Odd issues with my right extruder

So I've never really used the right extruder.
Nozzle got blocked when I first had the machine, so it was completely removed for a while.
Then when I put it back I found the left had worn too short. So removed nozzle again until I had a replacement nozzle for the left extruder.

I actually put a 0.5m nozzle on righty. Then I got simplify3d and discovered that I couldn't get it to print with the right extruder at all.
Still haven't fixed that.

makerware doesn't have an issue - but no option to tell it I've got a 0.5mm nozzle.
So haven't been using righty much art all.

I did do some trolley tokens (nothing tall) with the right and it didn't seem to make much difference makerware not knowing that it was not a 0.4 nozzle.

So I've now got a 0.4mm nozzle for the right.


tried it last night with makerware and known models and filament. And it'll load and unload filament without any issues. It'll print the first few layers, without any problems. But when it starts to print much beyond about 5 mm it starts to lose filament.
No clicking sounds from the extruder, temps are fine, but the filament just gradually stops extruding.

Used different filaments, no difference. Everything works fine with the left extruder.

it's almost as if the right extruder loses power as the model gets taller. Nozzle isn't blocked, loads and unloads filament with no clicking or feed problems. filament comes down straight.
just won't print anything taller than a few mm.

I'm pretty much stumped at this point.

Thoughts please.

Can you swap left for right and see if the problem remains with the extruder or with the driver and wiring?

Yes, you have gunk in there...

Did you by any chance put the bronze in that one?

Guitar string, up the hole... only thing that I can suggest I know will work.

Came across this neat idea the other day for removing an impurity stuck in the nozzle: http://hydraraptor.blogspot.co.uk/20...e-cleaner.html

The last nozzle was fresh from the packet - and nope the bronzefill is fine and left head only. I literally haven't used the right head since I've had the machine. So this could well be an issue it's always had.
It's not blocked, the extruder does not click, it feeds through straight, smooth and at the correct speed when loading. It just doesn't print.

I'm going to try it again with a fresh 0.5 nozzle (got about half a dozen brand new ones). But I'm pretty certain it's not a blockage.

The same cheapo white pla I was trying to test works brilliantly from the left head. 13 a kg !
Going to order some other colours from the same supplier.
I'm also using a replacement nozzle on the left head - so I'm pretty sure the nozzles are good.

Aardvark, did you try pushing the filament through manually till it extrudes? If not - do try, and post results. You want to compare the force you have to push filament through to extrude between both nozzles. If it's identical on both, it's not clogged, and you have to check the tensioning spring on the motor.