E3Dv6 jamming when printing smaller objects:(

[loiphin]

Hi all,

So I have temporarily given up on my E3Dv6. It seems to jam consistently when it starts printing smaller detailed parts of an object. For example, when it prints the cabin part of 3DBenchy it jams up. And I cant work out why. It did this on two occasions in a similar spot.

I have manually fed in filament through the extruder while hot and its quite easy to push through.
Firmware is updated for E3Dv6 thermistor.
I reduced retractions in my S3D settings to 0.5mm

Could it be that hob bolt is chewing up the filament too much and altering the dimension of the filament, thus causing it to get stuck?

Anyone got any ideas?

Thanks in advance,

loiphin.

[Jules]

I haven't seen it (yet), but innkeeper was saying the other day that it is possible for little bits of plastic to get in there and jam up the teeth so you might want to check that out, it's in this thread:

viewtopic.php?f=3&t=2694#p16367

[jimc]

Be sure the 30mm fan is working. If so then only other thing assuming you assembled the hot end right would be too much tension on the filament. That does not need to be tight at all.

[loiphin]

Thanks for all the tips. Looks like I had cranked up the filament tension way too high! Now its printing fine, with barely any tension on it at all. Just to be sure, I am printing another of jimc's E3Dv6 filament drive as I wonder if my original one is a bit warped.

[jimc]

If that is printed in abs at 80-90% infill i find that i basically need no tension on the screw for most plastics except bridge nylon and ninjaflex. Only really need to put tension on things like nylons and ninjaflex

[loiphin]

So the filament drive was an issue, but I think the root cause is in fact that when printing PLA (at least in my case) there is heat soak, which causes the filament to heat up in the heatbreak and get jammed.

And then today I noticed on the E3Dv6 assembly instructions they have snuck in an additional step to use thermal paste between the heat break and heatsink to improve thermal transfer. And its been added to all kits from now on! So it must be pretty widespread.

http://wiki.e3d-online.com/wiki/E3D-v6_ ... l_Compound

[jimc]

i have used thermal paste and not used it. i really see no difference either way but it does lube the threads so the heatbreak wont bind up in the aluminum block over time. if the 30mm fan is on at all time you should not get much of any heat transfer up past the heat break. that thing should print pla with no issues at all. one thing to be sure is that the ptfe liner is all the way down into the heatbreak. if its not then there will be a tiny gap that molten plastic can work its way into. i put a bevel on the end of my liner to match the bevel on the inside of the heatbreak so it sits in there seamlessly.

[loiphin]

I am pretty sure my E3Dv6 build is good. I have double checked all the things you have mentioned.

ABS works fine by the way. I am assuming the higher melting temperature eliminates any jamming in upper portion of the heatbreak.

According to this post, a number of people seems quite happy with the thermal paste fix...

http://forum.e3d-online.com/index.php?t ... ssues.278/

[loiphin]

Looks like it solved the issue!!!

I did two things:

* Put a piece of Kapton tape around the heater block. Just a temporarily measure until I get some some fibreglass sleeve to help insulate the block against the fan for PLA.
* Applied thermal paste to the threads between the heatbreak and heatsink on the E3Dv6. (This is what actually fixed the problem)

Printed off 3 Marvins at 0.1mm in PLA, one at a time, and not a single jam! Previously, when printing a Marvin it was guaranteed to jam.

http://imgur.com/dSliItN

[Kulturfolger]

Tape tape like this (http://www.supergluecorp.com/?q=super-g ... e-red-25ft) around the heater block. This is a common thing on j-heads, the heat creeps the hotend when there is barely movement, like printing the first layer extremely slow.