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Re: old parts anf stuff
James Lerch
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----- Original Message -----
From: "RON WHITE" <ron_white@...> Hi Ron,I just met a fascinating guy who owns a small vacuum I'm looking for a couple sending units to fit my Boc Edwards 1105 controller. #1 I'd love a second Penning Cold Cathode Ion Gauge, so I don't have to move the one I have between chambers :) The one I have is a Model CP25K, Part Number D14537000 If a picture would help, there's one here: (bottom image) Also, If he had a coupler for the same that would be great (so I don't have to machine a second one <G>) #2 A Pirani or thermo-couple gauge head for the same controller would be great to. Here's a couple more pictures of the controller if it might help identify it. (61KB) (96KB) On the back image above, the Coax cable attached to Slot 3 goes to my existing Penning gauge head. Slot 1 / 2, to the left, are where the Pirani or Thermo-couple gauges would attach. Thanks a bunch! James |
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Re: Ho Hum again... stir the pot, add eye of newt, double bubble, toil and trouble.
James Lerch
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From: "Ken Hunter" <atm_ken_hunter@...> James, I'm curious why you are sticking to a filament above the glass andThe new 25" chamber will be in a vertical orientation, to avoid the above mentioned problem! In the mean time my 11" chamber, vertical coating is the only way to go unfortuantly. On the plus side, I've never had a "Sputter" problem when evaporating (Ie stuff Flying off the tungsten). With the existing 6 point layout, drops of molten Al are also not a problem, as they would miss the mirror (as long as I keep things realativly centered). Another odd thing is, since I have 6 points, I don't have to put very much Al on each tungsten filament, consequently I have NEVER had a drip problem with the new layout :) Take Care, James Lerch (My telescope construction,testing, and coating site) "Anything that can happen, will happen" -Stephen Pollock from: "Particle Physics for Non-Physicists: A Tour of the Microcosmos" |
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Re: Vacuum / Neon questions
Ken Hunter
Hi Hans and welcome to the Vacuum Experimenters Group.
I think you will have a lot of fun building your NIXIE tube! You might want to check into one of your local NEON SIGN companies to see the process first hand if you've not seen it before. If you can get to talk to one of the technicians that makes the signs, he can show you how to attach ready made "thru-glass" connections to your base and also show you how to do the vacuum part. They will have NEON and feedthroughs you can buy and torches that you can see to get an idea of what you'll need. A few minutes in their shop will answer a thousand questions. Once you do that we can help walk you through the process. Ken Hunter --- In VacuumX@..., "Hans Summers" <Hans.Summers@t...> wrote: see on my webpage, seeSeems fun to have a go at building my own nixie tube, as much aspossible from commonly available items and without special or expensiveWeston's 1968 book "Cold Cathode Glow Discharge Tubes". At the moment Ihave a large number of questions some here might be able to help with.square of ordinary glass sheet, fixed to the jar using vacuum cement. 4nixie tube to whatever it needs to be bolted to, using plastic bolts ofglued using ceramic cement. The anode mesh will be made from fine wireit? of 5 10,000uF in parallel), based on previous experience welding aft spark). Seems more than sufficient to weld a couple of wirestogether. glass tube through the base plate.in the neon? How about a suitable getter material to soak upremaining oxygen? Where can such be obtained, and is it really necessary foran experimental project? The tube won't have to exist in a commercialpump? What kind of blowtorch is required to seal the glass tube when thetube and/or baseplate or is any household glass Ok?small quantity)? How about a suitable vacuum cement with low outgassing |
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Re: Ho Hum again... stir the pot, add eye of newt, double bubble, toil and trouble.
Ken Hunter
James,
Thanks for the GREAT INFO... It's going to take me a while to digest all that and check out the links but it's nice to have on file here to refer back to! OK on your diff pump size... I thought from your photo of the mobile coater that was about the size you had but it could have also been a 4 inch pump in which case I might have been able to help increase the size of your system a bit. I'm curious why you are sticking to a filament above the glass and taking a risk of sputter damage or as before, drops of molten metal hitting the glass? My tank is 24 inches diameter and approx 30 inches tall. There's a photo in my junk folder and I'm still not into a house yet so have made NO PROGRESS in regards to getting anything done. Maybe by Christmas??? Again, thanks for the info for the group! Ken Hunter --- In VacuumX@..., "James Lerch" <jlerch1@t...> wrote: ----- Original Message -----about 10" above a 10" diameter mirror. It took two consecutive evaporative runsto get an opaque coating all the way to the edge. With just one run, thecenter ~30% was opaque and the last 1/4" of edge made for a nice beam splitter(maybe 75% coated.)grinding, polishing, and figuring to "erase" the drip damage (It's soo nice that glassis so forgiving!) I re-built the chamber to a multi-point evaporativesetup (with the filaments out by the edge, so if another drip happened it wouldmiss the mirror!)evaporative simulator. I've had great results playing and working with it.If you haven't seen it you can download a copy from here:3 various radius evaporative rings, with as many filaments as you'd like oneach ring. (Careful! this can turn into a serious CPU Hog!)code to figure out the layout for the In-Situ aluminization of the 6.5m MtHopkins MMT mirror, See link for some Fascinating reading!! <g>www.harvard.edu/cfa/oir/MMT/www.mmto.org/MMTpapers/pdfs/tm/tm03-8.pdf and if you refer to the above figure 3, they report a 1.6nm deviation, and my simshows a 1.8% deviation, which turns out to be 1.69nm with a coating thicknessof 94nm (their target). OH, the reason for the slight difference? I model themirror as a sphere, since in usual ATM hands the difference in Path Lengthbetween a sphere and a parabola is really small :) Here's a screen cap of mysimulation results: offset followinghalf way and the mirror rotating to reduce the filamentYou can use my simulator to simulate this arrangement. Enter the wait for an answer)well means your going to need a fairly tall chamber!your chamber isThat is what I'll probably do in my chamber for theI know for certain a single point doesn't work to great unless really long.mirror surface, works really good on 10" F/5 there abouts.mirror closer to filaments) I can actually add a "little" extra correction to amirror. Even more amazing is Robo is able to measure the change in figure, andit agrees with the near field simulations (were talking a VERY small change, likea 2nm or so!) which only 3 ofHow big is your Diff pump?6" inside diameter, with 4 electric heaters at the bottom, of the heaters work (I burned one out thinking the pump was 220V,when it was only 110v (ooops!). Still pumps my 12"id x 11" tall chamber down inunder a minute (once the rough pump is done) I may have to replace that badheater once I get the Larger chamber finished, but I'll wait and see :) |
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Vacuum / Neon questions
Hans Summers
Hi
I want to build my own nixie tube. I built a nixie clock you can see on my webpage, see . Seems fun to have a go at building my own nixie tube, as much as possible from commonly available items and without special or expensive equipment. To assist in this endeavor I have a copy of G F Weston's 1968 book "Cold Cathode Glow Discharge Tubes". At the moment I have a large number of questions some here might be able to help with. Plan so far is to use an ex-English Mustard jar, measuring 5 cm in diameter and 8cm high. This will be inverted and form the top and sides of the homemade nixie tube. The base will be made from a square of ordinary glass sheet, fixed to the jar using vacuum cement. 4 holes in the corners of the square base can be used to bolt the nixie tube to whatever it needs to be bolted to, using plastic bolts of course. Cathode digits will be made from nickel wire if I can find it. The internal supporting structure from glass or ceramic rod, again glued using ceramic cement. The anode mesh will be made from fine wire wound helically around the supporting structure. Holes drilled in the glass base will take the connecting wires, cemented using the vacuum cement. Alternatively is it possible to melt the glass baseplate with a blow torch and push wires through it? The connecting wires will be welded not soldered to the digit cathodes. For this I plan to use a 50,000uF 100V capacitor (bank of 5 10,000uF in parallel), based on previous experience welding a screwdriver to the bus terminals on shorting the capacitor (and 3 ft spark). Seems more than sufficient to weld a couple of wires together. Vacuum generation and subsequent neon injection will be via a glass tube through the base plate. Does anyone know what degree of vacuum is required before putting in the neon? How about a suitable getter material to soak up remaining oxygen? Where can such be obtained, and is it really necessary for an experimental project? The tube won't have to exist in a commercial environment with a 100,000 hour lifetime and guaranteed specifications. Can the vacuum be generated with a simple homemade piston type pump? What kind of blowtorch is required to seal the glass tube when the gas is ready? Is a special kind of glass required for the glass tube and/or baseplate or is any household glass Ok? On the subject of materials, where can neon gas be obtained (in small quantity)? How about a suitable vacuum cement with low outgassing properties? Any comments/suggestions welcome Hans |
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Re: Ho Hum again... stir the pot, add eye of newt, double bubble, toil and trouble.
James Lerch
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----- Original Message -----
From: "Ken Hunter" <atm_ken_hunter@...> Hi James...Hi Ken and All <g> Have you done any "fall-off" experiments to see just how much ONEWhen I first started playing with my chamber I had one filament about 10" above a 10" diameter mirror. It took two consecutive evaporative runs to get an opaque coating all the way to the edge. With just one run, the center ~30% was opaque and the last 1/4" of edge made for a nice beam splitter (maybe 75% coated.) After the "catastrophic drip" incident, and subsequent re-grinding, polishing, and figuring to "erase" the drip damage (It's soo nice that glass is so forgiving!) I re-built the chamber to a multi-point evaporative setup (with the filaments out by the edge, so if another drip happened it would miss the mirror!) To help me figure out the filament layout, I wrote a near field evaporative simulator. I've had great results playing and working with it. If you haven't seen it you can download a copy from here: (9KB Exe only) The above code can simulate mirrors upto 24" in diameter, and have 3 various radius evaporative rings, with as many filaments as you'd like on each ring. (Careful! this can turn into a serious CPU Hog!) BTW, my simulator is based on the work of Jim Hill who wrote the code to figure out the layout for the In-Situ aluminization of the 6.5m Mt Hopkins MMT mirror, See link for some Fascinating reading!! <g> I ran my near field sim on their data (Scaling everthing down), and if you refer to the above figure 3, they report a 1.6nm deviation, and my sim shows a 1.8% deviation, which turns out to be 1.69nm with a coating thickness of 94nm (their target). OH, the reason for the slight difference? I model the mirror as a sphere, since in usual ATM hands the difference in Path Length between a sphere and a parabola is really small :) Here's a screen cap of my simulation results: (119KB) I've also seen 24 inch mirrors done with the (one) filament offsetYou can use my simulator to simulate this arrangement. Enter the following Mirror Radius = 300 Mirror Roc = "whatever your test subject is" Ring 1 # of evap points = 10 (or more, depending on how long you want to wait for an answer) Evap point Rad = 150mm (50% radius) Height of EVP (height above mirror center) Ring 2 & 3, set # of evap points to zero. BTW, I played around with this, and to make it work reasonably well means your going to need a fairly tall chamber! That is what I'll probably do in my chamber for theI know for certain a single point doesn't work to great unless your chamber is really long. So far, my 6 points with a radius of 140mm about 120mm above mirror surface, works really good on 10" F/5 there abouts. What's interesting is if I change the height difference (move mirror closer to filaments) I can actually add a "little" extra correction to a mirror. Even more amazing is Robo is able to measure the change in figure, and it agrees with the near field simulations (were talking a VERY small change, like a 2nm or so!) How big is your Diff pump?6" inside diameter, with 4 electric heaters at the bottom, of which only 3 of the heaters work (I burned one out thinking the pump was 220V, when it was only 110v (ooops!). Still pumps my 12"id x 11" tall chamber down in under a minute (once the rough pump is done) I may have to replace that bad heater once I get the Larger chamber finished, but I'll wait and see :) Take Care, James |
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Re: old parts anf stuff
--- RON WHITE <ron_white@...> wrote:
What Size diffusion pump do you need / or how largeI will use the sistem for cathode ray tube recovery, and the diffusion pump I need is about 4 inches in diameter (200 liters/second?). Respect to chamber, the bigger crt is 36" wich coul be considered as a chamber of 6 cubic feet. Respect to gauge, I need to measure up to 10-7 mm Hg. I think Ion type would be addecuate. I will appreciate your answer. ===== Alberto Gasparini Perito Moreno 1032 Godoy Cruz (5501) Mendoza ARGENTINA telefono 0261-422-0923 __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software |
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Re: Ho Hum again... stir the pot, add eye of newt, double bubble, toil and trouble.
Ken Hunter
Hi James...
Have you done any "fall-off" experiments to see just how much ONE FILAMENT will coat? The TV tube coating machine I saw would do a 27" tube with one filament approximately 15 inches away from the glass faceplate. I have no idea of the coating uniformity requirements for a TV tube but it all looked very shiny inside after blasting the one filament. I've also seen 24 inch mirrors done with the (one) filament offset half way and the mirror rotating to reduce the filament requirements. That is what I'll probably do in my chamber for the larger sizes and just try centering everyting for the smaller sizes... What have you tried? What works, what doesn't? How big is your Diff pump? I have 3 pumps, valves etc gathering dust. They are 6 inch size... Photo's are in the photo section I think. Ken Hunter --- In VacuumX@..., "James Lerch" <jlerch1@t...> wrote: Ok Ken, here's one for you.steel box out of 1/2" thick sheet steel. Ordered 15 feet of 10mm O-Ring cord touse as a door gasket and base-plate gasket.If I did the math correctly, we can use the system as followsbase plate and plumbing, by just lowering the box onto the baseplate, wherethe mirror will physically rest on supports in the door, and be coated while onedge.. (IE the box is tall and wide, but not very deep)pump the chamber down very fast, but we'll cross that bridge when we getthere :) thing I've found so far that I couldn't coat, was some painted wood (I know, bigsurprise! At the time I was trying to see if I could coat my secondaries withthe wood support still siliconed in place <g>)coating site) double bubble, toil and trouble.There just has to be someone doing something?! |
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Re: old parts anf stuff
What Size diffusion pump do you need / or how large is your chamber?
What kind of gauge do you need --thermocoulple / Ion etc
AGUSTIN GASPARINI wrote:
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Re: old parts anf stuff
--- RON WHITE <ron_white@...> wrote:
Mr Ron Withe: I reed your letter and I need parts as diffusion pumps, and gauges for vacuum. I wwillappreciate your help.Thanks you. ===== Alberto Gasparini Perito Moreno 1032 Godoy Cruz (5501) Mendoza ARGENTINA telefono 0261-422-0923 __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software |
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Re: Ho Hum again... stir the pot, add eye of newt, double bubble, toil and trouble.
James Lerch
Ok Ken, here's one for you.
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A few weeks ago myself and an associated welded up a 25*25*11" ID steel box out of 1/2" thick sheet steel. Ordered 15 feet of 10mm O-Ring cord to use as a door gasket and base-plate gasket. Were currently working on the door hinge and O-Ring seal system. Once that's done, were going to use an 18 point evaporator setup. If I did the math correctly, we can use the system as follows #1 12" diameter or less mirror only needs 6 of the 18 evap points #2 12 - 14" diameter mirror uses 12 of the 18 points #3 14 -24" gets all 18 points ;) Once the box and all the wiring is done, I plan on use my existing base plate and plumbing, by just lowering the box onto the baseplate, where the mirror will physically rest on supports in the door, and be coated while on edge.. (IE the box is tall and wide, but not very deep) I'm a little concerned my poor little HVAC pump won't be able to pump the chamber down very fast, but we'll cross that bridge when we get there :) BTW, I've successfully coated the following materials Glass (duh), Plastic, and Cured Silicone and Epoxies. The one thing I've found so far that I couldn't coat, was some painted wood (I know, big surprise! At the time I was trying to see if I could coat my secondaries with the wood support still siliconed in place <g>) Take Care, James Lerch (My telescope construction,testing, and coating site) "Anything that can happen, will happen" -Stephen Pollock from: "Particle Physics for Non-Physicists: A Tour of the Microcosmos" ----- Original Message -----
From: "Ken Hunter" <atm_ken_hunter@...> To: <VacuumX@...> Sent: Friday, August 15, 2003 17:40 Subject: [VacuumX] Ho Hum again... stir the pot, add eye of newt, double bubble, toil and trouble. There just has to be someone doing something?! |
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Re: old parts anf stuff
Don: I'll forward your request I don't want to give out his name without permission SVC wrote:
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Re: New Guy
Ken Hunter
--- In VacuumX@..., "jkeaser" <keaser.home@v...> wrote:
Hello all,Hi JK... Thanks for checking in. I am putting together a resistive coater (when I find a home) and will no doubt have a zillion questions to ask. Usually when we ask a question though the responder assumes we have unlimited budgets and PHD's. Myself, I'm just a guy that wants to vaporize some aluminum cheaply and get it deposited fairly uniformly on a large chunk of glass. Trying exotic materials or getting a super low vacuum is not my goal. Others here have different comments and goals of course. Any advise you can give us will be greatly appreciated. The group has shown a tendency to slow down at times and every once in a while I give it a nudge to get it moving again. Thanks again, Ken Hunter |
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Re: old parts anf stuff
Ron: I would be interested to know if the guy has any historical
publications or pictures that he would sell or lend to the Society of
Vacuum Coaters for publication on the HISTORICAL portion of our web
site.
Don Mattox
I just met a fascinating guy who owns a small vacuum research company which dates back to the 50s. If anyone needs parts for old equipment he has a junk room full of Diffusion pumps, gauges power supplies, E-beam setups etc. let me know what you need and I¨ªll pass it along. ? ? Yahoo! Groups Sponsor ADVERTISEMENT
-- ____________________________________
Donald M. Mattox Technical Director Society of Vacuum Coaters 71 Pinon Hill Place NE Albuquerque, NM? 87122-1914 Telephone 505/856-7188 FAX 505/856-6716 E-mail donmattox@... WebSite? http://www.svc.org |
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Re: old parts anf stuff
I just met a fascinating guy who owns a small vacuum research company which dates back to the 50s. If anyone needs parts for old equipment he has a junk room full of Diffusion pumps, gauges power supplies, E-beam setups etc. let me know what you need and Ill pass it along. ? ?
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New Guy
jkeaser
Hello all,
I have a NRC resistive coater that dates back around the early 60's. I have opened a part time business doing decorative coatings. I have been in the electrical feedthru business since 1989 and recently working for an E-Beam source manufacturer. I have 3 other chambers I plan to complete and go full time. If I can help anyone with coating equipment issues I will be glad to help. If I can't I know many people to ask. |
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Re: Ho Hummmmm
I would certainly suggest using multiple vacuum pumps. A "roots" type centrfugal pump will get you started and then maybe a liquid ring vacuum pump then your pump should do the job. The new refridgeration pumps will get to 50 micron. I am gathering all these things at tis time also.
Bill Lang, Stockton,CA |
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