PushPlastic PLA on Taz 6

Help with printing with specific plastic filaments.
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Dershum
Posts: 11
Joined: Fri Aug 28, 2015 12:16 pm

PushPlastic PLA on Taz 6

Post by Dershum » Tue May 29, 2018 7:21 am

Has anyone has much success printing with PushPlastic's PLA on a Taz 6? I've had nothing but trouble with it. I used the Verbatim PLA .25mm profile as a starting point (and the sample Verbatim PLA printed wonderfully) but nothing I've done has been very successful. I always end up with the filament becoming chewed up by the hobbed bolt, and the extrusion stopping. So far I have:
  1. Adjusted the temps - tried everywhere between 190c and 210c
  2. Adjusted and re-adjusted the idler tension - started with 8mm between spacers, and adjusted to tighten. Stopped tightening around 5mm because it was just getting too tight.
  3. Cold pulls - more than I can count.
  4. Adjusted retraction distance/speed, and also disabled retraction.
  5. Mounted a higher-flow fan to cool the hot end (two different ones actually, so I'm up to 3 different fans) - and tried the the temp range of 190c-210c (at 5 degree steps) for each fan.
  6. Tried Printing without guide tube
  7. Adjusted the z-offset
  8. Cleaned the hobbed bolt teeth more times than I can count
  9. Adjusted the print speed - tried 60mm/s, 60mm/s, and 40mm/s
  10. Tried multiple spools of filament
Also, I've printed several successful parts (the same ones that failed) using the ngen sample that came with the printer, and the Verbatim PLA that came with it. And this was between failed PushPlastic PLA prints, so I'm 99% sure it's not a nozzle blockage.

I hate to give up - because frankly, I've had lots of GOOD luck in the past with PushPlastic's products - I used their PLA almost exclusively on my Printrbot with zero problems. Also, I have 5 brand new spools of it that I'd really like to use, vs. trying to return 3 of them that are still unopened.

Any feedback would be greatly appreciated!

Brent.I
Aleph Objects | LulzBot
Posts: 406
Joined: Mon Jan 20, 2014 8:21 am

Re: PushPlastic PLA on Taz 6

Post by Brent.I » Tue May 29, 2018 7:39 am

Fine tuning settings for a new filament can take a little trial and error. We may have a suggestion or two that may help narrow down the spot:
Dershum wrote:
Tue May 29, 2018 7:21 am
everywhere between 190c and 210c
Looking over their website, Push recommends 190c - 220c on their PLA. (https://www.pushplastic.com/collections/pla-filament) Upping this temperature may help as the PLA should be more viscous and flow easier at higher temps.
Dershum wrote:
Tue May 29, 2018 7:21 am
Stopped tightening around 5mm
This is good! The extruder springs should be compressed to 5mm. That is the distance from inside washer to inside washer.
Dershum wrote:
Tue May 29, 2018 7:21 am
Adjusted the z-offset
If you are too close, it can cause extra pressure and strip outs. If you are not seeing "waves" that are perpendicular to your in your first layer travel paths, you should be fine on that aspect.

From everything you describe, I think the temperature being too low is going to be your best bet. Looking over the MSDS sheet linked on Push Plastics site, it looks like decomp temp doesn't hit until 250c so you may even want to try something a little hotter than 220c.

We hope this helps!

Dershum
Posts: 11
Joined: Fri Aug 28, 2015 12:16 pm

Re: PushPlastic PLA on Taz 6

Post by Dershum » Wed May 30, 2018 7:07 am

So I cranked up the temp to 220c last night, and finally got a successful print of my test part - which came out very nicely. I frankly never expected to have to go that hot, since the hottest I ever went with PLA on my Printrbot was around 205-210, otherwise it would turn int a goopy mess.

Also I should have been a little more clear on the z-offset adjustment...I tried several heights, from won't-extrude-too-close-to-build-plate, to almost a full mm above the build plate. In either case, I'm pretty happy with the z-offset at this point.

Going to try a few more parts to see how things go - but at least it's headed in the right direction. Thanks again!

Dershum
Posts: 11
Joined: Fri Aug 28, 2015 12:16 pm

Re: PushPlastic PLA on Taz 6

Post by Dershum » Fri Jun 01, 2018 9:15 am

So far so good running with the higher temperatures, but I am getting some weird fuzzies on some of my prints. Usually I would suspect the heat being too high, or not enough retraction with these, but I wanted to ask if the professionals had any suggestions?

Image

Brent.I
Aleph Objects | LulzBot
Posts: 406
Joined: Mon Jan 20, 2014 8:21 am

Re: PushPlastic PLA on Taz 6

Post by Brent.I » Fri Jun 01, 2018 3:41 pm

You're right that the temp may be a little bit high, as it looks like that is a nozzle drip during those travel moves from one fin to another. I think I can also see a couple strings in the center column as well. When you upped the temperature from 210c, did you go straight to 220 or did you try 215? (Gut reaction)

Retraction speed and distance will be the next place to check. You can try to up the retraction speed, but keep it at 25mm/s or lower. Higher speeds can put extra wear and tear on the herringbone gears. For the distance, just about 1.5mm is a good starting point on distance. Changing that by +/- 0.25mm at a time will be a good way to tune that in.

tl;dr try 215c first, if you are still getting strip outs start to play with retraction at 220

Dershum
Posts: 11
Joined: Fri Aug 28, 2015 12:16 pm

Re: PushPlastic PLA on Taz 6

Post by Dershum » Thu Jun 07, 2018 11:06 am

Fair question - and you're right. I jumped straight to 220c. I figured I wanted to know if that was actually the problem, and was in somewhat of a hurry.

I backed the temps down to 215c and I also increased the retraction distance from .5mm to 1.0mm (I had reduced it while trying to fix the previous problem) and I'm not seeing quite as many threads, but definitely still seeing some.

Going to bump up the retraction to 1.5 to see if that reduces the threads any more, but so far so good. Thanks again for the help!

Brent.I
Aleph Objects | LulzBot
Posts: 406
Joined: Mon Jan 20, 2014 8:21 am

Re: PushPlastic PLA on Taz 6

Post by Brent.I » Thu Jun 07, 2018 12:11 pm

Dershum wrote:
Thu Jun 07, 2018 11:06 am
Thanks again for the help!
Not a problem, good luck and happy printing!

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