Hi everyone! Im having problems with having my printer verified due to the ring on top of the marvin not printing good enough. Atm, Im printing PLA at 100um, 190C, 30mm/s, but it still looks like a weird mess. The order in which I printed the marvins in the picture is left to right, with the last marvin not printing a ring at all… Might my rectraction of 4,4mm and coasting of 1,5mm be the problem? I didnt have time printing a marvin with these features disabled, but Im afraid I will spend another hour printing another (count is at 7 or something) failed marvin, so wanted your opinions 
Thanks in advance!
The layers of the ring are very small so they print very fast but each layer needs to cool before printing the next. You need to slow down (some slicers have an option to slow down for small layers), increase/upgrade cooling fan, and/or print more than one Marvin at a time so there is more time between layers.
Thank you for your reply!
Unfortunately, I tried all of your suggestions, and my Marvin is still not adequate 
I made 2 processed in S3D where the top is even slower (20mm/s) and has less retraction, so have more filament coming out.
I guess I shouldnt print at 100um (deleted it from my printer)
First thing is to print at .2 until you get a good one then you can start reducing the layer height. A thin layer like that brings its own challenges and when you throw Marvin in on top of it you are going to struggle.
Heat is the biggest problem. The simplest thing is to print three or four at a time.
You don’t say what printer or slicer but your retraction seems extreme.
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Im using S3D with a TEVO tarantula.
Considering Im only printing functional parts and not really sculptures, I find it frustrating to keep printing Marvins that are just fine for my type of printing 
Im gonna try 200um, but Im not gonna spend too much time on it anymore 
my printer will probably only be online for about a month, and given there are quite some printers in the area, Im probably spending more time on these Marvins than I will on orders 
Thanks for the help though!
Use .200 layers and 15mm / second and it should work.
I’d say you’ve got that the wrong way around myself - I only print structural parts really too, and I’ve had to make all sorts of mods to my printer to make it far more accurate than it needed to be just for sculptures - sculptures don’t matter if they’re out on accuracy here and there because it tends to be relative and blends in anyway. An arm that is 1mm out of place and stretched a little on a sculpture is un-noticable, whereas it can render a structural order completely useless.
If you are only printing “functional” parts then why are you wasting time printing at .1 layer heights.
Good luck.
I would never print a Marvin with layers larger than 100micron, especially for a customer.
Retraction only prevents ooze. Unless there is something wrong with your extruder/settings, lowering retraction doesn’t make “more filament coming out.”.
Is your extruder calibrated (stepps/mm & temp)? Have you modified the cooling? Is your nozzle clean? What size nozzle are you using (I wouldn’t use anything larger than 400micron)?
Posting all your settings would be helpful. Looks like you’re getting close.
99% of what I do is functional parts and I almost always print at 100micron or less. Even on large parts, I usually still do perimeters at 100 micron.
Functional parts often need to fit together and have tight tolerances. In my experience, 100 micron is best for dimensional accuracy and minimal finishing/post-processing.
I do agree with Wirlybird about mastering the 200micron first. That’s good advice. Most frustration in 3D printing comes from users trying to run before they crawl.
If you’re only having issues with the top ring, then cut your model so that you’re only printing the top of Marvin’s head and above. This will speed up the experimentation process, so you don’t have to wait for the rest of Marvin to print. I do this all the time if I have a tricky model, cut out the bit that looks problematic and tune while just printing that small part.
