Hotend PTFE tube hits Bondtech gears on a MK3S assembly  

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

Hello,

I think trimming it would make sense under the circumstances. It's simple enough to do. I replace mine once a while ago and had the exact same problem causing underextrusion later on. Just trim it down a bit and see how it goes. PTFE tubes can always be replaced for little money.

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

This same issue is happening with me as well. I believe the mk3s printed part that attaches to the extruder motor is slightly off center. Based on a few responses from my own thread that I made ( https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f62/mk3s-stops-extruding-mid-print-filament-grinding--t28052-s50.html ) I believe something is wrong with the mk3s parts.

The inevitability is that my filament kept ended up being grinded down and not extruding, probably because the debris on the bondtech gear piled up from the PTFE tube top.

My solution was to print a collet clip to hold down the PTFE tube since it seemed to be moving mid print, but it did still rub on the gear. I'm gonna go with the suggestion from the guy who posted before me and trim down the top of the PTFE tube as well.

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

Okay. Am just going to cut it down a bit. I was mostly just concerned that I had done something wrong but if other people are seeing this it is likely just an issue and I can proceed with just trimming it a touch and moving on with the assembly. Thanks.

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

Already new the tubes are 45.5mm instead of the mentioned 45.0mm.
For me, cutting the tube to 44.0mm did the trick.

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

The inevitability is that my filament kept ended up being grinded down and not extruding, probably because the debris on the bondtech gear piled up from the PTFE tube top.My solution was to print a collet clip to hold down the PTFE tube since it seemed to be moving mid print, but it did still rub on the gear. I'm gonna go with the suggestion from the guy who posted before me and trim down the top of the PTFE tube as well.

i already have problem with PTFE tube on my MK3 hoping MK3S solve this : filament want to slide up the PTFE when unloading , jaming PTFE into extruder gears...
The black collet https://www.filimprimante3d.fr/buse-extrudeur-175-mm-imprimante-3d/1911-collet-de-remplacement-pour-hot-end-metal-e3d.html here wich supposed to prevent the PTFE tube to go up still provide up/down moves resulting with filament
expend & block down where it reach heated nozzle assembly ... i'm thinking about a mod to lock the PTFE tube down
& also make the heat sink removing easyer ?

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

for unknown reasons Prusa leaves these collet locks/clips off the V6 hot ends they provide follow the e3d instructions when you reassemble your hot end and use a clip... the STL for them is on Thingverse
https://e3d-online.com/collet-clips-pack-of-2

Re: Hotend PTFE tube hits Bondtech gears on a MK3S assembly

Darn, randolph.l, these are pretty nice. My PTFE tube never moves as far as I can tell (hence I am not sure why other would have that problem or why there is so much variation), but I'll pull the STL file and print myself one of those. Thank you.