Oscilloscope Camera Mount

13 09 2011

All photos.

Reader jsults turned my on to g3data… it’s a little open source program that helps extract data from graphs.

It looks like this in action:

I tried it with my oscilloscope photographs and it worked OK.  But it does not compensate for trapezoidal distortions.

If my camera were perfectly lined up with the oscilloscope g3data would work great.

This got me to thinking… maybe I could build a camera holder for the oscilloscope?

So I did.

I designed this mount using sketchup and had it printed at shapeways. It came in the mail today.


Works like a charm. Now all my oscilloscope photos will be perfectly centered and flat:

You can download at thingaverse or purchase at shapeways.


8 03 2011

I am very excited to learn of an effort to build an open source EBM 3D metal printer :


This technology is currently offered commercially by Arcam AB.

EBM fabrication is rather amazing. It can make fully melted metal parts from STL files.

I am planning to build the superconducting polywell in titanium using Arcam’s process. It would be amazing to eventually have a Makerbot for metal.

Additionally the EBM device itself has much in common with a fusion reactor. Both use high vacuum, electron beams, high voltage.

I’d be happy to help this project with any vacuum, high voltage questions.

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.


19 10 2010

Just got this sweet breadboard and jumper set. I really needed this!

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.

Chassis Cutaway

22 02 2009

I built this cutaway version of the chassis so we can do a fit and finish test with superconducting cable without spending a wad of money. 



20 02 2009

The parts from ProMetal just arrived. These parts feel heavy, dense, and strong. You really have to hold these in your hands to believe it. They hold water without leaking. Cost ~$30 each. img_3245img_3249

There is some texture, but overall these parts are highly conformal to the design. img_3264


This is very exciting. The first prototype core is within reach.

Next I will grind the touching surfaces of the lids and try to laser weld them together.


On the down side this material is magnetic:


I wonder if ProMetal can adjust the composition of the alloy. Stainless steel can be either magnetic or non magnetic depending on the alloy:

There are different types of stainless steels: when nickel is added, for instance, the austenite structure of iron is stabilized. This crystal structure makes such steels non-magnetic and less brittle at low temperatures.

Update: Looking at the ProMetal Materials Spec Sheet, it looks like they offer 316SS, which is non magnetic, although less strong than the 420SS. Bingo.

Chassis Fabrication

12 02 2009

I’ve found a vendor that can actually fabricate the chassis. ProMetal has a process that I would describe as the Zcorp process, but working directly with metal. They say they can fabricate the chassis and lids in a stainless steel / bronze alloy which has good physical strength.  Their max build envelope is 200 mm^3. This would allow for the fabrication of a dodecahedral core about the size of a basketball. The quote they gave me is within my budget. This is the only executable chassis option I have so far, so I am fixing my design on a radius of 100mm. I spoke with Prometal and they mentioned they have a larger format machine, but it’s down for maintenance  currently. 

I went ahead and ordered two of the lids from the copper coil version of the core. This will give me a feel for the process and material. I will attempt to laser weld the two lids together. lids


20 12 2008

Seeing as I’ll be doing a lot of prototyping, I figured it would be good to have my own rapid prototyper. So I’ve built a reprap, it’s almost finished. This is the ponoko model. Progress so far:  ponoko

Coil Winder

5 12 2008

Here are the pieces for the coil winder, partially assembled.coil_winder11


you can see the grain of the rapid prototype: 

Already I can tell the bobbin is not well supported axially. I doubt it will be able to keep tension with 12 gauge wire. But we can test thinner wire on this iteration. 

Putting it together:


As expected, the axel needed reinforcement:



Doing some quick checks. The stepper motors are supposed to take exactly 400 steps to complete a revolution. However, when I program the bobbin to take 400 steps forward then 400 steps backward, it appears to come just short of a full revolution! WTF! It looks like it’s closer to 415 steps per revolution. But I can’t trust that number to be accurate over many revolutions.

I’m learning RAD, a gem for controlling the arduino from ruby. Very cool.

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