Feb 21, 2010

Those six 1 1/2" square tubes have end plates that get welded on, and then have a threaded rod or a threaded hole in each one. The photo below shows how I cut the little squares that will be welded to the ends of the tubes.

When I cut the 3" squares out of 1/8" plate for the spiders, some of them were not exactly square, and were placed in a "reject" pile, so I cut some of these into four pieces using my chop saw. Since they were small, it was hard to figure out how to hold them. I ended up using the two C-Clamps, as shown in the photo.

Instead of using a threaded rod, I found some short 1/2" bolts with nuts, so I welded the bolts to six of the end pieces (squares), then drilled a 1/2" hole in six pieces, inserted a old bolt, attached the square, then the nuts, and welded them in place. The 100 Amp current from the welding machine messed up the threads a bit, so I ran a 1/2" NC (13) tap into the nuts to clean them up. The photo below shows the nuts and bolts attached to the end plates.

Also shown is a stack of freshly welded spiders that are in the process of being sandblasted. It was a nice warm day (80 F or 26 C) just ahead of another cold front, so I spent the rest of the day sandblasting and painting spiders. I got 11 done, and hanging on wires around the shop, before I retired for the evening news. Between the zinc fumes from welding the galvanized nuts/bolts, and the dust from sandblasting, I feel like I have been in a nasty dust storm! Plus all the sand in the hair and ears and shoes and...everywhere.

Feb 25, 2010

It snowed here and has been really cold for South Texas! I stayed in the basement and attached the mirrors to the painted spiders. 26 of them are now completed. I’m using Gorilla Glue that I bought at the local Wal*Mart store. It needs water to cure, so I sprinkled a bit of water on the back of the mirror, and dabbed some of the glue in the little square I outlined in pencil on the back-side of the mirror. See photo below.

The directions say to let the glue stand for a few minutes, as it takes about ten or twelve minutes for the reaction to begin. At that time, it expands 4X. Meanwhile, I take a rag and wet the piece of sandblasted steel that the mirror will be attached to, and then lay the metal spider carefully over the glue, and weigh it down with various hunks of steel. Watch it carefully, because when the glue expands, it often moves the spider around on the back of the mirror. The excess oozes out around the edge of the steel, and eventually you learn not to put too much glue on the glass. The amount shown in the photo on the left seems to work for me. If it does slide around, you just shove it back into position. In fact, in the photo above, on the right side, you can see that the spider needs to be slid up a bit. (That happened while I was taking the photo!) So far, all of the finished assemblies are correct, but the process needs watching. It is easy for a sleeve of the jacket to brush the spider when you reach up to switch off the light.

March 5, 2010

I’ve been working on the frame that holds the mirrors. Both ends were fastened to the six bars, and they were mounted into the frame, and once everything was tested to make sure it turned freely, the frame was fastened securely together. Unfortunately, one corner got screwed up, and needs to be re-done.

The boat trailer now has the tail lights and poles (for holding the boat in place) removed. This afternoon, the location for the square tubing was determined, so perhaps by next week, the frame holding the array will be mounted on the trailer. At the hitch end of the trailer, a two-wheeled cart has had a 1 7/8" ball attached above the axle, and this will allow the trailer/with concentrator to be pulled into the barn during storms. It will also allow the concentrator to be easily rotated to follow the sun.

March 9, 2010

The bracket that is going to hold the two square tubes that the array will sit on has been finished and even painted. I welded two pieces of angle together that fit around the tube, and then welded four threaded rods to the sides of the angles (that now form a U). There is a good weld, but the whole weight of the array will be "teeter-tottered" across the rear of the trailer, and if the weld should break, the array would fall to the ground. Hence the large clamp. (Now I’m worried that the two 1 1/2" 1/8" walled square tubing might bend!) Here is a photo of the bracket or clamp.

I also managed to sandblast and paint five more spiders today. Over 80 degrees F is good painting weather!

As soon as the frame for the array is mounted on the trailer, a photograph will be inserted here. Well, the photo didn’t come out very good, so I will replace it as soon as I pull the whole thing out into the yard, but first I need to do some more welding (pulley system for moving the mirrors). March 12, 2010