Hi guys, this is the first time trying to print a Marvin, so far I have printed 5, the last one came out better but I still don’t know how to fix those overhangs. I’ve tried printing in cooler temperatures and speeds, the last one was at 200°C and 30 printing speed. I have a Maker Select / Wanhao i3 with the Z-Brace mod. Help is really appreciated 
https://imgur.com/a/OSE97
https://imgur.com/a/r922z
1 Like
Is this print in PLA? If yes, do you have your cooling fans on? Turning them on will make a huge difference with overhangs and bridging!
1 Like
Yes, sorry I forgot to say it was PLA, and yes I’m using the cooling fan on maximum
2CNK
4
From my own experience (this is with PLA) the wavy banding on the bottom half of Marvin is due to being too hot. Same with the limp keyring loop.
If this was my print, I would drop my extruder temperature by 5C at a time, print a Marvin each time, and observe the results.
If you have any extra cooling fan available, turn it on.
Also - this tip was from someone else and helped me - print 3-4 marvins on the bed. Printing the other marvins will give the layers more time to cool off in between layers without a hot nozzle on and near them.
If there were still goopy overhangs like the eyebrows after all that, I would try to increase retraction a bit - but honestly your retraction seems pretty good already since the sharp sides of the helmet/face area don’t have any blobbing or zits. (That wasn’t the case for me)
Good luck!
1 Like
That’s what I did, dropping the temperature 5C each print but at 195C the print seem worse (that’s the 3 Marvin from left to right) but I can try again, I think I will try first printing the 3-4 Marvins seems like a great idea. Thanks for your response 
Hmm, interesting. I’d actually try bumping up the print speed you’re using; 1,800 mm/min (I’m assuming that the 30 you referenced for speed was in mm/sec) is definitely at the low end for PLA speed. Printing that slowly means the hot nozzle is in contact with each layer for quite awhile, heating it up further and possibly too much for the cooling fan to compensate.
Try bumping up the speed to around 50-60 mm/sec and see if that helps.
1 Like
Huh… I didn’t thought about that, I thought that by printing slower I would get better results, I l will definitely try that!
What about the travel speed? (Non printing speed)
Printing slower does improve quality to a point, but going too slow results in much higher heat build-up than you’d normally experience and this is bad for small parts. With larger prints, you can go as slow as 10 mm/s and experience few problems because they have the volume to dissipate heat away from the fresh layer quickly, but this isn’t the case with Marvin. He is pretty tiny, so the longer you have the nozzle hovering around on the part, the more it will heat up. That heat really has nowhere to go so you get curling and sagging layers. Heat transfer is a fickle beast, and 3D printing is the epitome of that.
As 2CNK suggested, a nice workaround for this is to print 4 Marvins at once. This essentially triples the cooling time for each layer of each Marvin so you get much better results regardless of print speed.
Travel speed isn’t as important so long as you don’t go so fast the printer is jerking around with the movement.
You have 2 seperate issues going on here.
First, the tops of the eyes and the top of the opening of the helmet need more distinct and smaller supports.
The loop on top is flat out a cooling issue. Your slicer software should have a cooling setting, which will lower the print time between layers, which will let the previous layer cool while waiting before it prints the next layer.
I think this is the best my printer can do 
Enza3D
11
Do you have an infared thermometer by any chance? That still looks like a temperature issue to me, especially the curling around the eyes/eyes themselves. If you do have one, I’d suggest measuring what your hot-end is actually at when you’re printing. The maker selects/i3s are notorious for improper temperature readings, so for all you know, it could be printing much hotter than you’re setting it at. If you don’t have one, I suggest picking a cheap one up from Home Depot or online; it shouldn’t be more than $20 and it’s an invaluable tool to have for diagnosing temperature issues.
What brand of filament are you using? The way your print is curling is identical to what happens when I first print a new color of PLA/PHA with my printers. I have to adjust temperature per color; blue PLA/PHA prints at different temperatures than black PLA/PHA does, so it usually takes a Marvin or two to get everything nicely calibrated.
This print looks much better than the previous ones, so don’t get too discouraged yet! Printers are finicky and it takes a decent amount of fine tuning to get it printing well, and experience to know how to fix what’s going wrong. All of this takes time to learn, and it’s hard being patient enough to learn it, but the end results are worth it! Can you post all of your settings for me? Infill, extrusion multiplier, retraction, etc.?
