4 ms·

Background: I am trying to produce some ABS parts in small volume (10s of kg per day) and going crazy trying to find any decent source of information about the

Background: I am trying to produce some ABS parts in small volume (10s of kg per day) and going crazy trying to find any decent source of information about the print process. Everything seems to be based on anecdotes and if you're lucky maybe a Youtube video. Here is what I have gathered so far, in case it helps anyone: 1) print ABS enclosed in a chamber temp of a minimum 50C, ideal 60-80C. 2) use quality filament, Polymaker filament is good; issues are plastic composition and diameter variation. 3) dry the filament properly. 4) the fumes will destroy your lungs and eventually the printers themselves, so they need to be vented out, and also filtered inside the enclosure. 5) bed flatness is critical. 6) use a good bed adhesive such as Magigoo.

joshvm 1y ago
My gut feeling is that 10s of kg per day should be injection molded. Or SLS/resin printed so you can take advantage of layer speed. That's what 10x printers running at full tilt constantly, at least? https://www.reddit.com/r/3Dprinting/comments/7n0go2/my_first_batch_of_injection_molded_parts/ https://www.reddit.com/r/3Dprinting/comments/7n0go2/my_first... for an anecdote.
- owenversteeg 1y ago
  Plan is definitely to injection mold at some point, but this is for several different complex parts that will be expensive to mill molds for. The breakeven point between injection molding and 3D printing is really about the cost of the molds. Let's imagine a 1kg part. If you say 10x $1000 printers at 1-2kg/day and $10-20/kg filament then you can produce 900-1800 parts in 90 days for a total of $15-30/part. Meanwhile with injection molding you have a mold cost of $5k-50k and say $3/kg for pellets, so for 1k parts it costs $8-53/part. So if you're making a thousand 1kg simple parts ($5k mold), molding will be better. Making a thousand complex parts ($50k mold), 3D printing is better. And making five complex parts (5x$50k mold), you can do a lot of 3D printing before injection molding becomes competitive. I am also in a bit of an unusual situation because of the size of the parts: voluminous enough that shipping from the manufacturer is no longer negligible. Oh, and unfortunately can't do resin because of strength reasons. 3D printed ABS is already pushing it.
  - joshvm 1y ago
    Yeah that's tricky. I suggest Occam's razor: environmental control is likely to be the most serious factor? Any $1k printer should be able to extrude filament at the right rate in the right place, and I don't know that ABS is particularly challenging to melt. The difficulty seems to be in fume management (extraction) and the parts not warping on the bed? Or you pay a lot of money for a higher end printer and make use of a support contract where they can figure out where your parts are failing. One other suggestion would be to contract the parts out to a company like Shapeways and see if people are actually able to reliably make them in low volume, then try to replicate. May be a dumb question, but presumably you've tried to print the same parts in PLA or a more forgiving material to confirm that they are "printable"?
    - owenversteeg 1y ago
      Oh, to be clear I'm not having parts fail, I was more trying to figure out ways to increase strength, along the lines of this article. Your comment is good advice if someone has a part that's tricky to print, though, good to keep in mind.
terribleperson 1y ago
If you're printing ABS, you do not need magigoo or any special 3d printing adhesive. Forget it. Among the most useful characteristics of ABS is that it's soluble in acetone. Dissolve a portion of ABS in pure acetone (often available as nail polish remover). You're looking for something very roughly the consistency of milk. Colloquially this is called 'ABS juice'. Apply a thin coat to your bed/buildplate in the print area. I use a small amber glass bottle with a brush, but there are certainly faster ways to do this if you're doing a lot of printing every day. You now have a thin layer of ABS strongly attached to the surface of your bed. When you print ABS on top of this, it will be strongly attached to this, just the same as the layers adhere to each other. You should be aware that acetone will damage PEI. It won't instantly destroy them, but it's something to be aware of. As a hobbyist, I just dedicated one side of my buildplate to ABS and don't care about the damage. You could just as easily use a different bed/buildplate material, though, since you're adhering the prints with ABS juice. I have had success with Kapton sheets in the past. For hot-end temperatures, this is something you actually are best off figuring out yourself. To some degree, it depends on what you're doing and also your setup. Filaments generally come with a documented temperature range, but that should just be considered an initial starting point for testing. You should test print at different temperatures. The classic 'temperature tower' is a diagnostic print used for this purpose. Colder prints (to a point) will have crisper details and superior bridging. Hotter prints are stronger. ABS particularly loves to be printed hot, and when printed really hot I have found that layer failure pretty much stops occurring. ABS also abhors cooling. When testing cooling %s with a temperature tower, I found that even a small amount of cooling massively reduced layer adhesion. This does mean that if you're printing ABS for strength, you'll need to seriously limit overhangs and bridging at the design and slicing stage. Also consider that your nozzle can have an effect. It's often suggested to bump your print temperatures if you use a hardened steel nozzle. Plastic composition is definitely something to be concerned about. Polymaker is solid. My favorite brand for ABS is Atomic Filament but they're too pricy to use in large quantities, so I save it for specific projects. For just one example of how things can get off with some brands, if you acetone vapor polish Hatchbox ABS it gets a matte texture instead of shiny, likely indicating there's something in there besides ABS. Bed flatness is critical, but it's not something you should have to worry about. Good machines should have a decently flat and rigid bed to begin with, and even remotely modern machines also have mesh bed leveling features that correct for bed errors in software. It's usually not an issue nowadays. Back in the day, people would compensate by printing on a raft. I didn't see you mention nozzles. If you're printing in ABS it's unlikely to be a pressing issue, but do consider that nozzles are a wear component and some filaments are abrasive. You will eventually need to replace your nozzles, as a worn nozzle can badly harm print quality.

joshvm 1y ago

My gut feeling is that 10s of kg per day should be injection molded. Or SLS/resin printed so you can take advantage of layer speed. That's what 10x printers running at full tilt constantly, at least? https://www.reddit.com/r/3Dprinting/comments/7n0go2/my_first_batch_of_injection_molded_parts/ https://www.reddit.com/r/3Dprinting/comments/7n0go2/my_first... for an anecdote.

owenversteeg 1y ago
Plan is definitely to injection mold at some point, but this is for several different complex parts that will be expensive to mill molds for. The breakeven point between injection molding and 3D printing is really about the cost of the molds. Let's imagine a 1kg part. If you say 10x $1000 printers at 1-2kg/day and $10-20/kg filament then you can produce 900-1800 parts in 90 days for a total of $15-30/part. Meanwhile with injection molding you have a mold cost of $5k-50k and say $3/kg for pellets, so for 1k parts it costs $8-53/part. So if you're making a thousand 1kg simple parts ($5k mold), molding will be better. Making a thousand complex parts ($50k mold), 3D printing is better. And making five complex parts (5x$50k mold), you can do a lot of 3D printing before injection molding becomes competitive. I am also in a bit of an unusual situation because of the size of the parts: voluminous enough that shipping from the manufacturer is no longer negligible. Oh, and unfortunately can't do resin because of strength reasons. 3D printed ABS is already pushing it.
- joshvm 1y ago
  Yeah that's tricky. I suggest Occam's razor: environmental control is likely to be the most serious factor? Any $1k printer should be able to extrude filament at the right rate in the right place, and I don't know that ABS is particularly challenging to melt. The difficulty seems to be in fume management (extraction) and the parts not warping on the bed? Or you pay a lot of money for a higher end printer and make use of a support contract where they can figure out where your parts are failing. One other suggestion would be to contract the parts out to a company like Shapeways and see if people are actually able to reliably make them in low volume, then try to replicate. May be a dumb question, but presumably you've tried to print the same parts in PLA or a more forgiving material to confirm that they are "printable"?
  - owenversteeg 1y ago
    Oh, to be clear I'm not having parts fail, I was more trying to figure out ways to increase strength, along the lines of this article. Your comment is good advice if someone has a part that's tricky to print, though, good to keep in mind.

terribleperson 1y ago

If you're printing ABS, you do not need magigoo or any special 3d printing adhesive. Forget it. Among the most useful characteristics of ABS is that it's soluble in acetone. Dissolve a portion of ABS in pure acetone (often available as nail polish remover). You're looking for something very roughly the consistency of milk. Colloquially this is called 'ABS juice'. Apply a thin coat to your bed/buildplate in the print area. I use a small amber glass bottle with a brush, but there are certainly faster ways to do this if you're doing a lot of printing every day. You now have a thin layer of ABS strongly attached to the surface of your bed. When you print ABS on top of this, it will be strongly attached to this, just the same as the layers adhere to each other. You should be aware that acetone will damage PEI. It won't instantly destroy them, but it's something to be aware of. As a hobbyist, I just dedicated one side of my buildplate to ABS and don't care about the damage. You could just as easily use a different bed/buildplate material, though, since you're adhering the prints with ABS juice. I have had success with Kapton sheets in the past. For hot-end temperatures, this is something you actually are best off figuring out yourself. To some degree, it depends on what you're doing and also your setup. Filaments generally come with a documented temperature range, but that should just be considered an initial starting point for testing. You should test print at different temperatures. The classic 'temperature tower' is a diagnostic print used for this purpose. Colder prints (to a point) will have crisper details and superior bridging. Hotter prints are stronger. ABS particularly loves to be printed hot, and when printed really hot I have found that layer failure pretty much stops occurring. ABS also abhors cooling. When testing cooling %s with a temperature tower, I found that even a small amount of cooling massively reduced layer adhesion. This does mean that if you're printing ABS for strength, you'll need to seriously limit overhangs and bridging at the design and slicing stage. Also consider that your nozzle can have an effect. It's often suggested to bump your print temperatures if you use a hardened steel nozzle. Plastic composition is definitely something to be concerned about. Polymaker is solid. My favorite brand for ABS is Atomic Filament but they're too pricy to use in large quantities, so I save it for specific projects. For just one example of how things can get off with some brands, if you acetone vapor polish Hatchbox ABS it gets a matte texture instead of shiny, likely indicating there's something in there besides ABS. Bed flatness is critical, but it's not something you should have to worry about. Good machines should have a decently flat and rigid bed to begin with, and even remotely modern machines also have mesh bed leveling features that correct for bed errors in software. It's usually not an issue nowadays. Back in the day, people would compensate by printing on a raft. I didn't see you mention nozzles. If you're printing in ABS it's unlikely to be a pressing issue, but do consider that nozzles are a wear component and some filaments are abrasive. You will eventually need to replace your nozzles, as a worn nozzle can badly harm print quality.