I am having some issues printing a Marvin. He is having a blow out where the legs meet the torso.I am using a FFCP with glass bed, the material is ABS with 110F bed and I think around 230-240F. I also use the simplify3D slicer and use the default setting for a high quality print. Any kind of help would be appreciated. Right now Marvin looks like he had a bad burrito.

another view.

Hello @rcox44!

ABS is notorious for being problematic with bridging, which is what happens here when your printer tries to connect the Marvin’s two legs together. Essentially, it’s printing in midair, with nothing supporting the hot filament under it, and the hot extrusion does not like that very much so it curls and forms a rather unsightly mess. But I really don’t think this is your problem, as much as excess heat is.

When you print something as small as Marvin at a very high resolution, especially with ABS, you are going to have heat issues. Each layer really does not have time to cool before you print another one on top of it, and the resulting heat creep makes it very difficult to get a clean print. I would suggest trying to print a couple Marvin’s simultaneously (4 is my usual go to) and see if that solves your problem. If it does, you know the print layers are simply staying too hot for too long. I wouldn’t suggest lowering print temperature, as that can cause other issues, and your temperatures seem to be right around the point ABS performs best.

You are dealing with bridging/overhang and small layers. First place to start when dealing with overhangs is getting the temp tuned for your material. You want it just hot enough and no more. As the layers get smaller they take less time and you are printing onto material that is till soft because the previous layer hasn’t cooled yet. I use slic3r which as options to slow the print down & adjust cooling when a layer print time is below a given threshold. The only other way would be to print more than one at a time and spread them out on the build plate so that the travel between the them gives the layers more time to cool.

-Jesse

Thanks for the reply guys, I am going to give it another shot tonight with 4 marvin’s thrown at different quadrants of the bed. I tried it the other day but had some issues with the print jumping off the print bed.

I printed 4 last night. They turned out much cleaner than the first go around. Still having a little issue with the overhangs. I’m going to slow down the print a little in the software and drop my bed temp by about 5 degrees.

We had almost the same problem while printing the marvin for completing our hub. Are you using an active cooling fan on the part? Usualy i dont use a fan directed on the part with ABS but with small parts like these its important to have active cooling, otherwise the layers are still to hot when you apply the next one on top and stuff will get messy. Try this and maybe your results will get better. Otherwise try to open up your FFCP, maybe this will bring enough cool air to the part. There are a shitload of fanducts available for the FFCP on thingiverse. Also look for the Talk post on 3Dhubs that give you some tips for printing out your marvin. This helped me allot. And one more thing you can try is to print two marvins at the same time but then at de most right and most left position, so the layers have way more time to cool before another one is applied.

Hope this helps.

Cheers,

Lenn - physical_file

EDIT: Because of some reason I didnt see that other people allready replied, and gave you almost the same replie as me, so my post wont be as usefull but goodluck anyhow.

I had similar issues until I started using a fan (yes, on ABS). You only want the fan just ticking over, I use 10% power, obviously this is different for every printer. You definitely need a fan to do the ring on his head, mine is cranked up to 50% on layers that take less than 8 seconds. It works well for me.