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Old 20-04-2013, 06:37 PM
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White Rabbit
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Keeping the weight east bias after meridian flip, solution!!!?

Hi guys.

I've seen many discussions here about how to keep you mount consistently east heavy but never really seen any solutions.
This is certainly not my idea, in fact I got it from the losmandy yahoo user group and thought others may find it useful.

I set this up today, haven't tested it yet but will once I get some clear weather.

All up the mod cost about $15 from bunnings, it's a very simple solution.

Basically it's a pendulum with a 1kg weight on the east side so that it constantly pulls to the east regardless of which side of the mount the scope is on. I've used some vb cord and wrapped it around and tied it to the RA axis. I then used a metal arm with a roller wheel at the end to ensure the cord winds off and on the RA axis evenly and doesn't snag on anything. I then used a C clamp to secure the arm to the mount.

Anyway it's kind of hard to describe, have look at the images they will hopefully explain it better than I did.

Sandy
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Last edited by White Rabbit; 20-04-2013 at 06:56 PM.
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Old 20-04-2013, 06:41 PM
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Sorry I'm trying to attach images from my ipad and its not going well.
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Old 20-04-2013, 06:50 PM
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bert (Brett)
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Quote:
Originally Posted by White Rabbit View Post
Hi guys.

I've seen many discussions here about how to keep you mount consistently east heavy but never really seen any solutions.
This is certainly not my idea, in fact I got it from the losmandy yahoo user group and thought others may find it useful.

I set this up today, haven't tested it yet but will once I get some clear weather.

All up the mod cost about $15 from bunnings, it's a very simple solution.

Basically it's a pendulum with a 1kg weight on the east side so that it constantly pulls to the east regardless of which side of the mount the scope is on. I've used some vb cord and wrapped it around and tied it to the RA axis. I then used a metal arm with a roller wheel at the end to ensure the cord winds off and on the RA axis evenly and doesn't snag on anything. I then used a C clamp to secure the arm to the mount.

Anyway it's kind of hard to describe, have look at the images they will hopefully explain it better than I did.

Sandy
This is done at professional observatories as well. When I visited palomar, I got to have a look at the 48 inch Schmidt that has a similar setup to control backlash.
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Old 20-04-2013, 09:30 PM
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mithrandir (Andrew)
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Sorry I'm trying to attach images from my ipad and its not going well.
See Jared's images to see how he did it. It looks like he used the cover bolts for the worm case to attach the guide roller.
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Old 20-04-2013, 10:02 PM
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See Jared's images to see how he did it. It looks like he used the cover bolts for the worm case to attach the guide roller.
I thought about doing that today, but then thought better of it just in case it adds vibration that translates through to the worm as PE.there are a few other locations on the mount to fasten the pulley wheel to. I'll perhaps think about exploring some of the later on down the track. I have that many wrinkles to iron out of this mount I think I need to get it completely functional before I modify anything so I can isolate any issues that arise. I'm getting there one chip at a time.

Thanks.
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Old 20-04-2013, 11:01 PM
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I had a 350g stainless weight machined for me. has an allen head locking bolt. I just slide it down the counterweight shaft if telescope is on west side, or up an inch or so if telescope is on east side. Sure, isn't "set and forget" but works.
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