possible heatbreak issues causing jams  

Re: possible heatbreak issues causing jams

Looks like the ptfe tube was not pushed all the way down into the heatbreak. See the E3D website for more info about this. If necessary, replace the ptfe with a longer piece.

Re: possible heatbreak issues causing jams

I agree with Geof..

I'd try to clean this out carefully, maybe more acetone or a blow torch.. Drilling sounds a bit rough.

Or get a new heatbreak and a bit of ptfe tubing from e3d-online.com (UK based)

http://e3d-online.com/E3D-v6/Spares/v6-Heat-Break-1.75mm

http://e3d-online.com/E3D-v6/Spares/Bowden-Tubing-1.75mm

When reassembling make sure the tube is cut at exactly 90°, then push the tube all the way in and lock it in place by pulling out the black plastic ring on top of the heat sink.

PS: I unfortunately do not know how long the ptfe tube needs to be for the MK2(S) . Maybe measure yours before ordering. Oh, and if you happen to measure it, let me know please 😉

Re: possible heatbreak issues causing jams

Those images where taken from the hot side. The ring looks like metal from incomplete drilling.

The cold side with the PTFE tube looks good to me.

Re: possible heatbreak issues causing jams

When reassembling make sure the tube is cut at exactly 90°, then push the tube all the way in and lock it in place by pulling out the black plastic ring on top of the heat sink.

OK, there are a couple of issues here.

1. I always start with a PTFE tube that is slightly longer than necessary and cut it to length at the top when assembled.

2. The heat break is actually chamfered; it is much better to add a matching chamfer to the PTFE tube (a pencil sharpener used carefully works for this), and ensure you remove the internal burrs from the PTFE tube (reamer on Swiss army knife - be gentle).

3. Unscrew the heat break a quarter of a turn from the heat sink, insert the tube and lock in place and then tighten the heat break into the heat sink.

Peter

Re: possible heatbreak issues causing jams

1. I always start with a PTFE tube that is slightly longer than necessary and cut it to length at the top when assembled.
2. The heat break is actually chamfered; it is much better to add a matching chamfer to the PTFE tube (a pencil sharpener used carefully works for this), and ensure you remove the internal burrs from the PTFE tube (reamer on Swiss army knife - be gentle).
3. Unscrew the heat break a quarter of a turn from the heat sink, insert the tube and lock in place and then tighten the heat break into the heat sink.

Hey, even better than E3Ds own instructions. They chamfer the inside of the feeder end, but doing the outside at the heatbreak end sounds like a good idea. I'll try that next time i have to redo mine. Thanks!

Peter, any idea on that odd burr Karsten has?

Those images where taken from the hot side. The ring looks like metal from incomplete drilling.

I indeed thought it was leftover filament on the cold site.. If that's metal, i guess drilling this out is your only option.

I checked my 2 spares and while ones as smooth as a baby butt, the other one has some rough spot, but nowhere near as bad as that burr of yours. Well, here's pictures.. left one is part of the spare hotend kit i ordered from e3d, right one is a spare i ordered someplace else.

Edit: actually attaching the picture might help.. doh.. not my day today.

Re: possible heatbreak issues causing jams

Peter, any idea on that odd burr Karsten has?

Well it does look very much like residue filament from a blockage. I doubt if it is a metal burr.

The inside of the heat break should be as smooth as possible. Use a 1.8mm drill, put it inside the heat break (held in a rubber-jaw vice) and turn on the drill at high speed. move the drill around using the flute sides as a reamer to polish the inside. Maybe even use a bit of toothpaste as a mild abrasive, but wash out thoroughly afterwards.

(And yes, I have done this as well, not on the heat break, but the cooling tubes of the MM upgrade).

Peter

Re: possible heatbreak issues causing jams

Just did a quick round with the drill bit without any actual drilling and could remove some black particles. Still got something in there but it is getting a bit late for real drilling here

Re: possible heatbreak issues causing jams

Please accept a noob question (and I hope I am not hijacking this thread).
I thought the I3MK2 hotends were supposed to be "all metal" hot ends. So they still have some PTFE tubing inside? It may be a misunderstanding from my part but I thought the point of having an all metal hot end was to get rid of the PTFE.
If PTFE something I should buy and keep in stock for the I3MK2?

Thanks,

Fosk

Re: possible heatbreak issues causing jams

Please accept a noob question (and I hope I am not hijacking this thread).
I thought the I3MK2 hotends were supposed to be "all metal" hot ends. So they still have some PTFE tubing inside? It may be a misunderstanding from my part but I thought the point of having an all metal hot end was to get rid of the PTFE.
If PTFE something I should buy and keep in stock for the I3MK2?

Thanks,

Fosk

On the V6 the PTFE is only in the cold end. The Lite6 has the PTFE running right through to the hot end, limiting the temps that can be used.

The V6 max temp is around 300 degrees, limited by the thermistor, whereas the Lite6 is around 240 degrees limited by PTFE.

And yes, it's always worthwhile having a variety of spares, including PTFE.

Peter

Re: possible heatbreak issues causing jams

Just did a quick round with the drill bit without any actual drilling and could remove some black particles. Still got something in there but it is getting a bit late for real drilling here

OK, so I have been finding out about the manufacture of the heat breaks.

The issue is that they need to be machined from both ends and the undercut between the two threads (to about 2.95mm) has to be cut before the hole is drilled. Therefore the hole has to be drilled from both ends and many heat breaks being shipped have slightly offset holes, leading to an internal ridge 5 to 7mm from the hot end.

It should still work fine with the standard Mk2, but may have issues with the MM upgrade. It's still worth cleaning out as much as you can, but don't enlarge the hole and ensure it is thoroughly washed out afterwards - you don't want metal filings blocking the nozzle.

Peter

Re: possible heatbreak issues causing jams

On the V6 the PTFE is only in the cold end. The Lite6 has the PTFE running right through to the hot end, limiting the temps that can be used.

The V6 max temp is around 300 degrees, limited by the thermistor, whereas the Lite6 is around 240 degrees limited by PTFE.

And yes, it's always worthwhile having a variety of spares, including PTFE.

Peter

Thank you for the explanation I was mislead by the term "all metal hotend" and I assumed it meant there was no PTFE at all.