely not rotating only on its own axis. Over 0.5mm ellipse, maybe up to 1mm, it's difficult to measure exactly.

I have had some problems in the past with feeder motor skipping on PLA and grinding on ABS and was just wondering if this change in pressure from the motor could be the problem, or will the spring in the feeder adsorb this change in pressure from the eccentric motor?

Thank all again in advance!

[gr5 2,270]

I don't know the answer but it doesn't sound serious to me. You can buy various knobbed sleeves for just a few pounds. google "reprap mk8"

[rotorhead 1]

I don't know the answer but it doesn't sound serious to me.  You can buy various knobbed sleeves for just a few pounds.  google "reprap mk8"

 

Excellent. another upgrade to get on with :-)

although the grub screw holding the stock one onto the motor must be the cheapest that UM could find, none of my hex keys will grab it - and no they are not knackered. An upgrade for a later time then.

[IRobertI 521]

The spring should be able to accommodate that variation I'm sure.

As for the screw. I never use allen/hex keys on anything small like that. It's just crap. Try using torx instead, it grabs much better and doesn't strip screws the moment you touch them.

I wish the world would move on from the slot/"star"(phillips etc)/hex formats and go with torx instead. I've never, ever, had a problem with those.