Welcome to the SeeMeCNC Community

I built a Max V2 under the direction of Gene this summer. I am having my high school class build three more (begin praying)...anyhow,

After a couple dozen prints I am getting little branches or nodes of ooze on all my prints. This is what I have tried (and yes I did follow the manual, Gene...even where it told me to cut the Teflon tube in half!!):

Increased retraction all the way up to 12mm(no change)
Increased speed of non printing to 300
Meticulously measured and re-measured filament to adjust average filament size
Switched from PLA to ABS in multiple colors
Moved temp on ABS from 228 down to 210
Measured extracted filament (dead on-30mm extracted yields 30 mm)
Recalibrated plate with macros ALOT

What else should I try to stop these warts and branches? Is it possible I need a new tip? Or hot end? It constantly oozes when at temp?!

This is my first post, but I take my students to your site quite a bit. Thanks for being such a positive group!

Try seating the bowden tube in both PTC connectors, and use a cable tie or a twist tie to hold the collar "UP" and securing the tube down as far into the hole as possible. I've had this before from the tub having room to move instead of the filament retracting.

I haven't tried very hard to tune the SeeMeCNC hot end because I still have installing one of my E3Ds in the back of my mind and I do my critical stuff on my Mendel, but...

In tuning my E3D, I found retraction speed to clean up the print far better than retraction length. I'm all the way down at 10mm/s retraction, and it has dramatically improved the results. That may just be the E3D, so take it for what it's worth.

I will be using a cable tie today! I will also just my retraction speed. I assume 12 mm was kind of extreme for retraction... Is that the normal range for ABS?

Retraction should be around 2-5mm with a retract speed of around 45mm/sec. Can you post a pic of the results you're getting?

g.

Temp 218
4.5mm retraction
45mm/s
New filament @1.76
Freshly run macros and z height calibration

300mm/s non print moves
Extrusion multiplier is 1

OptimusPrint wrote:I built a Max V2 under the direction of Gene this summer.

Well THAT would be the source of your problem!

Sorry Gene, I simply could not resist a setup like that.

OptimusPrint, is that photo a part printed in ABS?

With PLA you want to slow retract speed down to about 25mm/s (not faster). ABS can handle faster retract. In both cases, with the stock hot end, 2-5mm retract as Gene stated is good. Do you have a part cooling fan? If so, that can significantly reduce this sort of stringing and blobbing. Read my post What's all this hoopla about fans? for more information and a strategy for effective part cooling.

Yes, this part is in abs. I do have the manual recommended cooling fan as well. The bridging fan is set at 100%. I will absolutely check out your post. Thank you.

FYI – Gene was a great teacher, although at times he tried not to laugh at me and failed!!

Yeah, Gene is one of the Good Guys - but don't tell him that, it might go to his head.

Slicing has a big influence too. Do you have any of the gcode files that you made early on when things printed nicely? If so, try printing those parts again and see what happens.

what slicer software are you using? Have you tried switching different slicers? I'm not sure, but on my KISS setting for white PLA, I was able to print perfect icedomes using prime(8), suck(8), wipe(2) and a 55mm/sec, but those #s seem quite high if comparing to what others have said on this post. But, the same setting will not work in Slic3r. I don't think I saw it in your list, but have you tried calibrating extrusion rate or flow rate?