Prometheus E3D improved heat break?
Has anyone tried one of these with the MK2MM?
https://www.distechautomation.com/collections/products/products/prometheus-heat-break-e3d-v6-upgrade
The hot end that came with the MM upgrade has never worked right; the filament jams firmly in the heat break every time. It has also deformed both PTFE tubes. Now the filament has broken off inside the heat sink so it can't be reached. I figure I'll destroy the heat break threads if I try to loosen it with a wrench. The heat breaks and PTFE are not available in the Prusa Store. Since the MMU product is new, I expect replacement parts are months in the future. I have a few of the Prometheus heat breaks. If they work with the MMU, maybe I won't have to wait months more. Thanks.
Re: Prometheus E3D improved heat break?
I ordered 5 replacement PTFE liners with the correct chamfer and taper for the MMU from the store. Are they not in stock? Also, my experience with the MMU has been if the tension on the filament is too loose, it will jam in the hotend, and if too tight, jam in the extruder body.
Re: Prometheus E3D improved heat break?
Not in stock, but thanks for the tips. How do you set the tension? The idler screws?
Re: Prometheus E3D improved heat break?
PR went down the same path of developing a heat break which worked better than the standard; seems that Prometheus have done the same but with a slightly different result.
As it happens, my original heat breaks worked just as well as the "upgraded" MMU heat break. I think it really does depend on the day the heat breaks were manufactured...
Removing the heat break from the heat sink can be problematic. If I receive an assembled hot end, I usually disassemble it before use and remove a lot of the thermal glue from the end of the heat break/inside the heat sink and replace it with a non-hardening paste. My heat breaks will now disassemble without any damage.
I am pretty certain that PR do not use the thermal paste supplied by E3D, but instead use their own thermal compound which appears to be a glue which hardens and makes removal without damage impossible.
That's an interesting comment by @jslick007; I have found it impossible to have the tension set too loose and still have the filament feed properly. Basically, you need to have the tension set as loose as possible to prevent damage to the filament (which can cause feeding issues).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Prometheus E3D improved heat break?
Is it possible to get hold of some of the compound Prusa uses? Your description tells me my current heatsink/heartbreak is toast. The previous time things jammed, I had to take the hot end completely apart, including removing the heatbreak. Once I got the filament out, I unwisely used some more thermal compound on the threads. Now the two pieces are locked together. I have several of the Prometheus heatbreaks and a spare heatsink; I don't want to fuse those as well, Thanks.
Re: Prometheus E3D improved heat break?
Looks like Timtronics 611HTC would fill the bill, but I can't find a place to buy some. For that matter, is thermal compound really required?
Re: Prometheus E3D improved heat break?
I think the thermal paste used by E3D is fine; you just don't need very much of it.
There's a picture here: https://shop.prusa3d.com/forum/-f0/removing-sheared-off-nozzle--t5697.html#p40455 which shows the tool I use for removing the heat break.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…