Keep jamming extruder and messing up prints. Retraction?

[Jimustanguitar]

I'm having multiple problems this evening. Time for some more Bell's Oberon

I've been messing up prints in a very strange way:

First this:

[img]http://i.imgur.com/GqOvzkg.png[/img]

Then this:

[img]http://i.imgur.com/wQILGnx.png[/img]

I also keep jamming my extruder, and I think it's all related. I think the first picture is from skipped steps and my second one is from a jammed extruder.

If my retracts are skipping steps, then the "un-retract" pushes too much plastic out because it didn't draw it back in the first place.... Hence the blobs in the second picture, right?

What speed and current do you use for retraction? I've got one slicer profile that says 60mm/s and one that says 30mm/s. I think it's the 60's that are too fast. Also, what motor current are you using? I've got this in the firmware (right click and "view picture" to zoom):

[img]http://i.imgur.com/oFlXTES.png[/img]

I assume that the pattern in the firmware is (X,Y,Z,E1,E2), right? what current should I bump it up to on the extruder?



Thanks in advance!

[lordbinky]

I checked and my EZ struder extruder motor is set to 235, it has a small fan blowing on the back of it so it doesn't get hot. Damnit Gene I know that's more than I need but I don't ever question it at that setting.

Note: While I haven't noticed any missed step issues, the filament either goes or it gets a chunk taken out of it.

The speeds in kisslicer are 55mm/s - 75mm/s for ABS and 75mm/s for Nylon. I'll knock it down if a particular filament is giving me trouble.

[Jimustanguitar]

Forgot to mention... I'm using the original Steve's Extruder, so for a high speed retract, with all of the gear reduction, it's a really high speed retract.

I'm going to bump it down to 40 or so and see what happens. After I took the screenshot, I bumped my current up to 200. Assuming that it goes x,y,z,e and I even changed the right one.


I've got an EZStruder sitting around. I've been holding off because I want to rig up Glenn's air-struder, but maybe I'll put it on instead of my original to see how it goes.

[dsnettleton]

Take it from me. If Steve's extruder is skipping, the EZstruder definitely will. It looks like you're printing PLA in the picture. Your hotend is probably jammed further up, and all you're getting out of it is ooze. When PLA gets goopy, it likes to do that. Sometimes a shorter retraction distance (with lower temperature) helps, but to be honest, I've been having problems with PLA recently myself.

[Jimustanguitar]

ABS actually. Never mounted up a fan to try PLA.

I changed my retract speeds in Slic3r, so I'll give that a shot next time I fire up the machine.

[Jimustanguitar]

I figured out a little bit of it... Slic3r built into Repetier keeps losing my settings. For example, I discovered that it won't let me enter 30 as the retract speed but 31 works. It also won't let me enter 200 as a hot-end temp but 201 works.

That's weird. Has anybody seen this before?

I'm still getting intermittent speed issues, maybe it's time for some ferrite cores (not that it would have anything to do with Slic3r failing to save my settings).

[geneb]

There's a known bug with the windowing library that Slic3r uses. What happens is that when you manually type a number into one of the fields that has the up/down arrows next to it, it doesn't "take". If you use the up/down arrow however, it _always_ works.

g.

[Eaglezsoar]

There's a known bug with the windowing library that Slic3r uses. What happens is that when you manually type a number into one of the fields that has the up/down arrows next to it, it doesn't "take". If you use the up/down arrow however, it _always_ works.

g.

In all seriousness how in the world did you know that?
Impressed me.

[geneb]

Because I bitched at the author about it and offered to fix it. He explained what was going on. I decided I didn't want the hassle of digging into the window library code.

g.

[Eaglezsoar]

Because I bitched at the author about it and offered to fix it. He explained what was going on. I decided I didn't want the hassle of digging into the window library code.

g.

You helped a lot of people who read your answer. I was having the same problem, thanks for letting us all know the solution.
It amazes me what can be learned on this forum and the knowledge level of many of it's users such as you and many others.