e3d v6 jamming with taulman bridge

[jeffhuber]

Here the situation:

Hardware
- rostock max v2
- e3d v6 hot end with a e3d 0.8mm nozzle
- Taulman Bridge Nylon

Settings
- 245c print temp
- 0.5mm layer height
- 30 mm/s print speed
- retraction enabled (100mm/s and 5.4mm)

Pictures - here you can see the solidified plastic in the heatbreak and nozzle. this is *after* trying to drill them out
[img]http://i.imgur.com/3Br8JJk.jpg?2[/img]
[img]http://i.imgur.com/51BWNrem.jpg?1[/img]

Every time I print it will work for a while and then eventually the heatbreak will get totally jammed up and I will find the printer moving about not extruding any more plastic. I've drilled out the solidified plastic twice now, and would like to avoid doing it again... thoughts on how to avoid this??

[Lightpath]

I just ordered my e3d v6, so I don't have first hand experience, but I'll chime in anyway. My reading on these forums about the e3d has pointed to retraction issues with PLA, where longer retractions would result in jams. I wonder if you're not seeing a similar sort of issue? Maybe try a retraction distance of 2.5mm or so, just to see how things go. I haven't fooled with retraction because I have thus far haven't had any jams with the stock HE, so I don't know what the impact would be of a much shorter retraction distance.

Very curious about your results, have a spool of bridge on my shelf that I haven't tried yet, so I'm eater to know how you make out.

[jeffhuber]

Hey Lightpath, I will definitely be trying different retraction. Here is a theory - b/c I am retracting 5.4mm - I am pulling molten nylon up into the heat bridge, which then partially solidifies before getting pushed back out again. I noticed the filament in my bowden tube had these little tick marks on them, semi-regularly spaced. I'm guessing this is due to retraction too?

[img]http://i.imgur.com/J29QzVQl.jpg?1[/img]
[img]http://i.imgur.com/ATTOf0ol.jpg?1[/img]

I found this thread on the e3d support forums. It mentions cooling and retraction length being an issue. I'll double check to make sure the fan is always running and also try shortening the retraction length.

[jeffhuber]

Additional *facepalm*. Reading the e3d troubleshooting thread would have likely been helpful, "Retractions of 5mm or more are troublesome as they pull hot filament up into the cold areas of the hotend where they can freeze, adhere and jam."

[geneb]

Welcome to the wonderful world of Facepalmistry.

g.