"Best" Extruder Replacement for UMO?

[coofercat 3]

I have an original, UMO (not the plus) - and the gnurled wheel is worn and so not very gnurled and not gripping the filament any longer. Getting a replacement is now expensive and slow (best I've found is something like 15 euro, international).

 

I'm wondering if I should instead upgrade the whole extruder to some other model? I see lots of people have done things along these lines, but I'm unclear which is the "best", or what the implications are.

 

Just to cover this off, I'm sure any replacement won't use the same mounting, and I'm fine with having to make some sort of custom mounting. I'm also fine with some custom firmware/calibration (I've long-since had to have a self-compiled firmware, so this isn't a problem).

 

Definition of "best" is of course subjective. I guess I'd like an extruder that has lots of grip, doesn't take much maintenance and is easy to disengage if you have to do a filament pull or swap or whatever. I'd love an out-of-filament detector, but this is completely optional. I think I'd prefer "skipping steps" rather than filament grinding, but again, I'll take whatever's on offer. The main thing is that I want some longevity so that I get another 10+ years before I have to change it ;-)

 

Any ideas what extruder to go for?

 

[coofercat 3]

Not sure about "best", but I decided to go in hard and bought a Bondtech QR (which is no where near the cheapest either!).

 

It's currently mounted by two cable ties, but so far seems to be working very nicely. Calibration was unexpected - I thought I'd just be able to use the datasheet quoted esteps, but seems that was too low (possibly because I have silentstep stepper drivers?).

[coofercat 3]

Finally mounted the QR by four hard drive silencers I had kicking about - the extruder now makes almost no noise (certainly not compared to the rest of the printer). The QR I bought was labelled as "Ultimaker 2", so doesn't have a way to fit to the UMO's sort of drop-in slot design. I drilled 2 holes and used two of the slot holes to mount the extruder.

 

One gotcha I had was that in the initial install, the extruder seemed to put electrical noise onto the temperature sensor. I tried everything - separating wires, twisting wires, messing with the fan, fiddling with bits and pieces, you name it. Nothing worked, so I thought I'd just rule out the extruder by unplugging it (it has a connector on the motor, so easy to do). With the extruder disconnected, suddenly the temperature readings were super-stable for the first time in hours. I plugged it back in, and it's still fine. Not sure what the problem was, but it's all sorted now.

 

The QR definitely has a lot of "pushing power", but it can (and does) slip if things don't go according to plan. It's pretty obvious when it does slip, which wasn't always the case with the original extruder. The filament entry on the QR is more defined, so I figure I could add a filament movement sensor to keep track of skips.