Does ABS go "bad"?

A long time ago I got a cupcake CNC, one of the first hundred, and it was good. I recently built a prusa mendel and had a whole roll of the ABS I bought back when makerbot was new, however the hobbed bolt just chews through the stuff, I am exhausting things to rebuild on my extruder so I am starting to wonder, did my ABS go "bad" somehow, or is the ABS today different than the ABS that was first produced by makerbot?

No, I didn't leave the ABS in direct sunlight, which I know will make short work of it, but neither did I keep it in a sealed bag or anything, just rolled up in a drawer.

ABS will pick up water but not as much as PLA. But since I don't have experience with storing it for a long time, I don't know if this would be enough to explain your problem.

I had exactly the same problem. My first reel of ABS from Makerbot worked in HydraRaptor, the second did not. It seemed to be softer.

---

[www.hydraraptor.blogspot.com]

Hmm... okay. Maybe my extruder isn't borked then. I had issues with my cupcake CNC chewing up the ABS from this roll too occasionally so perhaps it was just not a good roll to begin with. I always assumed the extruder was just finnicky.

Would picking up water cause it to soften like this? Can I dry it out somehow? I am near the beach so am in a somewhat humid environment.

ultimachine sent me some free fresh PLA samples with my electronics order from them (thanks guys!) so I'll give it a shot while I order more feed stock.

John

I got a roll of bad ABS from MakerGear a while back. I talked to them about it, and they confirmed that they had recieved a bad batch.

It feels softer, but doesn't seem to melt well, resulting in jams, and chewing. Lots of chewing.

Over the years I have received the occasional "bad batch" of plastics from various suppliers. Sometimes it has been too hard, sometimes too soft, sometimes it melted too low, and sometimes it melted too high. Good suppliers will replace the bad product for free.

Yup. looks like an issue with my ABS. I put some PLA in there (from ultimachine) and it started printing up a storm.

Video of it printing:
[www.youtube.com]

pictures of the result:
[picasaweb.google.com]

I still have a fair bit of tuning to do as you can see from the gear I printed, but it is usable. I like printing yellow on the blue tape as the first layer looks just like a blueprint for the final object

John

I have 1 or 2 lb of ABS ordered from Makerbot more than a year ago, stored sealed in its original package with silica gel bags until I could finish my build. The stuff is reddish in color, much softer than the various Ultimachine's ABS samples I have received, and plays ugly with my hobbed bolt (just chews it apart instead of pushing it). The same bolt does a reasonable good job with other ABS and PLA.
So there definitely are issues with certain batches/mixtures, especially for ABS.