Students in BME 206 designed, drew, and then fabricated this set of low cost, small wire tensile tester grips. Its functions very well. It compromises correctly on being a little more difficult to load but is fabricated out of one piece of rod stock (plus a roll pin, screw, and washer). Students when shown the $700 commercial solution as an example, and with repeated prompting from me "simplify" did genuinely do the design. The students then machined the entire pair taking turns under supervision, on both the lathe and mill. 

Working with Andrea, a grad student in the Calve lab at BME, over several interactive design sessions we built this. The original requirement was "Place a force equivalent of 1-4 grams onto embryonic collagen and image it in a fluorescence microscope to provide a three dimensional image of its response to the force over time (It should organize and we'd like to see how that order originates) Things naturally started complex, stepper motors, flexures, force sensors for feedback etc. 

We ended up with a ebay bought, $30 record player tone arm. It has a built in 1-4 gram adjustable weight in the back originally to set the needle tracking force. A teflon pad in the front is at a slight angle to apply the force normal to the optical plane of the scope. Seems like cheating. 

A lab I support in Aero Astro needed a way to drop a single drop of oxidizer onto a test watch glass with drop of fuel in it. They record the reaction with a high speed camera. The challenge here is that the oxidizer is; corrosive, toxic, explosive and boils at room temperature. Working with the Purdue chemistry glass blower (Thank you Bob Gorman) this device was designed and made. The teflon rod in the center releases a single drop of the condensed liquid from the very bottom by turning the knob at the top, the whole device is water jacketed for cooling and safety. The apparatus was successful on its first deployment and has allowed the lab to take data previously unavailable. Its compact combination of continuous addition funnel and condenser.

Some UHV tricks

Electro polish everything small enough
 to get into a 1000ml beaker

Per MDC: add a auxiliary valve to a gate valve to
 allow venting a small subsection of the chamber.

Per Yeats: Add a keg or other vessel behind the turbo
 to allow extended running w/o the foreline pump. 

Scrounge variac boxes from discarded
fume hood. Re-wire as bakeout consoles.

This is a small submersible e-chem cell that uses a Keck Clamp for the sealing force.
Parts are Teflon  Viton, and an IDEX micro-fluidics fitting. This was designed with extra material and the ability to turn one face to make a snug sealed fit. It can be adapted to measure on the face of the surface exposed to the fluid, or the back in the case of conducting substrates. We may make a new version of this with the IDEX fitting inserted in the side.

Berth for the Flagship

STM A was given a new home at CNSI during the move. This is the Acoustical chamber which was assembled on site from parts pre-fabricated to prints. The chamber fit in the room exactly as spec'ed, the optical table fit in the chamber as spec'ed and the instrument fit on the optical table as spec'ed. Tolerances for fits were a little as 1 inch in the space where the dewar and support equipment is lowered into the pit underneath the table by the overhead crane.

New claw for vertical sample transfer in UHV

STM B, the lab's second UHV STM, had a very troublesome method for sample transfer  It used an outside grasping claw that had no positive contact. Thus it was possible to drop the sample. This compound claw grabs an ID ring thus once engaged, cannot fall off. Additionally it uses shoulder screws in compound shear and simple strong parts throughout. Hopefully grad students will take a while to break it and be able to fix it easily when they do. All Stainless steel save for the little thrust washers which are wire EDM'ed 945 bronze .005 thick. Design was super simple, easy to machine and modify. All parts were electro-polished.  

very precise parts in stainless for SNAP

The print for these was very intimidating. In the end the shop ground and wired them to size, so I was making them +.002 in most dimensions. They are used for aligning gluing fixtures for the CCDs in the SNAP telescope.

Very tiny copper parts both different.

These are mirror image parts and hold a small door on a detector. The Copper is OHFC for vacuum. The largest dimension is the length at 11.5mm, and the smallest is the meeting vent holes at 0.4mm. The wide machine put the slot in with .006" wire. They darkened slightly because I has them on aluminum overnight; that was electropolished off in the cleaning for UHV vacuum.

Clamp bodies for SNAP

Two were made. Work on 4 sides and substantial material removal. The bottom of each of the large holes in the side has a 8-32 thread that required a pulley tap to get to.

intricate stainless steel part

This was a production prototype for testing assembly and welding of a cooling manifold. Small copper tubes are brazed into the back of this and feed coolant several meters into an instrument.
It has features on all sides. It was surprisingly light -- the designer wanted as much mass removed from it as possible. Controlling the bend after material was removed was an issue.

Bridgeport over and under

One amazing property of the Bridgeport mill is its extreme flexibility.
These two pictures showcase an application where a large aluminum ring needed tapped holes on the exterior and interior edges. A very precise setup was made that located the holes for both surfaces using gage pins, 123 blocks, heavy parallels, and an angle plate. The setup is showcased on the "outside setup" and the whole scene in shown on the inside setup.

small instrument rebuild

Various parts of the device were reworked for greater stiffness.
The small clamp was also designed and machined new. The XYZ linear stages were rearranged for better clearance and user operating comfort.

Making a table saw accurate

The table saw is handy for dealing with large stock in acrylic, Delrin and aluminum.
Should you need to saw to a finished length you can get reasonable accuracy with a setup similar to this, provided the gate is stiff enough.

Latest large project

A quick photo of what I have been working recently. Lots of 80-20 channel strut. This is very nice stuff to work with. I found a way to chuck it up in the engine lathe, this allows the ends to be finished to precise lengths and for the end hole to be 5-16-18 tapped easily. More details on this in the near future as its a work in progress and many parts are yet to come.