Printing/Config Questions

First off, this is a long post and I apologize if it gets “wordy” or hard to follow. I’m just trying to give you all the details you need in order to help. If I need to explain something better, please let me know.

Hello, I got my Lulzbot Taz 4 on February 12th, 2015 (the same day the 5 came out http://www.facebook.com/LulzBot/posts/851143351611624) and it worked great the first couple of weeks. I even installed the upgraded hot end you sent me without a problem but ever since the upgrade it really hasn’t printed all that well.

Sometimes it wouldn’t print anything at all so I’d have to raise the hot end up and just extrude filament until the clog was fixed. Most of the time it looked like the filament had a bite taken out of it. There would be little flakes of plastic all over the inside of the extruder where the filament goes. I did some research and found out it was the Hobbed bolt that was causing that and it could have been from cheap filament (for the record I got a roll of ABS and PLA from Adafruit so I thought it would be good filament). To try and remedy the filament problem I bought a roll of PLA and ABS from you guys in red so I could for sure tell the difference (the Adafruit filament was white). The new filament kind of solved my problem… for a while. The Hobbed bolt took a chunk out of this filament, too. Also, it prints the first layer okay and then goes all screwy when it tries to build the layers. I was trying to make one of your octopus prints and I found my printer trying to print in mid air.

I have tried a couple of your slicer profiles but nothing works. I even raised the temperature since I have the new hot end that can get hotter. Also, I never really could print from the SD card all that well. I always had to have my laptop plugged into the printer. This isn’t a problem, I was just wondering what would be the reason for the different printing performances.

Here are some pictures of the last prints I tried to do:
https://goo.gl/photos/ndsopkzAgaFiYBxu8

Thanks for taking the time to read this. I hope you can help.

Figuring out fillament grinding can be a bit tricky, but it basically comes down to tension of the idler springs, and flow of plastic in the end. You ban basically think of the hot end like a cake decorating bag. Molten plastic comes out the pointy end, there is a reservoir of melted plastic in the middle, and at the cold end, Solid plastic pushes on the molten plastic to push it out the pointy end. If you block that pointy end at all, it’s the same thing as tryng to drive a car through a solid brick wall. The molten fillament can’t go anywhere, so it stops. The cold, unmelted fillament also can’t go anywhere, so it stops too. THe hobbed bolt however does not stop and keeps spinning, tearing a C shaped chunk out of your cold fillament.

Your part pieces there don’t look like they are lifting off the bed at all, which can cause the surface of the part to be too close to the nozzle end. It looks like you are either printing very close to 100% infill, or you are overextruding some, which could very well cause that though. Check your fillament diameter and make sure it is set right in your slicing program. Also make sure that your new hot end has the same size nozzle that your settings indicate it should have. Some of the hexagon hotends have .40mm nozzles, so if you are trying to print with .35 settings, it may behave oddly.

Another thing to check is the idler spring tension. Too much tension can cause filament to gouge and strip like that.Too little can just let the hobbed bolt sand down sections of the fillament without feeding it through with much force. I have the space between the washers on my TAZ set about 7.4MM apart at the moment for ABS.

Also open up your extruder and check that the idler arm bearing still turns. Most of the 4’s should have had sealed bearings so it shouldn’t have failed, but if that isn’t turning properly it can drag on the fillament and cause it to strip.

You also want to make sure the hobbed bolt is comppletely clean of plastic, none stuck in the teeth or around the chamber. If the teeth are gummed up, it doesn’t bite into the fillament enough to extrude it properly.

With the printer at printing temperature, pull the fillament out of the extruder and take a look at the teeth pattern from the hobbed bolt. you should see a nice even “”""""""""""""""""""" pattern running down one side.

Also, Red ABS seems to take more heat to extrude properly than some of the other colors. I think it has to do with the components that make up the red coloring. Try bumping your extrusion temperature to 240 or even 245 since you have the hexagon hotend and see if that helps.

Will do. Thanks for the tips!

Well I changed the settings but haven’t been able to test it yet. The Hobbed Bolt keeps cutting into the cold filament. I can push the filament by hand and can even print a couple hundred mm of filament but then it always stops. At first it shoots out really fast but slows down and then stops.

Last time I pushed it through by hand I noticed the filament “looping” instead of coming out in a line.

Here’s a photo of what I mean:
https://goo.gl/photos/XfwyZ77shgREwRRz8

I’m guessing this is no longer a software question but a hardware one but… does anyone know how to take the tip off the extruder off?

I believe this is the one I have:
https://www.lulzbot.com/products/lulzbot-taz-single-extruder-tool-head-v2

What temperature are you running at? Also wondering if its over feeding and trying to push through when the temperature is not hot enough.
You did not say if this is ABS, I run mine at 250 with ABS (TAZ black) and I understand different brands and even different colors take temperatures that may need tweaked.

Sorry, I’m using the red ABS from LulzBot. I wasn’t printing last night, just extruding using pronterface. Also, speaking of pronterface. How does it know all of the settings? Does it use slicer’s config? I saw a mention of slicer.exe -config.ini or something like that (I’m not at home right now to verify). When I went to make the changes to slicer last night I got a message about an update and I also redownloaded the medium ABS config from LulzBot. The config I used (and made changes to) is not called config.ini. How do I tell pronterface to use the new config? When I launched slicer from pronterface it opened the old version.

Is there a new pronterface? Is there a path or config I need to modify for pronterface that I’m not seeing?

I swear I did research before I bought the Taz but I guess you don’t really know what to expect until you’re actually in front of a printer. If you couldn’t tell, this is my first one and I’m still learning.

I wish I could help more but just got my Mini about a month ago and still learning. I did my research and I think for the money the TAZ is a great 3D printer. The only other one I would consider is the MakerGear M2, seems as well built as the TAZ but the TAZ seems to have more up to date software and support. Either one would be my go to today.
But I am saving my money for a TAZ 6