3D Printed Bronze

9 11 2011

All photos.

Years ago I looked into Prometal’s 3D metal printing process. The results were impressive but the stainless steel is magnetic:

This disqualified them as magnet holders!

Recently Prometal let me know about an experimental bronze process they are developing. Bronze is totally non-magnetic. BINGO!

Prometal donated a test part to see if I could make an airtight braze with a TIG welder:

The part was to be brazed to a Swagelok VCR fitting like this:

Prometal is still adjusting the process. This test part is a bit oversize so it was difficult to braze, but we got something:

The bronze attaches to the stainless nicely.

I was excited to put it in the chamber like this:

But I screwed up. I welded on the wrong VCR cajon. This one is two short to catch the male thread once the gasket is added.

Dammit.

I had the right part here all along; shown on the left:

So no vaccum check for now. But it looks like the 3D printed bronze parts braze nicely.

I count that as a win. Think of the parts I can make with 3D printed bronze + brazing.





Welding 3D Printed Steel

16 09 2011

All photos.

My shopmate had a TIG welder here the other day.

I took the opportunity to try welding the 3D printed metal parts I made last year:

These are intended to be coil holders, so I installed a 40 turn coil prior to welding.

Mike welding the halves together:

We used no filler rod on the theory that the infused bronze would melt and form a braze of sorts.

It worked very well:

The coil insulation didn’t survive: The coil is conductive to the casing.

I’m encouraged by the weldability. I am ordering more test parts to keep pushing this approach.





New Materials for Electron Beam Melting

26 07 2011

Previously I looked into Arcam’s 3D Metal process. At the time, Arcam’s Ti6Al4V Titanium Alloy seemed the best option.

Today I checked back to Arcam’s materials page and it’s been expanded to include:

I’m happy to see stainless steel and amorphous metals (although the stainless 17-4 is magnetic).

Soon I will be ordering calibration parts using a variety of 3D printing technologies and materials.

UPDATE: Also check out this amazing polishing technology: Electron Beam Machining. This might be perfect for polishing 3D printed  metal pieces.




Glazed Ceramic 3D Printing

7 07 2011

This BoingBoing post illustrates the latest in glazed ceramic 3D printing.

I purchased this coffee cup:

I bought it because it’s cool, and to test the electrical and outgassing properties of the printed ceramic.

It may be possible to build custom ceramics for the magrid/standoffs with this process.

If I can braze this ceramic to metal… we can build almost anything.

Here are the design rules for this printing process.





Bellows Holder

19 12 2010

All photos.

Back in the lab today after some travel out west.

Previously I designed a bellows holder to keep the high voltage feedthrough from moving.

I received the part and installed it successfully today:

A real win using 3D metal printing.





Coil Formers

12 02 2010

My shop-mate Stuart machined these coil formers from a teflon rod:

Here is a time lapse video of Stuart machining the  formers on the lathe:

Next we have to drill four holes in each former and connected them with angle brackets.





New Inner Grid

27 10 2009

Yesterday I made a new fusor grid:

IMG_4406

With an 45mm OD, this grid is smaller (and prettier) than the previous at 65mm. The old and the new grid side by side:

IMG_4413

 

Read the rest of this entry »





Arcam EBM fabrication

19 10 2009

I’m exploring the Arcam EBM process for fabricating the magrid.

Our current scale is within their build envelope (250 x 250 x 400 mm and 350 x 350 x 250 mm).

Their process creates a fully solid / fully melted part using Ti6Al4V Titanium Alloy.

Titanium is non magnetic (paramagnetic). GOOD

Titanium has low outgassing (I _assume_). Not seeing good information on this, but I see articles about low outgassing. GOOD

The fully melted part should be vacuum tight. GOOD

Titanium can be welded, but it’s complicated. Gas shielding is required. WORKABLE

Titanium is difficult to machine. It requires specialized tools. It’s tough and springy. Too hot and it reacts chemically. The magrid part is likely too delicate to be secured for machining. We can still lap sand the faces for better mating. BAD/WORKABLE.

Titanium is strong. GOOD

Titanium is beautiful. GOOD

The part would be highly conformal. I do not expect the warping as with the prometal magrid. GOOD

Price. This same part would cost around $2500. Better get it right the first time. WORKABLE

Although it’s a path fraught with peril, it could lead to a fully functional superconducting magrid.





Day One

3 06 2009

What a day.

First off, we have achieved FIRST VACUUM. Connected the small chamber to the pump. So far I’ve got it down to 3e-7 torr and dropping steadily, which gives us a green light for the Fusor:

small_chamber_setup

We had an initial false start which was caused by poor connection on the last conflat to be connected. The last flange is always the hardest because there is more weight on the system. The setup is pretty precarious, and only serves to check first vacuum.

Secondly, Deez successfully fabricated the fusor core:fusor_core

Here is a time-lapse of day one:





Grid Fab

2 05 2009

Took a stab at fabricating the grid today. We used Oxyacetylene torch to braze the welding wire together.

ox_acet

I managed to make the rings:rings

Tried putting it together, but I kept breaking previously brazed joints. I think I need to attach heat sinks. grid_attempt








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