shipping and manhandling

As I stated in my very first post, the intent of this blog is to primarily write about my experiments with electron vacuum physics. In order to do that, I need equipment capable of pulling a high vacuum - somewhere in the range of 1 × 10^-5 to 1 × 10^-6 Torr. Unfortunately, achieving this level of vacuum requires careful chamber design, material selection, and somewhat fancy equipment. Luckily for the budget-minded experimenters, eBay comes to the rescue. There are plenty of resellers of used research and industrial equipment, so it never ceases to amaze me the types of things you can find. Sometimes it's stuff I never even knew existed. Often for a tiny fraction of what it must have cost when new.

I've been keeping my eye out for equipment necessary to build a vacuum chamber, trying to get a rough estimate of what it would cost, and of course, any obviously good deals. You can find out more about what it takes to build such a setup by checking out Ben Krasnow's blog (specifically related to his incredible DIY scanning electron microscope) and Sam Zeloof's homemade ICs. As luck would seemingly have it, I found the following:

 An early R2D2 prototype, best I can tell

First off, sorry to anyone reading this who I may have outbid. I was pretty set on winning that auction, and win that auction I did. From the description, it wasn't entirely clear what it originally was for. Best I could tell, it was for degassing mass spectrometer filaments, but I couldn't really find similar examples online. Anyone out there reading this know? Leave a comment! The listing didn't say much other than it was a vacuum chamber and that it had a Pfeiffer TPU-110 turbomolecular pump. After gleaning through the available not-so-high res images, I determined it was basically a backing pump and a turbopump power supply/controller away from being a complete setup. The lowermost rack unit was the controller for the hot cathode ionization vacuum gauge, with the actual sensor visible in other images. The middle rack was obviously some sort of timer, and the top rack was a triple filament power supply for the 3 banks of filament sockets

There were some other random bits in there that I was able to verify after receiving it, such as an electromechanical valve, a thermocouple-type vacuum sensor, and some other process/safety-control related bits. 

I ended up winning the auction for $260! If the pump was in operating condition as claimed in the listing, that's a hell of a bargain. I was planning on taking a trip midway across the country in a rental van to pick it up, just to realize the seller specified no local pickups. That sucked. I would have felt much better knowing preparation and transport was in my own hands. As it turned out, my concerns weren't unwarranted. 

After the seller quoted me almost $500 to mount it on a pallet and ship it via freight, all I had left to do was to pay up and wait for it to arrive. It came in a week later, and basically the first thing the truck driver told me was that I need to look it over and decide if I want to accept it because it was damaged in transit. Ugh. We hopped in the back of the truck, and the first thing I noticed is that it most definitely wasn't on a pallet. Nope. This top heavy piece of equipment of nearly 400 pounds was shipped on it's own casters wrapped in a few layers of plastic film. I expected better from a seller with over 80k sales. Even without removing all the plastic, it was obvious that it probably did a few faceplants during loading and unloading in transit. 

I had to make a decision. Accept or refuse. Since I wasn't planning on using it for the same functions it was designed for, I didn't care about all the included equipment. My main concern was the condition of the chamber and the pump. The components of the chamber are pretty stout, and the damage looked minimal and serviceable. The pump itself was impossible to gauge. Did the bearings survive? Well, the ion-type sensor which is in a glass envelope did, so just maybe, or hopefully, the pump did too. Maybe you're wondering why I would even consider keeping it when I could just get a refund and start over. Truth is, it's very difficult to find and equivalent setup for such a price, and so I weighed the risk, and took my chances. Here is how it looked after unwrapping:

Not even good from far, and definitely far from good.

Some of the screws that held in the racks must have gotten stripped and popped right out. Each unit had damage. I'll detail the extent of those in a later post. For now, I'll give you more schadenfreude ammunition.