Prusa Research & e3d PTFE preparation instruction difference  

Re: Prusa Research & e3d PTFE preparation instruction difference

Maybe prusa found a way of reducing gaps between the ptfe and heatbreak

Regards Joan

Re: Prusa Research & e3d PTFE preparation instruction difference

The E3D drawing shows a chamfer where the teflon tube butts up to it, so it makes sense to taper the OD of the teflon tube on the hot side.
https://e3d-online.dozuki.com/Document/efnkFjIGbsNCBb5v/.pdf

I can't quite see using a pencil sharpener, so I used some sand paper. I'm confident a clever person could come up with a tool to do it perfectly.

On the inlet side, it makes sense to taper the ID so the filament has an easier time feeding in.
I did this part with a hobby knife--it's not critical, just make sure you don't leave any bits on the ID.

Re: Prusa Research & e3d PTFE preparation instruction difference

I understand there is a chamfer in the heatbreak which does make sense to me why you might want to chamfer the PTFE tubing to match but 2 points. Firstly, e3d do not recommend doing so. Doesn't that strike you as odd if it is 'better' to do so? Second, the chamfer angle of the heatbreak is not 45 degrees but shallower. So much so that it looks like a 45 degree chamfer cut of the ptfe tube might cause it to pinch when trying to fit the tube into the hotend snugly. I'm wondering if that might be the cause of clicking that I and some others have been experiencing with the latest firmwares with reduced extruder motor current.

Re: Prusa Research & e3d PTFE preparation instruction difference

Both methods work, as the straight cut practice was the original instructions for the MK2(S). I would suggest that they found an improvement, being that they have more E3D V6s running 24/7 than anyone else. That is a benefit of PRUSA printing from his own farm. I have not seen a difference, nor a problem using either method, but decided to follow Prusa's guidelines as they have the experience. Just a thought.

You might also notice that we do not use the blue collet either. I wondered about that, but in reality, if installed properly, there should be no room to move and it is an extremely fiddly little part which most everyone would lose, and then contact support. I suspect that they try to make it as easy and repeatable as possible for a wide variety of builders.

Re: Prusa Research & e3d PTFE preparation instruction difference

I have replaced my PTFEtube last sunday. But i just cut it straight. I dont make 45 degree cut in it. and what should i say it just prints ans prints and prints and.........

So i think both things wors.

Re: Prusa Research & e3d PTFE preparation instruction difference

Hi Dennis,

we found with the MMUv1, that the chamfered bottom worked better than the square bottom. both work and if all is well, nothing else will interfere this and we are all happy, however with 3D printing often several items can work together to create a problem which no one item would create.

you are free to use your preferred option,
I will use the chamfered version,

neither is more right than the other...
best wishes, Joan

Re: Prusa Research & e3d PTFE preparation instruction difference

Believe it or not... there's a new cutting jig out there that cuts it at a different angle than 45, and that seems to work better (for me at least). Vecko made it 🙂

Re: Prusa Research & e3d PTFE preparation instruction difference

For what it's worth, the hole is probably made by a drill bit with a 135 degree point.

Gary

Re: Prusa Research & e3d PTFE preparation instruction difference

Believe it or not... there's a new cutting jig out there that cuts it at a different angle than 45, and that seems to work better (for me at least). Vecko made it 🙂

Is said jig available somewhere to buy or build?

Nevermind, shoulda gone to Thingiverse first. For those interested: https://www.thingiverse.com/thing:3062809

Re: Prusa Research & e3d PTFE preparation instruction difference

Based on my experience there is no need for high precision PTFE tube cut. It doesn't really matter if you have 45,50,55,62.... degrees cut.
Most important is a uniform cut and slightly chamfered bottom to fit better. On the other side just drill it or use a sharp cutter to make the whole bigger, so the filament can easily slide in.
BTW on MK3/MK2.5 I found 52mm is better size and allows easier TPU printing.

Re: Prusa Research & e3d PTFE preparation instruction difference

E3D updated their drawings on the angle, to make it 45 degrees.... on 8/30/2018.
Just a fast fyi. Vecko updated his STL as well, to stay atop that.