Found some very useful information on 3d printing with acetal filament from Tony Lock. I plan on continuing his research on this subject once I complete my next printer build, all I have left to do is wire it up and build a hotend to with stand higher temperatures, plan on testing nylon as well.

http://blog.think3dprint3d.com/2013/09/3d-printing-with-acetal-filament.html

Also found taulman's work with nylon here

http://www.instructables.com/id/Combination-CNC-Machine-and-3D-Printer/?ALLSTEPS#step7

http://www.instructables.com/id/Combination-CNC-Machine-and-3D-Printer/?ALLSTEPS#step7

http://www.instructables.com/member/taulman/

http://taulman3d.com/

Has anyone considered a close alternative to acetal (aka polyoxymethylene, Delrin) ? There is a close cousin to Delrin which is an acetal copolymer.   I've worked with Delrin previously but not with extrusion 3d printing.  I was learning to use vacuum forming to make durable objects and initially decided Delrin had the properties I wanted.  After working with it for a few months I decided to try Acetron which a copolymer of acetal (Delrin).  Acetron has a slightly lower melting point and flows much easier than Delrin and I was able to make quite nice objects using this material.  It's physical properties are nearly identical to Delrin (slick surface, strength, abrasion resistant, chemical resistance) but I found it much easier to work with.

I would say if the electrical and resistance properties are the same or better, then it would be a good substitute for Delrin. Any idea of cost verses Derin?