Tool Crash Problem Fixed
Tool Crash Problem Fixed
I have 1,248 hours on my 5 tool XL and have used 7.6 km of filament without any issues since I received it last November.... until today.
After starting a print, #4 tool failed to be picked and the display showed "TOOL CRASH."
After shutting down, I gently rocked the tool back and forth & front to back while it was parked and detected a lot of motion. All other tools felt secure.
About 2 weeks after I initially assembled the printer, I checked the torque on those screws that fasten the Nextruder docks to the long metal profile and they seemed tight.
Today I removed the honey-comb panel that covers the back of the areas where the Nextruder docks attach in order to provide easy access to the printed parts that have the holes for the screws.
The screw to #4 took 2 full turns to torque it down. I used pliers to grip the short end of the 2.5 mm hex wrench in order to apply adequate force.
Number 1 needed almost one full turn to get it tight.
So, I"m going to check those screws again after about another 500 hours. Apparently they vibrate loose.
I think the Prusa needs to re-engineer this part of the machine.. Only one small M3 screw seems too weak in this area.
Hope this helps others that might have this problem.
RE: Tool Crash Problem Fixed
Definitely seems like an odd choice of hardware/mount design for something as critical as this.
Mini+MK3S+XL 5 Tool
RE: Tool Crash Problem Fixed
1) purchase a set of quality hex tools with shaft length to get to these screws.
a good hardened steel tool set will allow you to torque the screws with more force before they strip.
2) use thread lock on these so they do not loosen from the plate inside the C channel.
3) use a small leveler and check to make sure your docks are perpendicular to the frame front to back and left to right use the CNC part as your level reference.
this will help your tool changes.
when i first assembled my XL i didn't realize how the CNC part did not really fit into the C Channel to lock it and my docks were raked a little.
it worked fine at first but then i started to have all kinds of tool change problems. so i went through all my docks and straightened them i also put a flat edge on the front to make sure all 5 were in a decent alignment with each other.
that solved that issue.
the entire design is bad it should be bolted directly to the frame with at least 2 points to stop rotation, 3 is best. all the docks should be tied to each other as well but that is more problematic.
i'm sure in the future prusa will change this design.
“One does not simply use a picture as signature on Prusa forumsâ€
RE: Tool Crash Problem Fixed
Today I faced the same problem - also with extruder 4. Thanks for the solution to it. In addition to just torquing the screws I also ran a calibration as the tool change for extruder 4 still run into an issue. Now the printer is up and running again.