Thursday, March 14, 2013

Hamburgers and Telescopes Part 2

We discovered a great little lunch spot right down the street from where we installed the Aqawan at Caltech. My first vacation lunch there consisted of a tuna melt with homemade macaroni salad, lemonade, a strawberry milkshake, and a piece of banana meringue pie. I have never seen banana meringue pie anywhere before. Needless to say I was stuffed and useless the rest of the day. But hey, I was on vacation anyway.
 I getting hungry again looking at this picture. The installation of the roof panels went off without a hitch. There were quite a few mechanical details to take care of before we could actuate the roof clamshells.
In this picture you can see the roof opening and closing mechanism better. A common shaft is driven by two separate gear motors into a chain directly connected to the roof sections at each end. The black tubes house a steel counterweight that keeps the slack side of the chain tensioned. The gearmotors are 24V DC with 100:1 gear reducers. You can also see the vee groove track wheels that run on an inverted angle welded to the top of the frame in this shot.
A closer shot of the chain connection to the roof clamshell. The chain is driven by a sprocket keyed to the shaft. The upper and lower sprockets are just chain guides.
This is one of my favorite things. Since we didn't have the electrical control panel yet we had to operate the gearmotors someohow. Don is always thinking and came up with this field expedient tool to open and close the roof. You don't get too many actuations off a battery charge but you can open and close them.
We added sheetmetal to the ends and painted the whole thing. The painting was the worst part. The reflection in the hot sun combined with two coats of bright white paint made for some blinded painters. I managed to not get any paint on my shirt until the very last panel.

After all the hard work there was a little time to snoop around the Caltech campus. I'm telling you these kids have a great place to go to school. Just the architecture is impressive. All the lighting fixtures and door hardware are top of the line hand made artisan stuff. The walls between the stalls in the one restroom we were using were solid marble panels.
Looking toward the Millikan pond.
This beast caught my eye. Rock Island Arsenal  Model 1890 on a 1900 mount.
Underneath was a cool differential square thread elevation adjuster.
 A sample of some of the building facades. This is the building with the coelostat on the roof. 
As we were walking around I noticed an open door to one of the machine shops. When we got back to the Aqawan I spoke to the project manager and asked If he might make an introduction for me to get a short tour. He was more than happy to help out. Apparently there are quite a few machine shops on campus so there was some confusion as to which one to go see. I told him whichever was the largest one.
It turns out the largest machine shop on campus is in the basement of the physics building. Stay tuned for an article on my adventure in the basement.

Thanks for looking.

1 comment:

  1. Was the mount for the 3 sprockets a custom job or was it an off the shelf component? Looking for something similar myself.

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