ABS Balls Up at Extruder

This may be duplicated but I am so frustrated and I don't feel like spending hours searching forum.

I have the i3 printers and the build went well (with the exception of the chrome rods insertion for the Z Axis but got passed it). It all went together and adjusted okay for the most part. leveling the bed was a real PITA and I am still readjusting to resolve my issue which is the extruded plastic (using ABS) is balling up at the extruder. I have spent 4 days trying to get this work and out of 40 or so attempts to print a small chain link it has only actually started to print on the bed 3 times and each one of those failed with balls of plastic on the extruder before the first layer finished. I have searched the web and tried all kinds of solutions, including glue on the bed. I did have some issue with the left side of the Z Axis sticking a bit but tried to fine tune the level of the left side and I added 2 4 oz weights to help insure it moved down when the axis was lowering. So far no joy! I have adjusted the heat settings and layer parameters in the slicer. I am tired of trying to level the bed and I also find that when I get the corners adjusted per the config manual the center of the bed glass does not seem to be correct (that one really confuses me).

Any help or suggestions would be greatly appreciated!!

Simba

Have you calibrated extruder?

Good question! Yes, quite a few times. I just talked with someone I work with that has the same printer and he may have identified something that may be an issue. When I set up the software to configure the printer parameters I saved the settings as indicated. I may not have (and probably didn't) selected those settings in the slicer configuration and the printer may be using the wrong settings. I hope this is the issue because I am anxious to get to printing.

If you have the eeprom enabled, it will use those setting in preference of what you change in the config.h file.
send the printer the following code
G502
G500

this will read the config and store the settings in eeprom.

What temps are you using for the bed and the hot end ?
You may be printing the 1st layer slightly to high off the bed.

Thanks for the information!

For the extruder I am using 230 for first layer and 200 for second. The bed temp is set to 70 for both first layer and subsequent layers. I have tried the default .2 with .1 for the first layer as well as .2 for the first layer.

Edited 1 time(s). Last edit at 02/06/2017 11:47AM by Simba028.

I would have thought that a bed temperature of 70C for ABS was a little on the low side. The general recommendation for ABS seems to be 100-110C, although I have printed ABS OK with the bed at 90-95C. The balling up of the filament is typical of poor bed adhesion. It can also be caused by trying to extrude the filament at too low a temperature, so that it is not fluid enough to adhere and spread out. Try increasing the extruder temperature by another 5 degrees. I would also leave the extruder temperature alone for subsequent layers, if the filament is not fluid enough it may be easier it to tear the first layer off the bed rather than spread out.

Your problems with levelling the bed glass would suggest that you glass is not flat.

Edited 3 time(s). Last edit at 02/06/2017 12:08PM by Supermec.

Thank you, I will give those values a try. I feel like a dolt for not considering the difference for PLA vs ABS.

The 1st layer needs to be squished slightly onto the bed to help adhesion, maybe print 1st layer at 0.25 with an extrusion width of 130% for 1st layer. then 0.2 or 0.1 for susequent layers.

When I'm printing generic abs. I usually have to go for about 240 C for the nozzle.
70 is minimum on the bed. Works if one uses abs juice on the bed. But its nasty stuff.
Higher bed temp and enclosure is better agains warping.

Happy printing!

This has been great input and I appreciate it very much! I have a feeling I will get a good print today when I give it another try.

Tell us how it went!
Its always a bit challenging to get all settings good. To get perfect, takes just more work.

No joy! I finally found that I had to edit the GCode to set the temps properly. I adjusted the bed again and tried a print using 105c for bed and 240c for the hot end. Still balled up. I thought I might have an issue with the nozzle so I changed it and did a test extrude and it looked okay. Tried again with same results. I coated the bed with a slurry of elmers glue and water but it made no difference. I will be getting some PLA tomorrow and will try that. I am sure I am doing something wrong... just not sure what.

What bed material are you tying to print on? Glass, blue tape, PEI?

Also is your bed clean? Even oils from your skin can affect a print from sticking. Trying cleaning the bed with an isopropyl alcohol to remove any oils or dirt. You should also clean any ABS off the nozzle, ABS like to stick to ABS so clean the nozzle with some acetone to remove any plastic that stuck on

You could also try a lower first layer height, what layer height are you trying to print with now?

Hm.
Always annoying when stuff dosent work..
could you take som picture. Its says more than thousands words.
Does temeratures seems to be correct to the set value?

I finally had success and I think I have a better understanding of my issues. The fault is all mine, not the platform/printer so I hope this helps someone else. Up front let me say I appreciate all of the input I received in this thread. First of all, I was using the wrong material for the temperatures I was set for. I purchased ABS thinking I was getting PLA but that was just a dumb mistake on my part. I have since ordered PLA and a friend loaned me some PLA to try. I believe I was balling up at the nozzle due to the setting I was using for the first layer. I was set for the wrong height (going too low when I needed to be higher). The nozzle itself was interfering with the PLA as it was laid down. This was strictly my issue with not understanding what I was doing - this is a bit humbling since I consider myself a technical person. As I think about the situation it should have been clear to me what was actually happening. Another issue I caused was that I was using a model that was already compiled and I didn't understand why the settings for the printer didn't seem to make any difference when I set and reset them. Well, the answer to this dilemma was that I wasn't slicing the model and therefore the changes were not being incorporated in the GCode. I finally realized why the settings were not being used and it finally hit me that the model I was using did not allow me to perform a compile. I did figure out how to modify the GCode manually. I did finally use a model that I could slice and my settings were working. Even though I do some programming on my own I was intimidated by changing any GCode but I got over that . I am now convinced that by changing the temps I could also print with ABS though I haven't done that yet.

On a related note, I found that my desk where the printer is sitting has an issue, the level is not consistent across the surface and the printer could flex which could cause the bed to flex and become unlevel as weight shifted during operation. I resolved this issue by purchasing a 3/4" piece of Oak plywood, which I verified was level across the surface, and cut to 18" by 16.5" and attached the printer to the board using 1/2" conduit clamps with 1 wood screw each. The clamps are on the bottom threaded rods near the outer ends on the inside at both ends of the assembly. This has resolved the flexing and provides what I think is a better way to transport the printer should I want to move it. I have seen pictures of someone carrying the printer by the upper plexiglass piece and I cringe at that concept.

For the record I have the reprap Prusa i3 Mk2 printer.

Edited 2 time(s). Last edit at 02/09/2017 02:40PM by Simba028.

Good to hear!
Usually there are a few small things that makes things go wrong.
I for sure know about that..

Im on to make a plate to my Anet too. Well after some other projekts on it..
You sure you have a original prusa i3 mk2?

Not sure. But I think they only is available with a alu frame?
My Anet has a acrylic frame. That is flimsy like nothing else..
Rods are anything else than straight.. But it actually works. But needs ALOT of mods and attention.

My bad... I have the V2