MakerGear Forum

I've made a couple of attempts at printing http://www.thingiverse.com/thing:28202 but with no success so far - the right (metal only) extruder keeps clogging. Of course I'm not sure WHY this is happening, I'm printing with PLA in both extruders and swapped the colors to make sure it wasn't the plastic. With the V3B hotend I was using the 225C temp from the rsilvers profiles, but tried 215C since the wiki page recommended it. Then I upped it to 220C and also got a clog.

I see a bunch of possibilities here. I'm noticing that it's the all metal hot end that's clogging and that the right extruder is spending more time idle.

Has anyone seen anything like this?

<edit> forgot to mention that I'm printing it at half size - I cared more for the process than the end result.

I had the same issue with pla and the fist few layers. I think that the tip was moving over some drool and getting plugged from the blobs on the glass. I haven't seen this with ABS on the right side.

If it's the toolpaths, then it may be wiping the same drool in the same spot on the same side every time. You might see a difference if you rotate the model, or try a model like the tree frog with more change in the toolpaths from layer to layer.

I think, though, that we all just have to get used to using Cura and generating wipe towers and ooze shields. I got a late start on the dual extruder assembly and am not quite at that point, though. There's a lot of experimentation to be done by everybody. . .

I'm trying again with ABS tonight - so far no clogs and noticeably less drooling. I'd really rather not rule out PLA for dual color prints though.

Hi everyone,

I'm experiencing the same issue. It seems to be a known all-metal extruder problem with PLA
(see e.g., http://forums.robo3dprinter.com/index.p ... -jam.2328/)


Two solutions are proposed here:
http://blog.reprap-india.com/2014/04/03 ... al-hotend/

I'm currently trying the 'seasoning' solution. The idea is to apply cooking oil to the hot end such that the filament does not stick to metal as well as it naturally would.

... so this time, with the 'seasoned' extruder, I didn't encounter a clog with PLA on both sides
for this print (http://www.thingiverse.com/thing:11660 half size):

Did you method of "seasoning" differ from that mentioned in the blog?

One thing the article didn't mention was whether they were "seasoning" a brand new, unused extruder, or a used one. If it has clogged, then presumably plastic has been sticking to the metal already. I would have thought that you would want to crank the temperature way up to burn off the PLA first. In fact, I would think that if you want to oil the inside of the nozzle, it would be better to do it with a higher-temperature plastic like PET. But there's no real theory behind that argument, and definitely no materials science knowledge.

Tim wrote:Did you method of "seasoning" differ from that mentioned in the blog?

One thing the article didn't mention was whether they were "seasoning" a brand new, unused extruder, or a used one. If it has clogged, then presumably plastic has been sticking to the metal already. I would have thought that you would want to crank the temperature way up to burn off the PLA first. In fact, I would think that if you want to oil the inside of the nozzle, it would be better to do it with a higher-temperature plastic like PET. But there's no real theory behind that argument, and definitely no materials science knowledge.

It differed in the sense that I didn't pull the PLA out again. I just dipped the filament I was going to use in oil and extruded for a while (such that more than the oily part of the filament was extruded). Then I just started printing.

Every 10 or so prints I have to pull my hot end and take a propane torch to it and let all of the plastic drip out.. The 35 mm tip will last longer, but I can never get more than 10 or so prints out of my 25mm nozzle without the propane trick.

Maybe after my next propane torch cleaning, I'll try this trick to see if I can get more prints before needing to clean it again.

What kind of oil did you use? I suppose Avocado is the good high temp choice these days.

Woah don't do that. You'll bake contaminants in.

Get a roll of Taulman 618 and do a few cold-pulls with it. It cleans nozzles really, really well.