PLA Woes

[osr]

Hey, thanks McSlappy. I've got my Rostock running great now. I had a bad bearing on my EZstruder and a missing outer PTFE tube in the hot end. Now with an E3D and my printed extruder, I can print PLA as fast as I want to. I've been testing the SeemeCNC hot end on another printer I'm building, and it's functioning okay now that I've got it assembled correctly. It doesn't even come close to the performance of the E3D though, so I'll probably get another E3D to replace it. The EZstruder would probably work too if I changed the bearing, but I don't have one and I like mine better anyway. Good luck with your printing, and thanks for the encouraging words.

[Eaglezsoar]

Hey, thanks McSlappy. I've got my Rostock running great now. I had a bad bearing on my EZstruder and a missing outer PTFE tube in the hot end. Now with an E3D and my printed extruder, I can print PLA as fast as I want to. I've been testing the SeemeCNC hot end on another printer I'm building, and it's functioning okay now that I've got it assembled correctly. It doesn't even come close to the performance of the E3D though, so I'll probably get another E3D to replace it. The EZstruder would probably work too if I changed the bearing, but I don't have one and I like mine better anyway. Good luck with your printing, and thanks for the encouraging words.

You really should replace the bad bearing on the EZstruder and see how it compares to your printed extruder. If hundreds of others can use the EZstruder successfully there is no reason
that it won't work for you.

[v8tony]

Is your trouble all on the first layer? If so, try making your Z distance shorter by 0.1 or 0.2mm in the EEPROM settings... I had a problem where it would extrude into open air just fine, but, the added pressure of the narrow gap on the first layer would put enough backpressure to cause skipped steps... If this continues to happen after maybe the 3rd layer (when things should have evened out) then that might not be your problem... Just my 2 cents...

I'm very happy with my upgrade to the EzStruder. The 3 Things I wanted all worked out...

1 - Much easier to change filaments
2 - Quieter (my old one creaked)
3 - Smaller and lighter and I printer a mount to hang it from the top (I'm going to enclose my printer and didn't want the spool/extruder hanging off the side)

I love the support you guys give on this board... Thanks for all your time...

Tony

[Glacian22]

Hey all, I finally solved all of my PLA problems. First off, the ezstruder wasn't gripping *quite* hard enough, so I put a small shim in with the spring to add a little tension, as sometimes the motor would spin and the filament wouldn't move. With that better grip, the motor would often skip. I tried a wide range of temps, as people were saying that this meant I wasn't getting the PLA to flow well enough through the nozzle. At 220 it was still skipping like crazy, which is high for PLA.

Eventually I just bit the bullet and tried running really hot. At 230 I can print without skipping at 90mm/s. Problem solved!

[mhackney]

What do you have the stepper's current set at? If you are using Repetier, you can do this in the firmware. I had a similar skipping issue and simply raising the stepper current to from 175 to 200 did the trick. Look for this in Configuration.h.

// Motor Current setting (Only functional when motor driver current ref pins are connected to a digital trimpot on supported boards)
#define MOTOR_CURRENT {175,175,175,200,200} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

[Eaglezsoar]

Hey all, I finally solved all of my PLA problems. First off, the ezstruder wasn't gripping *quite* hard enough, so I put a small shim in with the spring to add a little tension, as sometimes the motor would spin and the filament wouldn't move. With that better grip, the motor would often skip. I tried a wide range of temps, as people were saying that this meant I wasn't getting the PLA to flow well enough through the nozzle. At 220 it was still skipping like crazy, which is high for PLA.

Eventually I just bit the bullet and tried running really hot. At 230 I can print without skipping at 90mm/s. Problem solved!

230C is pretty hot for PLA but if it works for you without problems then I'm glad that you found something that worked.

[seedjar]

I'm having similar troubles, been at it for like two or three days now. At first my first layer wasn't sticking at all, but after tweaking my Z height and cleaning the bed I seem to have overcome that.

Now I seem to be skipping and grinding filament quite a bit. I was trying to get the settings dialed in based on PartDaddy's owl thread but about halfway through my second (semi-successful) test print the hot end has jammed completely. I even brought it all the way up to 230c, thinking I might not have purged all the ABS when changing spools, and it felt just as solid as when it was cold. Tips?

My guess is that I'll need to disassemble the hot end to fix this. If I do, can I reattach it to the other set of mounting holes on the delta platform? I'm asking because I printed this duct to use the 40mm fan I had on hand - https://www.thingiverse.com/thing:104483 - but the mounting holes are all 60 degrees off and I can't figure out how to fix the model without totally recreating it. For now I'm using this one by grabercars - https://www.thingiverse.com/thing:28412 - but it doesn't seem to work very well. Today I came across this one - http://repables.com/r/127/ - and might try it once I get my hot end working again.

Thanks,
~Joe

[Eaglezsoar]

I'm having similar troubles, been at it for like two or three days now. At first my first layer wasn't sticking at all, but after tweaking my Z height and cleaning the bed I seem to have overcome that.

Now I seem to be skipping and grinding filament quite a bit. I was trying to get the settings dialed in based on PartDaddy's owl thread but about halfway through my second (semi-successful) test print the hot end has jammed completely. I even brought it all the way up to 230c, thinking I might not have purged all the ABS when changing spools, and it felt just as solid as when it was cold. Tips?

My guess is that I'll need to disassemble the hot end to fix this. If I do, can I reattach it to the other set of mounting holes on the delta platform? I'm asking because I printed this duct to use the 40mm fan I had on hand - https://www.thingiverse.com/thing:104483 - but the mounting holes are all 60 degrees off and I can't figure out how to fix the model without totally recreating it. For now I'm using this one by grabercars - https://www.thingiverse.com/thing:28412 - but it doesn't seem to work very well. Today I came across this one - http://repables.com/r/127/ - and might try it once I get my hot end working again.

Thanks,
~Joe

Thanks for pointing out http://repables.com/r/127/, I am going to try that one also. Good luck with your cleaning.

[osr]

I have found that everything has to be just perfect to keep a direct drive extruder from skipping. The temp has to be hot enough, the pressure on the extruder bearing has to be just right, and there can't be any friction anywhere.

The temperature readings vary with thermistor type and placement. The same filament that prints at 195C through a Jhead needs 210C on the E3D, and even hotter with the SeemeCNC hot end. I really need to get a thermocouple to see if all the nozzle temps are the same.

If the extruder is too loose, the filament will get shaved. If it's too tight, the deformation of the filament will create friction.

I've gotten a few spools worth of problem free prints out of the Rostock since I got the E3D, but I just put in a new roll of filament and started getting skips again. It turned out that the roll was not wrapped as well as usual, and the extruder can't pull one strand out from under another. It can easily be pulled by hand though. I have to babysit prints again, so I'm not using the Rostock much now.

I think I'll try Richrap's extruder next.
http://www.thingiverse.com/thing:60531