U2+ Nozzles very hard to change

[RancherBob 0]

Hi All, we just got this thing a few weeks ago and now the nozzles are unchangeable almost.

Extremely hard to thread on and off.

I don't see the threads inside the machine with plastic on them, looks clean.  I tried some acetone on a q-tip.  Looked clean.  Nozzles are clean - I atomic clean them when I swap.

I don't see any damage to the nozzles or the internal threads, meaning I don't think there was any cross threading here.

If there is damage its extremely minute.

Just curious if anyone has experienced this and if the part of the print head that accepts the nozzle is changeable ie: the heating part or if I need a new print head if the threads are toast.

It seemed pretty difficult to change the nozzles (hard to turn) from the beginning.  The little wrench they send is a total joke.

Thanks

[RancherBob 0]

I guess a tiny bit of thread on the Olsson block is buggered.

Not sure how that happened 4 threads in but we will have to replace it.

Maybe I can tap it out.

M6 pitch?

Bueller?

 

 

[RancherBob 0]

Well we tapped her out and now screws great and I printed a bowden tube clip holder from Tough PLA at .25mm nozzle worked great.

Thanks!

 

[Torgeir 289]

Hi RancherBob,

 

Welcome in here, most people observe that some of the filament over time "leak" into the threads and somehow lock the nozzle likes thread lock is used -that's impossible to open in the normal way..

So, what we do is to preheat the nozzle (from maintenance menu - select advanced - then nozzle heating) up to the printing temperature of the last used filament. Now, it's very easy to replace the nozzle.. 

Also, I'm using copper pasta in between the threads - nozzle to heat body (only threads her - no spill inside body!!!), this improve the thermal conductivity between the nozzle and the heat block very much,-and also works a thread "seal" and anti size compound!

 

Thanks

 

Torgeir.

Edited March 12, 2019 by Torgeir

[RancherBob 0]

HI Torgeir and thanks for the welcome.

I'll make sure to change the head at 150c? That was what I was told.

I have been changing hot over 200c.

I'll try and look into this 'Copper pasta' sounds great!🤩

Edited March 12, 2019 by RancherBob