adjusting tensioner on MK8 (I think!) extruder

Hi,

I'm having some problems with my extruder, and after rummaging through a number of how-tos and FAQs, and helpful advice on this forum (thanks audacioustuddle and msaeger!), I've calibrated my extruder; checked the extruder stepper trim-pot (reading a bit high at 0.82V but the stepper is only mildly warm to the touch when running, and has never cut out so I figured it's OK); I've tried various heat settings, and I've concluded I think I have an improperly adjusted tensioner in my extruder. It still misfeeds quite regularly (clunks after almost every retraction), even at a quite-high 210 degrees.

I got a cheap Chinese prusa i3 copy, and my extruder looks like this:



From the very vague documentation that came with it, I think it's an MK8, but I can't find out anything else about it. I've looked at various youtube videos, and I can't find any that look exactly like mine.

There is only one socket that I can see (on the side of the lowest part of the extruder, it looks like an allen-key) to adjust it. Can anyone confirm if this is in fact the tensioner adjuster? I don't want to start messing around with it if it's not, I'm afraid of screwing up something else.... Or am I looking in the wrong place for the tensioner?

I have one like this. It is a Makerbot 2 or 2x knockoff. There is no tension adjustment. I believe even the genuine Makerbot 2 is considered a flawed design. They have upgrade kits for them. You can get one from Makerbot. Their page is being uncooperative right now, but search for "Rep2 Extruder Upgrade Complete Kit" on their site (www.makerbot.com").

You can also get an aluminum one from ebay like this:

[www.ebay.com]

that's brilliant, thanks hoxsiew. At least I know I'm not going completely mad... The ebay thing looks like an ideal replacement, thanks for the link.

update: for about the same price on ebay as the rep2 extruder upgrade kit, I can get a geared Greg's wade extruder.

http://www.ebay.co.uk/itm/361277431915

It seems I can just swap out the entire extruder assembly on my printer, and fit the stepper to the new one. Has any one tried this? Does anyone know if these geared extruders are any better than the rep2 extruder upgrade I would otherwise go for? (ie, this one: http://www.ebay.co.uk/itm/252183877442 )

Edited 1 time(s). Last edit at 02/09/2016 04:20PM by johngill1971.

Second link: looked very overpriced: Just to compare: [www.aliexpress.com] --> it's also from china like the ebay one.
wade extruder: Why do you don't print it out yourself?
---> [www.thingiverse.com]

Edited 2 time(s). Last edit at 02/10/2016 09:20AM by madias.

I'm thinking buy the BQ Unibody extruder. someone could confirm it works well or I go to the mk8?