hi Thaddeus W For your welding shading problem at mains frequency due to filament modulation. Have you thought about a rectifier on the high voltage side of filament transformer, so you go DCacross the filament, easier than going 400Hz? kind regards Rapatanby rapatan - MetalicaRap
hi Interesting I will have another look at that ike system, no hurry on the diagrams in your own timing! Just a little addition to pump discussion; Ion pumps are limited to 20 hrs of use at 10-3 Torr and 400,000 hrs at 10-8 Torr before titanium plate maintainence , but this is not the case with hot filament titanium sublimation pumps, the question is will the beam melting liberate the rightby rapatan - MetalicaRap
Hi Thaddeus W I would be interested in the transformer control option diagram you offered, you could send it here or to my private message account here. Have you seen this control option, which a lot of the MRI guys are also using , but needs a 100KV tetrode/triode valve control ( not found a cheap one yet!). search in google on exactly ie with quotes "current control in an electron beam welderby rapatan - MetalicaRap
hi The major price block untill ours is ready is the high voltage power supply, so getting hold of an old xray power supply is probably the best bet using it for short 10S runs. Right now I would focus on vacuum test chambers with roughing pump and pirani guage. See what sort of electrical feed throughs and mechanical feedthrough you can achieve. what sort of welding or glueing techniques work aby rapatan - MetalicaRap
hi could you check the tube number again? E130L? see other posts in vac section kind regards Rapatanby rapatan - MetalicaRap
Hi Thaddeus W Could you double check the vac tube number again as the E130 L tube you mentioned above has a peak maximum voltage is 8KV. E130L Vacuum Tube data sheet link click They are running around100KV ? What configuration are they using the tube/tubes in? what other components? great if you could help kind regards Rapatanby rapatan - MetalicaRap
Hi Avoid brass it can arc badly, copper is good. ( link in vacuum section to home build electical feed throughs done by fusor bunch) Oil diffusion pumps introduce oil that can crack on gun filament so , turbo pumps are for the rich though and the bearings do play up. Vacuum wise things can be a lot more rough and ready than you would think(home build large spot electron gun), as long as you notby rapatan - MetalicaRap
hi Getting the power supply under the 1000 euro level is applying 5 year old smps technology to home kit building, so adaption and testing The beam current control is 30 yr old technology which we are replicating. The electron gun triode is very old tech we are replicating The powder dispensing side in argon at low vacuum is prior knowledge, but powder dispensing in high vacuum (10-4 Torr) will rby rapatan - MetalicaRap
Thanks Thaddeus W for your great input! Your transformer beam control option looks interesting, if you had time to specify some parts we would really appretiate it, as our valvue option is proving complex and time consuming! kind regards MetalicaRap team you can send it too me in private if necessary via forum user name Rapatanby rapatan - MetalicaRap
Hi Its current 1m beam tube lenght is necessay so it can cover the whole 30cm build area while being within the divergence angles in existing inter lens deflection electron beam welding guns, so MetalicaRap remains compatable with existing commercial gun technology , and so people have the choice to follow that route if desired. Electron beam welders beam deflection was only inteneded for minor aby rapatan - MetalicaRap
hi For the non window design yes it is the same 30cm^3. For the high tech window design the build platform is up to the size of your "argon tent at atmospheric pressure" and the time your willing to wait. kind regards MetalicaRap teamby rapatan - MetalicaRap
hi thanks for the kind words you can now donate directly via the MetalicaRap paypal account; MetalicaRap@3iii.dk kind regards MetalicaRap team P.S. You get free printing time if you contribute enough!by rapatan - MetalicaRap
hi Now got vacuum chamber materials down to 2400 euro plus weld and fittings, via 2 lengths of 304 sch2014inch pipe with an aluminum hopper box cut out from one thick sheet with a 304 plate acting as bottom of the box. Any other clever solutions? out there? kind regards rapatan and metalicarap teamby rapatan - MetalicaRap
hi Interesting We can use the beam to melt the metal, Need room to cast does that require special air systems etc? kind regards Rapatan metalicarap teamby rapatan - MetalicaRap
Great! thanks for the info MetalicaRap teamby rapatan - MetalicaRap
Great ! Power vacuum valve electrode do not traditionally have replaceable filaments, ( ebm filament e.g Tungsten ribbon 2mm wide 0.25mm thick.) normally an EBM tungsten filament lasts 7 to 100 hrs, but if you could see a way to allow replacement or find a cheap power vacuum valve electrode in tungsten with an exposed filament area of about 3mm2, at 2500 C that would be great!! kind regardsby rapatan - MetalicaRap
hi Yeah vacuum technology is a new learning curve for most , UHV chambers go down to 10-11 torr, these chambers are tricky, we nee to get to 10-4 Torr this is much less demanding on skills of welding and machining, you can even use glue sealants for leaks on these 10-4 chambers. For the bootstrap prototype using the old fashioned tried and tested simple TIG welded H 0.8m x W0.8m x Depth 0.4mby rapatan - MetalicaRap
Interesting method for N2 , If you feel like pricing out the different methods that would be great! kind regards MetalicaRap teamby rapatan - MetalicaRap
hi The above link to the subsection did not work You can find it in the usefull links section of metalicarap site ( near the bottom) Its called "Discussion of Advantages and Disadvantages of different Tool head processes" good luck Oh We had bad news today we had an electron microscope donated to us from a university for vision system development they said they would keep it for us, but whenby rapatan - MetalicaRap
Hi As you said, "it will be difficult to make fine work" this is critical as you may need all the other machines as well, If you want to look at nasa's metalurgy lecture on metal forming in a vacuum you will see its advantages; # see this video podcast have a look at the following section; . You might want to add a TIG section with your ideas. the sub section below gives some guidance oby rapatan - MetalicaRap
its not a kickstarter type project they say, they don't like that it may reproduce its self. MetalicaRapby rapatan - MetalicaRap
project page link as requested kind regards MetalicaRap teamby rapatan - MetalicaRap
Our application is in! thanks MetalicaRap teamby rapatan - MetalicaRap
great its done kind regards MetalicaRap teamby rapatan - MetalicaRap
hi I have been told that EOS 3D printer uses nitrogen it makes itself within a few minuets, Would be great to know how to create the Nitrogen. great work Kind regards MetalicaRap Team / Rapatanby rapatan - MetalicaRap
thanks kind regards MetalicaRap teamby rapatan - MetalicaRap
Hi Good to hear from you, In MetalicaRaps case to keep a defined beam for more than 2cm you need high vacuum achieved with 2 pumps; roughing pump and turbo pump (/ or oil diffusion pump) See below. Turbo pump for High Vacuum 10 -4 Torr only works after using a roughing pump ( see below), Leybold TW 400-300-25 or Leybold 700 700 litre/S Vane pump roughing pump Varian DS102 you can get thby rapatan - MetalicaRap
hi Please mail me here you can do it privately to user Rapatan at labitat.dk I will send you our metalicaRap Bank account details, and transfers details thanks for all your support kind regards Rapatanby rapatan - MetalicaRap
hi Fascinating idea, maybe you would like to add it to future development section of MetalicaRap? kind regards rapatanby rapatan - MetalicaRap
hi Excellent that would be great ; Can I suggest you choose which part of the electron gun you would like to research? from: Rf input, Rf Ariel,cathode, anode, Lens coil, alignment coils, nozzles, L. alignment coils, nozzles (aperture ) , deflection coils. see schematic shows position of the above Calculate for 6kw 150KV unipolar or bipolar cathode to anode connection. Note: special awarby rapatan - MetalicaRap