problems with force required for PLA

I am using a direct drive extruder (http://www.thingiverse.com/thing:501755) and some no-name PLA filament I have seems to require a LOT of pressure to get pushed out of the extruder. when it's running I can hear it start to make a creaking noise (the noise you hear when you apply force to plastic). at first I couldn't figure out the noise but now I see that it's because the gear is pushing the plastic down with such force that the filament is actually starting to bow outwards, and eventually during my print it gets to be so much that the filament jumps out of the gear.

now, I don't think it's anything to do with my extruder setup because i also have two spools of Hatchbox PLA and that stuff prints AMAZING! I am to the point where I am just going to dump the no-name stuff. but I have this huge roll and hate to get rid of it. I am wondering if maybe they sent me abs instead of PLA? I have ran the stuff upwards to 230C and it still doesn't seem to help, although it's better. And I had thought that maybe it was because my print speed was too high but running at 40mm/s still didn't help.

Any ideas? should I crank the temp up to ABS temps and see what happens? That seems like I'm asking for trouble but I don't know.

I would try raising the temp, even if you pull the filament out and touch the outside of the hotend with it to see @what temp it melts quickly. If it really was PLA and your temp was really at 230c... PLA would be oozing out of the HE in a long string. litterally soo hot/melty its falling out of the HE.

I have had experience with about 6 different brands of plastic now and they all seem to have different properties. Different melting temperatures and different viscosities at those temperatures. If you're judging the plastic by the standard temperatures that get quoted around here then ultimachine is the best stuff in my opinion; however, I have got off brands to print well but not at the normal the temperatures and feed rates. my suggestion is if you don't want to pay ultimachines price then play around with the off brands and figure out how to print with them.

My current i3 build is wearing parts made from all off brand PLA and ABS.

that's the weird thing, it sounds like 230 is the ABS temp and even then it's hard to get the filament out. i can't imagine what is really the problem with the filament. I don't think I remember it oozing at all that's the weird thing. but even at abs temps what could be the problem?

That definitely does seem odd for PLA. If you burn something with a lighter does it smell kind of sweet. burn some of your good abs and compare the smells. PLA kind of has a sweet smell like antifreeze and abs has a chemical smell.

One of the cheap PLA I had required that I turn up the temperature to get it to melt but turn down my esteps because it was too liquidy.

Could this be due to heat creep?
if you don't have cooling on your hotend you can have the transition point for your filament get higher and higher within the hotend resulting in more molten plastic more friction and potentially a jam.

i actually thought it could be heat creep a while ago because I had a similar problem with the noise when using MG Chemicals filament. It wasn't so bad that it was skipping the gear though. So at that point I replaced my original J-head hotend with a E3D v6 because i liked how it had a dedicated cooling fan for the upper part of the hotend.

i'll have to try burning some of it with a lighter to see how it behaves.

Quote
appdev007
I have had experience with about 6 different brands of plastic now and they all seem to have different properties. Different melting temperatures and different viscosities at those temperatures. If you're judging the plastic by the standard temperatures that get quoted around here then ultimachine is the best stuff in my opinion; however, I have got off brands to print well but not at the normal the temperatures and feed rates. my suggestion is if you don't want to pay ultimachines price then play around with the off brands and figure out how to print with them.

My current i3 build is wearing parts made from all off brand PLA and ABS.

What's the highest you've had to go with PLA?

I had to go up to 194 to get this one brand to stick together well. Had to lower my e steps a bit too because it was to thin at that temp and was over extruding.

Sounds like it is not the correct size.MEASURE it with calipers and I bet it is larger than spec.GL