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3D Printing

Prusa MK3 - Down for Repairs
Jason Hogue

I made a few unfortunate discoveries today when I tried to start a print on the Prusa mk3.

The fan housing around the hotend has melted and the Bed Sensor is now at a 45deg angle. Trying to start a print in this state will fail the Bed Levelling Check because the sensor can’t see the bed.

The fan housing (other parts?) will need to be replaced.

I started taking it all apart then stopped since I don’t have any replacement parts. Best to keep it together so nothing gets lost.


I also noticed that the hotend does not have a Silicone Sock on it.

It needs one. A sock would have prevented the housing from melting and will also improve print quality as it helps separate the “heating” from the “cooling”.

And yet another unexpected discovery was that the power cable needs to be replaced IMMEDIATELY.

It’s an actual FIRE HAZARD !!

When I was moving the printer from the enclosure to the desk to investigate the bed sensor issue, I grabbed the power cable to unplug it. It was VERY Warm and VERY Soft. This cable is clearly not rated for the current that the printer is pulling. The printer wasn’t even on for 10 minutes!! It’s connection to the printer was even super loose too!! It’s just a really crappy cable and should be thrown away so it doesn’t cause a fire.

I plugged a different cable into the printer. The problematic cable (light grey) is still on the desk beside the printer.

It's worth checking all the other power cables being used by printers to ensure they are capable of carrying the required current loads.

I’m looking at printing replacement parts but exactly which parts should be printed (looks like upgraded parts) and which printer can be used to print them?

Prusa’s STL’s are here:

Any thoughts?

Jason Hogue

Jason Hogue

I have ordered 3 E3D hotend silicon socks from Spool3D (Calgary).


John Ball

We've had a lot of really crappy IEC cables floating around for years now. Stuff rated for AC adapters and computer monitors but is 18 or even 22AWG and can't handle several hundred watts. I've been disposing of them as I can find better replacements but they are still out there as we get a lot of them with the donations.

I know the Makerspace printer used to have a sock on the hot end but both I think were discarded by accident when failed prints fouled up everything with plastic.

Lucas Rietze

Hey Jason,

It's been about 2 months since you last posted, but if you need parts printed I have a prusa mk3+ at home I can use to print the parts for you. Just let me know and I can begin sourcing some material to print the parts.

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