The largest bar stock I've seen for Delrin is 6". With a little more information it might be possible to recommend another material to replace Delrin.
Depending what you are trying to accomplish with the prototype you might look a machinable waxes and other material offered by the likes of Freeman Supply, Machinable Wax, and Calwax.
Freeman Supply has a good cross section of pattern and prototype materials.
Forgot to include different materials in the form of tooling boards. One needs to look around as many of this type material can be laminated to get what size you require.
Here are just two of many suppliers.
Mcmaster.com has 8" dia Delrin but only in 6" length or Acetal copolymer in 12" lengths. As well as many other plastics (Acrylic/PVC/Nylon/Polycarbonate in 8" dia rod.
Delrin is acetal homopolymer. Co-polymer has slightly different properties being mainly slighter better mechanical properties but slightly poorer chemical and thermal stability.
Depending on the requirements you have not disclosed, cast nylon might also be an alternative, especially if it is filled with some fibre.
Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
According to "Engineering materials" 8th edition Budinski, page 152:
"The homopolymer has higher strength than copolymers, but the copolymers are more stable at elevated temperatures; maximum continuous use temperatures are as high as 220F (104C), compared with 195F (90C) for the homopolymer."
Or am I misunderstanding you?
Adriaan.
I am an Engineer/part time student (Mechatronics) from South Africa.
Advice from lecturer: "Be warned - when you go into industry your boss will give you a thousand things to do and he wants them done yesterday!" So far he is right...
