MetalicaRap Future Developments

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Live build part heuristic simulation Rather than just remove blob errors on every 10th layer, develop a live model of the build progress of the part and update shape with 3D map of error blobs from scanning electron microscope, then modify following layer G code to take in to account existing blobs during the next layer metal addition , and thereby only intervene subtractively when blobs effects outside of the part.

MetlaicaRapWin

Optional beam windows; High tech stationary window or Low tech scanning Aluminum foil slot shaped beam window.

• As the window version will run at 10-7 Torr LaB6 filament is possible (expensive but 1000 hour filament life and 40 times brighter),

• One Self printed Electron beam titanium sublimation pump Or distributed Ion pump with some tantalum, slotted cathode cells for argon gas collection[1] or oil diffusion pump or turbo pump. (prototype uses turbo pump)

• Second pump is a self printed High vacuum Titanium sputter-Ion pump (with some tantalum, slotted cathode cells for argon gas collection [2]) or our invention Electron beam titanium sublimation pump. Prototype before self print, bought in oil diffusion pump (messy with expensive oil 100euro/litre) or turbo vane pump(4K euro extra) .

• Second pump types sputter ion pump or oil diffusion pump will need to be closed off from the chamber during chamber access and roughing pump cycle, to save cost avoiding large gate valves reduced pumping rates will be accepted through the use of smaller radius gate or ball valves with smaller 4 inch or below type pumps . ( later self print gate valves will be investigated)(An oil diffusion pump can not pump at atmospheric pressures and can ruin the oil trying to do so).

• (For ion pump; Use electron guns focus coils to provide magnetic field to sputter ion pump [3] 50L/s max, short duration between maintenance 30Hours , self cathode refreshment by electron beam surface melting exposure in MetalicaRap's beam)

Our high vacuum pump will be a sputter ion pump as has a cost reduction and ease of use advantage for us especially with the window option . As the high vacuum turbo pump cost has been a block to costs coming down, but after redesign an Ion pump seems a good solution, approximately 300 tubes (anodes at 8KV) 15mm diameter 26mm long made of stainless, with 8mm diameter titanium plates ( cathodes at 0V) fitting in either end of anode tubes , leaving a 3.5mm gap for the gas to enter, these are situated around the outside of the lens coils providing magnetic fields in their own stanless steel cans and a 8KV supply hooked up, we have create a electron gun and ion pump combination pump. The number of tubes control the pumping rate it lasts 400 hrs at 1 x <math>10^-</math> <math>^4</math>torr but 40000 hrs at 1 x <math>10^-</math> <math>^6</math>torr . slotted cathode cells for argon gas collection [4]

14 inch pipe (NPS 14 min. SCH 20 ) with one 100mm thick Aluminum plate with interior "carved out" for hopper box sides and top, a further 304 plate for bottom of hopper box with o-ring seal, 304L Top and bottom pipe end caps if not domed min. 18mm thickness typical 25mm thick with copper CF flange and hinged window access.

The refill hopper will be situated in the side of the 14 inch OD diameter gun tube and will obscure a little part of the build chamber from the beam(a necessary compromise). (Technical background: See 5.2 [5]see lecture 4.02/11/04[6],[7]

• Viewing window/ Door 8inch borrsilicate glass, 3/8 thick, standard 10 inch CF plate and Oring.

Possible

Solar cell production demands conductive transparent top surface layers Indium tin oxides traditionally uses electron beam physical vapor deposition EBPVD [8]. Gun details required.

Polishing Plasma through the addition of argon and a defocused beam, polishing out roughness from a typical powder printed finish Rq of 25 nm to a polished surface Rq of 4 nm is possible , there are other low tech polishing methods that may be easier eg. Tumble finishing. EBeam Polishing [9]

Ion Pump to remove waste vaporized metal.

Focused ion beam / Ion beam etching gun to take dimensions to sub µ level(1µ over 20mmIT0)(Future development issues, SEM measuring absolute distances over a 300mm depth of field in FIB mode .)