I can't disassemble the extruder gear......Help!  

RE: I can't disassemble the extruder gear......Help!

The idler shaft pushes out through the ears, freeing the idler gear and bearings. The driven gear has a set screw on the motor shaft flat.

https://manual.prusa3d.com/Guide/5.+E-axis+assembly+(textile+sleeve)/822

RE: I can't disassemble the extruder gear......Help!

I know the installation guide; the problem is i can't unscrew the extruder motor pulley.

RE: I can't disassemble the extruder gear......Help!

i think  the factory loctites the screws on prebuilt machines. you may have to heat the gear to loosen the loctite

RE: I can't disassemble the extruder gear......Help!

the last way could be, if you can't properly remove the screw, to remove it with a small drill (1.5mm diameter = thread core diameter).

if you want, i could do this for you, because i have the nessecary equipment.

with best regards!

RE: I can't disassemble the extruder gear......Help!

Posted by: karl herbert.g

the last way could be, if you can't properly remove the screw, to remove it with a small drill (1.5mm diameter = thread core diameter).

if you want, i could do this for you, because i have the nessecary equipment.

with best regards!

Thanks for the availability, but I think we are a bit distant 🙂
However, I have a friend who has everything needs, but I would like to avoid such an extreme solution, even if it seems the only possible way.
I also tried a gear unlocker like the wd40, but nothing.
I will keep you updated on the situation, thanks to all those who intervened in the discussion.

RE: I can't disassemble the extruder gear......Help!

There are "easy out" tools that are designed to drill backwards, they catch the hex and sometime can pull the set screw without too much fuss.  The kits also include reverse drills (cut ccw) to help get purchase when the tool by itself isn't working.

If you think you've stripped the hex of the screw, drilling is the only option.  If you haven't stripped it, then heat is the best option to loosen it up - doesn't take a lot, just heat the gear. 

And, I know this sounds stupid, no insult intended, but it's happened before: be sure you are turning the hex key counter-clockwise to loosen.

RE: I can't disassemble the extruder gear......Help!

Victory! after much wd40 and various screwdriver with a insulating tape for more grip as trick , i win 🙂
But there are another problem.....the gear don't move seems to be glued :-(......
I don't think a Prusa technician could have made such a mistake during assemblyng.

RE: I can't disassemble the extruder gear......Help!

Sounds like they applied a bit too mush thread locker.  If it is glued, then you're back to heating the gear.  A soldering iron would work as a controllable heat source.  Apply heat near the set screw hole while levering the gear off the shaft.

RE: I can't disassemble the extruder gear......Help!

I removed the gear from the motor shaft using a lot of WD40.
This thing worries me; with that premise, how can I reassemble everything if the driven gear on the motor shaft will inserted with force? how can i adjust it accurately when i'll reassemble for the mk3s update? is this normal for you?

RE: I can't disassemble the extruder gear......Help!

It may take a little work but acetone on a paper towel should work for the shaft. The gear and screw I would just soak in acetone. Repeat until everything slides together easily and smoothly.

I would recommend loctite on the grub screw for final assembly but with caution so it doesn't go everywhere.

RE: I can't disassemble the extruder gear......Help!

this could be helpfull tools:

RE: I can't disassemble the extruder gear......Help!

make sure the grub screw is fully removed, then try running a 5mm drill through the motor shaft hole, with your fingers, that should clear the loctite without damaging the bore.

probably best to get some spare m3 x 2 grub screws, an use a new one, on reassembly

regards Joan