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Aiming my dob

  1. Mar 4, 2010 #1
    ..sucks. I have the Sky-Watcher 10" dob (got it for xmas). All around, it's a great scope for the cost, and produces some very crisp visuals of surprisingly distant objects... when it can center on them. I find myself having to constantly aim higher than the object so my telescope will "fall" onto it and hopefully stay. It's getting very annoying, and when friends come over to check it out I find myself saying "hurry and look while you can still see it". The mount has 2 handles screwing into each side of the scope, one handle with a ball-bearing for tightening, but even that doesn't do the trick, no matter how hard I tighten it. It's managable with a 25mm ep, but when I put in my 10mm, it's near impossible to center on an object.. Does anyone have any suggestions for fixing this problem?
     
  2. jcsd
  3. Mar 4, 2010 #2

    turbo

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    You need a counter-weight to balance the 'scope. It shouldn't be too tough to cobble one up.
     
  4. Mar 4, 2010 #3
    Yea last night I was pretty desperate and strapped a 5lb. dumbbell on it with my belt. It was good when I looked at things near the horizon.. but when I had to aim up, it was too heavy and kept drifting up. Are counter-weights a regular part of viewing with a dob for everyone else? If so.. damn. I need to save up for an eq mount.
     
  5. Mar 4, 2010 #4

    turbo

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    Consider buying a rail-mount and bolting it to the top of the Dob's tube. That way you can clamp a counterweight into the rail and slide it back and forth as needed. Orion may have something off-the-shelf. If not, it should be easy enough to make one at home.
     
  6. Mar 4, 2010 #5
    Is there an guide on what parts to get/how to assemble one anywhere? Sounds like a useful investment.. it'd just be nice to see how other people have done it before I go blow $40 at home depot.
     
  7. Mar 4, 2010 #6

    turbo

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    http://www.oreillynet.com/pub/h/3397

    This guy uses 19 oz magnets wrapped in duct tape. If your tube is steel, that would work fine. If not, check out telescope.com . That's Orion, and they have a dovetail mounting plate that you may be able to adapt to.
     
  8. Mar 4, 2010 #7
    Is there a way to mount my telescope to an eq mount?
     
  9. Mar 4, 2010 #8

    turbo

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    Yes, you can do that, but the mount is going to cost you way more than the entire Dob' cost. GEQ's large and massive enough to handle 10" Newtonian OTAs are expensive - especially if you up-size with the intention of adding guidescope, camera, etc.
     
  10. Mar 4, 2010 #9

    turbo

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  11. Mar 4, 2010 #10
    http://gibbscamerahouse.com.au/images/COLDOB10sm.gif [Broken]

    if you look at my scope, you'll probably notice that when extended, the actual "tube" part isn't near the middle of the scope.. if I mounted it with an eq, i don't think the fulcrum would be centered. i think i'd have the same balance issues unless you can see a way around it.
     
    Last edited by a moderator: May 4, 2017
  12. Mar 4, 2010 #11

    turbo

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    Most EQ mounts have a flat plate that accepts an adapter plate that you have to attach to your OTA near the balance-point. If you want a decent guide-scope later, you can install a dovetail rail on the OTA, and use the placement of the guide-scope to fine-tune the balance. You still might need supplemental counter-weights in instances where you want to use barlows and heavy EPs in your focuser, or attach a camera. It's not rocket science, but it's not always obvious what will work. I had a SC that I sometimes piggy-backed 35mm or medium format cameras on. I counter-balanced the OTA using plastic bean-bags full of lead shot, and attaching them temporarily with skinny bungies. It didn't look too high-tech, but it worked.
     
    Last edited by a moderator: May 4, 2017
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