On 02/23/2015 10:26 AM, Kirk Wallace wrote: > On 02/23/2015 09:03 AM, Bari wrote: > ... snip >> How are you defining fully hard? Urethane's can easily be over Shored >> D 90. > Common PVC pipe is too soft. The threads fold over with running a > fingernail over them. Phenolic is too hard, or rather brittle, the > thread peaks break off. Although this is likely a problem with the > cotton filler. > >> 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? > I need paintability to color the engraving. Bondabilty would be nice if > I need to build a complex lens holder from parts. > > I could use aluminum or brass but I would need to treat or paint them to > get a flat black finish. > > Another consideration is that the material should be commonly available > and cater to prototyping or DIY, since these will be one-off items. > > For optics I think Al is still the material of choice. 6061-T6 machines pretty well. Anodizing and dye gives a good selection of colors. Plastics tend to be softer and have a higher coef of expansion. One off's are a pain under any circumstances. :-)
Nothing is ever as easy as it is supposed to be. Good luck. dave ------------------------------------------------------------------------------ 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
