On 02/23/2015 10:46 AM, Kirk Wallace wrote: > I am using this site as a reference for making some telescope eyepieces: > http://home.fuse.net/astronomy/ > > Larry chose to use urethane to make the blanks for machining. My > experience with urethane is that recipes range from rubbery soft to > pretty darn hard, but not fully hard. I need something that can take a > .6 mm pitch thread and stand up to assembly cycles. PVC pipe is the > wrong color, threads okay, but the threads smear easily. Acetal works > very well, but can't be bonded or painted. Polyester resin might work. > I'm also considering injection molding blanks from PLA. > > I'm wondering, are there forms of urethane that have the same > characteristics as acetal? Are there other materials that would be better? > > How are you defining fully hard? Urethane's can easily be over Shored D 90.
Acetal/Delrin comes in many varieties. What characteristics do you need and what would you want different, e.g. need the machine-ability and flexural modulus but you also wish to bond to and paint it? -Bari ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
