Dino Jam!

[lewis1914]

I'm attempting to print the makerbot pocket t-rex skull ( http://www.thingiverse.com/thing:373367 ) and am having issues.

I can print larger items without any issues. These particular prints keep failing in the same spot. I've tried printing one at a time and two at a time and the failures are the same.

The ezstruder jams horrifically each time. I have to take the full ezstruder apart to clear the jam. I tried two different ezstruders (one has a stronger spring than the other. Both fail the same way)

The printer is a Rostock max V2 and an E3D V6 hotend. The nozzle is a .4mm. The filament is Matter Hackers white pla. I'm printing at 215 degrees. My print speeds are between 30 and 50mm/sec. Layer height is .2mm

I think the issue is at the hot end side of the equation. I read someplace that E3D hotends like to jam if the retracts are bad. My retract speed is 20mm/sec. I have tried a retraction length of both 3mm and .5 mm. Both fail the same way.

What could be causing this, and more importantly how can I fix it?

[DavidF]

would you mind trying one of the 15.00 hot ends from folgertech?? I have been having good luck with it and pla...

[jmpreuss]

How hot is your extruder motor getting? It looks like your PLA is getting soft in an area where it shouldn't be and if your extruder motor is really hot that could be the cause. It may not be a hot end issue.

[Eaglezsoar]

I agree with jmpreuss, the filament is being melted at the extruder.
From the looks of the filament at the extruder the extruder motor is so hot you will not be able to touch it for very long.
What happens when you try one of the small prints when the printer is first turned on and is cold?
Check the current settings for the extruder in your configuration file.

[DavidF]

Meh ive had a few times my pla balled up like that around the stepper and mine runs pretty cool.
I had the good luck with the e3dv6, up unti this one part i made several attempts at printing and it jammed about the same point every stinking time!! And it was on a 50 hour print and would do it half way through. The problem was the filament binding in the heat break due to heat creep up the filament.
The folgertech hot end has a ptfe tube running through the heat break. So far it has not jamed up on me.

[Captain Starfish]

The only time I've had that issue is with PLA in an E3D V6.

Retraction was the culprit. Have a poke around, there's plenty of writeup - but the short version is get your retraction short (2mm max) and slow (15mm/s) and you should be much better off.

[lewis1914]

My stepper is a kysan 1124090 7951.

The extruder stepper is fairly hot, but the hobbed bolt isn't very warm.

My motor current settings are:
MOTOR_CURRENT {155,155,155,165,0}

I am considering changing them to:
MOTOR_CURRENT {140,140,140,130,0}


The user guide suggests the 155 settings, and the comment in the configuration.h code suggests the 140 settings.

Which is this the correct set of settings?

[DavidF]

you can try backing the current down some to 140. Its not going to hurt

did you order the hot end yet?? LOL

[Nylocke]

If you want a real quality hotend for PLA the J-head (from hotends.com) is regarded as the best by most. You could also try a flying extruder with a better extruder design than the stock EZstruder, it shortens the tube length and reduces the friction the filament encounters in the bowden tube (actually a fair bit when the tube bends and curls around). It also minimizes the amount that the filament can bend in the tube/the tube can flex. It should increase extrusion force (since less force is used to overcome friction) and decrease hysteresis.

[DavidF]

If you want a real quality hotend for PLA the J-head (from hotends.com) is regarded as the best by most. You could also try a flying extruder with a better extruder design than the stock EZstruder, it shortens the tube length and reduces the friction the filament encounters in the bowden tube (actually a fair bit when the tube bends and curls around). It also minimizes the amount that the filament can bend in the tube/the tube can flex. It should increase extrusion force (since less force is used to overcome friction) and decrease hysteresis.

I have tried the J head, I didnt think the print quality was as good as the e3dv6 but it did print pla well without jamming. The folgertech prints the same quality wise as the e3d. Thats why im liking it.
hoping to get a couple others to try it out. 99% of the time im printing in pla so having the right hot end is very important.

[geneb]

Have you tried a j-head or the j-head? There's typically a huge difference. The clones are shit and should be avoided. (If it didn't come from hot-ends.com, it's a clone)

g.

[DavidF]

Have you tried a j-head or the j-head? There's typically a huge difference. The clones are shit and should be avoided. (If it didn't come from hot-ends.com, it's a clone)

g.

Yes a j head, from hot ends.com.

[Eaglezsoar]

Many, Many users are using the E3D V6 hotend to print PLA without any problems.
Switching to a jhead to fix the problem is a band-aid approach, this user's E3D V6 should
work to print PLA as well as the other many users. Is the nozzle drilled out to MHackney's
specifications is one thing that needs checked as well as all the other guides and how-to's
MHackney has printed. There is a great search function on this forum that I bet not more
than 20% know how to use. Here it is again.....
Open browser and type in your browser's seachbar - site:forum.seemecnc.com ???????
The question marks indicate what search word you are looking for. For example, if you want
to search on the word E3D then you would enter site:forum.seemecnc.com E3D
into your browser's seach bar and press enter.
I said it once and I will say it again, the E3D V6 will print PLA! Here is a good topic http://forum.seemecnc.com/viewtopic.php?f=54&t=1682

How did I find that topic? site:forum.seemecnc.com E3D PLA in the search bar! This is a great forum and is full of great information but learn
how to find that information...

A note from Sanjay (one of the owners of e3D)
Jarrett - If you're having problems we'll sort you out! No drill bits needed. Just get in touch on our contact us page http://e3d-online.com/ContactUs on our site. If you need a new nozzle you need a new nozzle. We don't expect our customers to have to take drill bits to our product to get it to work. He is saying that if you have a problem with the E3D contact them, they will help you to get it working, including printing PLA.

[DavidF]

I have plenty of hours on the v5 and v6 with pla and I am not knocking its quality. But truth be told there can be a pretty fine window with the temp and print speed when you start running into alot of retractions.
From what i have experienced, its not the nozzle plugging, but the pla softening in the heat break area then when it retracts and resumes printing the pla mushes out in the heat break area and binds up and the heat break is too cool to soften the pla before it strips at the extruder. So i got the idea to run a ptfe tube through the heat break area (sort of like a j head) and ran across the folgertech website where i saw they had heatbreaks with the teflon run inside them like i wanted. So i ordered 2 of those heat breaks with the intention of putting one into the e3dv6 but then i saw they offered an all metal hot end for 15 bucks and said what the hell ill modify it instead of screwing up my v6. Thinking it was a clone of the e3d i expected the heat break to be all stainless so when it arrived 8 disassembled it to change the heat break and what do you know? It was teflon lined.
Ive printed alot of things in pla with the e3d hot ends with no problems, but this one model was killing me so i started looking at the problem i was having and a quick fix.
Im not trying to support any one product and i dont sell products to the 3d printing world.

[DavidF]

Lewis1914, drop your extruder temp to 185c, speed 20mm/sec, retracts to 1mm at 20mm/sec.
I think that should fix you up, provided that white pla isnt that "cat hair" filament i had awhile back.

[lewis1914]

I successfully printed the dino head!

I changed the motor current values to the suggested versions in the source code. The stepper does run a little cooler now. I think that this was the actual issue.

I reduced my retract speed from 20mm/sec to 15mm/sec.

My retraction length is 2mm (I doubt this was the issue as I had faults at both .5 and 3).

All my other values (print speed, nozzle temp, etc) stayed the same.

My original failures were with a .4mm nozzle. I printed the one in white with a .6mm and the one in blue with a .35mm nozzle. The difference in quality isn't really all that noticeable.