Makergear M2 Configuration

[jimc]

Yes i see those dashes too. There is a pic i posted on page 1. I confirmed that its creator showing the coasting. If you turn off coasting and do the preview they will be gone.

[jimc]

ok a little update on the bumps and blobs. i have continued to mess with my coast and retract settings to get the prints cleaner. while i had them pretty good before i also had to have the random start point turned off which made the print clean but i would have a defect line where all the bumps were put into one spot up the model. i watched the outer wall get put down over and over and what i was noticing is the blob was being caused by a very slight amt of excess plastic at the start of each line. the coasting really helps with taking care of 60% of it. what i didnt even think of though was adding a negative value into the extra restart distance setting. i tried this and set it to -.4 and it ended leaving a tiny blank spot on the start so i changed it to -.2 and its absolutely perfect. i have another item printing right now that is all curves and circles and so far i cant find a single bump, blob or defect in the surface. i will post my fff file for anyone that wants to try this. enjoy and post up your results.

high quality abs.fff

(3.17 KiB) Downloaded 270 times

[sir-mike]

Hi jimc,
would you mind to share the STL for your part? I'd like to print them for my posts.

Thanks
Michael

[jimc]

pm sent

[22MIL2DAY]

I am all of a sudden having large blobs at the start of each extrude of filament. What exactly is the setting you would suggest for the "Coast at End" parameter? I see it was off so I turned it on and will try a print at the the default 1.mm setting

[jimc]

hey mil, tell us what you are using, abs or pla? can you post up an fff config file for us to look at and see where your settings are? have you changed brands or type of filament recently? or even color?

[tmccafferty]

I am wondering if this blobbing anomaly has to do with S3d or with the M2 extruder. Early this year, I built a ordbot hadron for my grandson. The extruder that came with it was really bad so over quite a bit of time and threads on their forum, we ended up with a direct drive, Makergear drive gear, and a spring loaded bearing pinching the filament to the drive wheel. We used the J head. It was a long journey to get there, but once there, we got excellent print results. We were using slice3r. My M2 has much more of a tendency to drip than the J head. It would be good to get to the root cause...

Are any of you having the blobs using S3d with some other extruder?

Do any of you with M2s that use slic3r also getting the blobs.

I too improved my prints by using retract and coast, but the main change that improved the blobs for me was to turn off random start. I believe this is true because the nozzle has a tendency to leak and if you do random starts, it has time to leak. My start gcode has the routine to move over to the right side and extrude some plastic to insure the extruder chamber is full. By the time the head gets over to print the skirt, it has leaked enough to leave a large blob. I think the M2 extruder has much more of a tendency to leak than I witnessed with the J head.

[jimc]

well i have lurked on alot of other forums for different printer manufacturers and can say that its not just s3d and m2. i have seen guys talking about it with every slicer and many different printers. now if one is prone to being worse than the other i cannot say. really i think it a matter of testing and tuning the specific slicer to your printer. i dont use any other software other than s3d so all my efforts have gone into getting the two of them working good together. you may be right though. maybe some printers or even filament brands will require more aggressive retraction settings to gain control of the blobbing than others.

[tmccafferty]

You want the plastic response in the extruder head to be hard or crisp. Probably not the best words to describe the characteristic. What I am thinking though is kind of like getting air in the hydraulics of car brakes. They get spongy. For instance, if your hot end design was prone to trap a bubble of air, you would have to over step to get it going, and once you stop, the pressure from the bubble would keep pushing out plastic until the pressure equalizes. I have seen my hot end continue to spew out plastic after stopping stepping.

Also, if it's easy for air to get in the inlet where the filiment feeds in, melted plastic could continue to pour out of the chamber. Kind of like filling a straw and putting your thumb over the top. As long as you have a seal, the water won't flow out. As soon as you break the seal, the water pours out.

I am kind of shooting in the dark, but feel there are definitely some differences. My grandson is off at college with the hadron, so I can't really test it. I am currently traveling but perhaps when I get home in November, I can set up some definitive tests. I have some spare j heads.

Granted, if we can tweak the software to accommodate our individual printers characteristics, that's going to get us printing. Sometimes I am plagued with wanting to understand the root cause of issues.

[tmccafferty]

I have tweaked the coast and retract to get rid of most of the blobs at layer start locations. However, when you do that and try to print something like a 3mm column, it can't do it.