rcoope
Stainless
- Joined
- Sep 25, 2010
- Location
- Vancouver Canada
I had a former engineering co-op student drop by the shop tonight to make parts for her class robot project and it led me to wonder when did we stop using nylon, because it sucks, and start using Delrin? Briefly, we redesigned her part, she machined the nylon she'd been given (to save course money over Delrin), had some major dimensional problems after it came out of the vice where it had flexed, so I gave her a piece of Delrin and she did it right. Then I wasted her time with anecdotes about my experiences with nylon's dimensional changes and water absorption problems and gave her a bunch of rude things to say to the guys up at the physics department (where I came from) so it was worth it for that. Poor girl.
The thing is, when I was an engineering shop rat through much of the 90's in that department, I recall the shop mostly had nylon and acrylic, and then PEEK, Teflon, Vespel and other exotic stuff, but no one really mentioned acetal that I can recall. The special thing in physics though is that much machining is related to vacuum systems and Delrin is not a good vacuum material due to out gassing. So I was wondering if people can recall when it became a common engineering plastic and were we just old-school or just very vacuum-centric?
The thing is, when I was an engineering shop rat through much of the 90's in that department, I recall the shop mostly had nylon and acrylic, and then PEEK, Teflon, Vespel and other exotic stuff, but no one really mentioned acetal that I can recall. The special thing in physics though is that much machining is related to vacuum systems and Delrin is not a good vacuum material due to out gassing. So I was wondering if people can recall when it became a common engineering plastic and were we just old-school or just very vacuum-centric?