I have a small part that looks incredibly basic but I’m having an issue trying to print it successfully for a customer. It is a small 2.25" by 2.25" by .5" piece that he wants printed in ABS. Problem is it has a 1/2" long, 1/16" high overhang that goes around a 90-deg corner with a lip that brings the gap down to 1/32", almost like a drip edge.
I loaded up some HIPS in the left extruder and ABS in the right extruder thinking I’ll just print it, dunk it in Limonene and we’re good (I need to print 2 each of 4 similar parts (each with similar overhangs)). Anyway, I have been trying to get a decent print but that dang overhang is killing me for some reason. I just can’t get it right.
The client is VERY concerned about the bottom of the part and needs that as smooth as possible. It actually prints very nicely on a HIPS raft, separates easily.
I have tried printing the part standing on its end as shown in the last picture below and it comes out great but doing so adds an hour to the print time and almost doubles the material usage.
I’m using Simplify3D and tweaking settings, doing a test print, noting the results, tweaking, etc. I sunk the part down into the bed a bit so it gets to the overhang more quickly. Any thoughts/ideas/tips anyone has that may help me get a successful print for this thing in ABS lying flat? Thanks…!
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I am guessing you haven’t been able to get supports to work under the overhang?
I would be happy to try also if you wanted to send the STL.
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Something I’ve done with a similar situation is load the file into whatever cad program you use, and take the empty space under the trouble area and 3D print that shape with -.02mm on the outside. Then when I print the main object I put the “empty area prints” and hold them in place while the printer uses them as a support. I then slide them out at the end. I hope you understand what I mean.
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ABS supports of the same material in S3D seem to break away easy for me. If you can manage it in HIPS even better.
Can you share a bit more info as to what all your settings in S3D look like? And specifically what kind of failure you’re getting with the overhang? It may come down to your support and bridging settings…
I do and that’s quite cleaver. Being a small, and 90-degree part I’m not sure it would work. Gotta remember that though, thanks!
I actually have been able to get the supports to work, and quite well. It is the ABS that then needs to print on top of the supports that is giving me the trouble. I have one print that was successful but dang W10 updated overnight and I hadn’t updated the selected profile in S3D. Ugh. Anyway, here are a few examples of what I’m running into:
I see what you are up against now.
How about if you make the support closer to the lip-under side and use dense supports for more coverage?
Just replied with a few pics to @wirlybird. The support is being printed in HIPS.
The overhang gaps in the model are 1/32" and 1/16".
My settings for those particular prints at the time were:
Support resolution in those pics is 1mm,
Support Infill is 50%
Extra Inflation 0.00mm
Dense Support Layers 1
Dense Infill is 70%
Horriz offset 0.20mm
Upper & Lower Separation Layers both 0
Yep, I’m using HIPS for the support. I love how easily it breaks away…
Currently trying 1 dense support layer and 70% dense infill %, and I have the vertical separation layers at 0. Considering turning up the ABS temp a bit to see if it will bond better at least when being extruded.
I print in ABS pretty much exclusively on my FFCP. I would definitely print the model more flat. Also, make sure your bed is level and your acceleration settings adjusted according to your bots f/w.
I was unable to attach my S3D FFF profile so I saved it to my g-drive and shared it…
My basic settings are 235 & 90 (right-extruder&bed temps) 85mm/s print speed, cooling fan off and I use ABS juice on the bed.
if the processes import properly, use the “ABS 020” and adjust your infill % and make sure support generation is on (Normal)and maybe change the support material resolution, I run 2.5mm on most stuff. Plus, I would use a “Helper Disc” in the corners to help with adhesion throughout the print. (attached one of my helper disc stl files)
helper_disk_small.stl (18.6 KB)
Thanks, I’ll give this a shot. I have not been using ABS juice, just letting it use the blue stuff on the QIDI bed (realizing I failed to mention I’m using the QIDI Tech 1 version). Seems to stick to the bed OK. Just that dang overhang!
Sounds like setting problem. Here is a link to my FFF files that I posted on Thiniverse for the QIDI. They will get you close. ABS & PLA FFF. Files by ChrisX35 - Thingiverse
Enjoy,
Thanks @ChrisX35…believe it or not I’m actually printing a 3DBenchy with your QIDI ABS right now!
Had trouble in the beginning with the first layer so I removed the 0.05mm z-Axis offset you added (noted that in your comments) but that still didn’t help so I set the initial layer height to 150% and the first layer width to 125% and that fixed it.
Was surprised to see you had cooling at 70%. Will let you know how it turns out. Thanks!
Believe it or not the settings work great with my QIDI but every printer is different that’s why you run test prints and tweak things accordingly. I run my fan at a reduced speed because of overcooling issues and the part will warp or split.
Good luck
Thanks. The Benchy turned out pretty good so your settings are a known quantity for me now at least with the ABS filament alone. I was going to try adding back in the HIPS on the left extruder but instead right now I’m trying the part at a 45-degree angle on its end with a brim. Doesn’t require any supports at all that way and so far the brim is holding it down. We’ll see!
cobnut
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Hi @Tech3design what I’ve done in the past with problem supports is make my own, completely solid. I’d take the part into your preferred editor and create a separate solid for the overhang space (a box and some boolean subtraction should do it), then print that bit with HIPS (i.e. don’t use any supports in S3D, just effectively dual-printing). Of course you’ll need to soak it to remove, but you’re ready for that anyway.
Good luck, looks like a nightmare piece!
Thanks for the tip, that’s not a bad idea. Two things, your user name is funny, and that last comment is so true. I was just telling my wife last night that on initial glance it looks like just a basic, simple geometric shape - easy print. But dang, that tiny little overhang has really been a PITA! If the part were larger it would be a lot easier but as small as it is nightmare is right!
Thanks again.
I want to first thank everyone who responded to my post. Everyone had great suggestions and I really appreciate everyone taking the time to try helping me out. I think I’ve solved my printing issue and am posting it as a separate comment as opposed to a specific reply.
@ChrisX35 - Special thanks to you for your QIDI FFF that you had posted on Thingiverse (@TTB_Studios - I tried yours too but it seemed to be specific to the FF and didn’t work on my QIDI - seriously appreciate your sharing).
I used that ‘QIDI ABS’ profile to print a 3DBenchy to see how it would turn out. Came out pretty good so it was a known quantity. I figured I’d just modify that to add the HIPS to the left extruder and work my way back to using both materials.
What I decided to do instead was flip the part to a 45-degree angle and see if it would print that way. I used a brim because there was almost none of the part touching the build plate but it held the part down (also set the first layer width and height up to help stick). At 45-degrees it shouldn’t need any supports at all theoretically. I also had to rotate it 90-degrees so the ridges were facing the cooling fans otherwise the far side didn’t look so hot.
Below is a shot of the final result… Still need to do a little cleanup on the parts but they actually came out pretty good I think. Again, thank you to everyone who offered advice. I really appreciate your time.
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