Thanks! ;-) I would like to provide more text on the site, but it takes a lot of time to write something right.. So I try to make more photos ;-)
http://dalibor.farny.cz/custom-stems-first-attempt/ Dalibor 2012/6/17 kay486 <luckyl...@gmail.com> > I really like the update on your page! Yove made quite some progress :) > > > On Sunday, June 17, 2012 8:53:26 PM UTC+1, Dalibor wrote: >> >> Nice information about making stems are in the Roth's book noticed >> recently here.. "Vacuum sealing techniques", for those interested in this >> book, let me know outside, I will post link.. >> >> I have already got a small test mold made from graphite, 13-pin.. My >> original intention was to arrange some kind of furnace in microwave oven >> and melt the glass directly in the mold with dumet wires inside.. But no >> luck yet, I am able to heat a piece of the carbide to 1000C, but the power >> is to small to heat all the mold with glass. Another thing is, that at this >> temperature, the graphite reacts with oxygen producing CO2 and degrades.. I >> think 10 cycles is maximum for one mold. The furnace with controlled >> atmosphere (nitrogen, argon, CO2 ..) would be the best.. I am going to ask >> my friend to test that process in their lab, he has a special tubular >> furnace able to go above 2000C ;-) >> >> I am preparing some short blogpost about my fail ;-) I will publish it >> tonight. Except that, I had also some small success, sealed argon tubes.. >> that post is already done: >> >> http://dalibor.farny.cz >> >> Dalibor >> >> 2012/6/17 Dalibor Farný <dali...@farny.cz> >> >>> Hi John, >>> >>> are You sure that only gravity is enough for the glass to flow to the >>> mold? At what temperatures? I tried 800C and no luck.. >>> >>> Dalibor >>> >>> >>> 2012/6/17 John Rehwinkel <jreh...@mac.com> >>> >>>> > How exactly would you proceed making - say - 13 pin tube bases? You >>>> need a lot of temperature for that and precisely formed tools. So far this >>>> is nothing I can see myself doing in the near future. I know a person who >>>> makes his own (borosilicate glass) sockets, I might be able to adopt the >>>> principle some day. >>>> >>>> The tool part isn't too tough, just carve it out of graphite with pin >>>> recesses. CNC machining would be the way I'd go, but back in the day it >>>> was done by reading scales on handwheels, and obviously it could still >>>> be done that way. Once you have your graphite mold/pin holder, >>>> get some nice 3-part pins and lead glass tubing of an appropriate >>>> diameter. Lead glass is the way to go here - it liquifies enough to >>>> gravity flow into molds like this. Slice off rings that have >>>> sufficient glass to make your bases, drop pins into your mold, put the >>>> glass ring >>>> around them, and melt the whole shebang. For extra niceness, you can >>>> have an upper mold half that forms little mounds of glass over >>>> the pins themselves and flattens the rest of the base into a disc. Let >>>> it cool, and violà! The first one will be a real bear, as you have to >>>> make the molds determine the amount of glass, temperature to use, etc. >>>> But once you have the molds made and the procedure down, >>>> you can knock out additional bases fairly easily. >>>> >>>> - John >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "neonixie-l" group. >>>> To post to this group, send an email to neonixie-l@googlegroups.com. >>>> To unsubscribe from this group, send email to neonixie-l+unsubscribe@** >>>> googlegroups.com <neonixie-l%2bunsubscr...@googlegroups.com>. >>>> For more options, visit this group at http://groups.google.com/** >>>> group/neonixie-l?hl=en-GB<http://groups.google.com/group/neonixie-l?hl=en-GB> >>>> . >>>> >>>> >>> >>> >>> -- >>> Dalibor Farny >>> http://dalibor.farny.cz >>> >>> >>> >> >> >> -- >> Dalibor Farny >> http://dalibor.farny.cz >> >> >> -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To view this discussion on the web, visit > https://groups.google.com/d/msg/neonixie-l/-/audInw3BesQJ. > > To post to this group, send an email to neonixie-l@googlegroups.com. > To unsubscribe from this group, send email to > neonixie-l+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/neonixie-l?hl=en-GB. > -- Dalibor Farny http://dalibor.farny.cz -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
