High vacuum chamber
Task list
Research which vacuum device supplier catalogs are best information wise! ( we need to help each other up the learning curve)
Design build & test conventional manufacturing and Self print manufacturing route ;
CF flange - to be welded on stainless plate, Consisting of two parts plus copper ring seal a) Short pipe and flange, b)an end CF flange fitting ( holding ; windows or electrical connectors or pipes to pumps or electron gun or etc...)
*** TOP Priority ( as expensive to buy so need to design and a challenge to self manufacture)
Vacuum chamber rotational motion feed-through See here[http://www.lesker.com/newweb/sample_manipulation/rotarydrives_magidrive_md25.cfm?pgid=0 ] - *** TOP Priority
air filter subµ- to protect roughing pump and turbo pump from metal powder
pipe fittings to pumps & gauges
valve to close electron guns from main chamber inner diameter min 12mm
low voltage electrical connectors
leaded window Min diameter 12cm ( should be equivalent X ray shielding to 2mm lead or 6mm stainless, but could bodge with stainless shutter if too expensive.)
door locks ( Door will be whole front side of chamber, ie H 1.6m x W 1m)
*** TOP Priority
Viton O ring Main door seal or alternatives
Solnoid casings to avoid the need for tefelon coated wire.
Later
Cleanup external Arm glove Inner door Port hole- So for 1µ size active metals (aluminium , Titanium ) - after print flood chamber with nitrogen and Sandblast/hoover parts inside chamber via arm gloves ( to avoid exothermic reactions as the nuclear industry refer to them.).
Vacuum airlock so print while repump
pumps initially purchase
guages purchase
General Advice
All parts should be made of low outgassing materials see here [1] Stick to this list / or materials with values like these and you won't go far wrong.
Weldling; avoid dirt accumulation nooks and crannies, weld from inside full depth ( i.e. not both sides leading to trapped internal air pocket).
For sub 15µ powder use optional atmospheric pressure (1 Bar) arm glove entry lockable port holes, for sand blast & suction/vacuum cleaner clean up (using metal powder not sand in blaster & Vacuum cleaner) Sieve metal back to metal powder hopper from vacuum cleaner and needs compressed air supply here.
Special case of active metals i.e.Titanium, Nitrogen reduced oxygenated cleanup See nitrogen separation tube here[2] also needs compressed air supply.
Use airlock for build while pump down contained in vacuum chamber door,
Further reading ; Vacuum chamber principles; Essential reading before you weld/construct your vacuum chamber, Basic Vacuum technology by Varian
