What Ever Happened To The Big Bertha Rebuild?

What Ever Happened To The Big Bertha Rebuild?

This state senate campaign has just gobbled up way too much time (as you might expect), so something had to give--and what gave was Big Bertha 2.0. But I did receive the 4" wide aluminum channel, and after a bit of examination, I concluded that there really wasn't a need to epoxy the 1/8" thick piece of aluminum into the channel.

Here you can see the channel bolted to the tube rings:


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Of course, none of the existing 1/4"-20 bolts were the right length (some too long, some too short).

Here you can see the top side of the channel, where the bolts holding the dovetail plate go:


Click to enlarge

And here's the saddle plate side:


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There are a total of four 1/4"-20 bolts attaching the saddle plate to the channel, and since two should have been theoretically more than enough, four is way more than enough.

However: my wife is anxious to get the enormously huge Big Bertha 1.0 tube assembly out of the garage, so we went ahead and tried to put Big Bertha 2.0 on the Celestron CI-700 mount this afternoon. It turns out that:

1. I don't have enough counterweights to balance Big Bertha 2.0. I have two 23 pound counterweights that came with the CI-700, as well as an 11 pound, and an 8 pound weight that came with the Losmandy GM-8. It's close, with all 65 pounds at the end of the counterweight shaft, but not quite. So I need to buy some more counterweights. Probably one of the Losmandy 23 pounders should do the job, allowing the 11 and 8 pound weights to go back to the GM-8.

2. Remember that I knocked the CI-700 over a few weeks back, breaking one of the parts, which I then had to get welded? It turns out that the welds didn't survive the load of the counterweights on one end of the shaft, and Big Bertha 2.0 on the other end--and the parts that broke off the end, broke off again.

I had noticed when I got the part out last time that it was almost something that I could machine myself, if I needed to do so. It might not be as elegant as the original, but it would be close. I guess that I need to do so. I'm sure that if I machined this part from a solid piece of aluminum, it would be strong enough to handle the load. I confess that I am tempted to machine it out of a piece of steel, however, just to make sure. If I could find the part for sale, I would buy it.

Today being the Sabbath, I think I'm going to concentrate on relaxing instead.