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Tuesday, April 13, 2021

Weighted Belts?

I need a way to add 3-5 pounds to one end of a 10 OD telescope tube.  My smaller 8" reflector has some advantages over the 17 5" but when doing astrophotography with eyepiece projection the extra weight at the eyepiece end needs a few pounds at the bottom of the tube to keep balance.  The ideal would be a Velcro or elastic band carrying several pounds of weight.  Leg weights would be ideal but how many people need them for a 32" circumference ankle?

10 comments:

  1. Nylon webbing for the length, velcro to fasten it. Another idea, nylon webbing and velcro with an ammo pouch on it. Then you could add and subtract weight to get the balance you want.

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  2. Nylon webbing belt, 1.5" up to the 'tactical' 2 1/4". Leg weights in those little mini-sandbags. Needle and thread, you're done.

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  3. Amazon has a variety of cut-to-length belts in different widths, and you can chose between elastic and non-elastic.

    Thinner webbing and grosgrain sew easily on a home sewing machine.

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  4. Glue one side of velcro to the tube.

    Glue the other side to scuba diving weight(s).

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  5. Probably not applicable to your particular telescope and its mount, but when I built my ten inch dobsonian under John Dobson's tutelage, I added the ability to move the tube fore and aft in the mount with a knob to lock it into place. So balancing it with different eyepieces, cameras, finders, etc. is trivial. I can send you a picture of how it was done if that is of interest. All was done with common tools.

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  6. Weight belts for scuba divers.

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  7. Lots of good suggestions. Jim: There is a way to move the telescope fore and aft, but loosening the clamps that hold the dovetail means controlling movement by myself in the dark. I was adjusting balance the other day and I did not get it quite tight enough. Fortunately it only fell a few inches very slowly and landed on something soft (my foot).

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  8. A thought. Don't those building cranes have some sort of moveable counterweight?
    Perhaps a rod in parallel with the tube axis, attached to the tube and you could slide the weight fore and aft as needed.

    The automatic system would contain sensors and a small pump to detect off balance and move mercury from tank to tank.
    Yes, I borrowed that idea for submarines, and I'm sure the mercury would make it a no-go for today.
    It would be neat.

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    Replies
    1. Larger commercial telescopes used to have something like that. Thanks for jogging my memory.

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