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Alt gear slipping on Meade DS2xxx mount - fixable?

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#1 TerryB

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Posted 21 June 2013 - 12:59 PM

Hi everyone,

The Meade DS2xxx style mount under my year-old StarNavigator 102 refractor has begun slipping down after I release any of the directional navigation buttons on the controller. At 110X, for example, target stars will drop about half the field of view. As you can imagine this is extremely frustrating.

While I have considered binning the whole thing, I would like to do all I can to tune this relatively unused mount before I decide to replace it. Trouble is, I don't have the mechanical skill or experience with telescopes to suss out the problem.

Are there some basic steps I can take to return this mount to its best possible performance?

Thanks in advance,
Terry

#2 zerro1

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Posted 21 June 2013 - 09:58 PM

what controler/handbox does it use? is it an Autostar computer type or just a basic directional keypad?

#3 jgraham

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Posted 22 June 2013 - 03:44 PM

You can find very helpful information about the DS-2000 series on Mike Weasner's Mighty ETX Site. A common problem with the DS-2000 is that grease slowly works its way into the clutches. Every couple of years they need to be taken apart and cleaned. I have 2 of these mounts and they have given me many years of excellent service.

#4 TerryB

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Posted 22 June 2013 - 04:46 PM

Robert,

It's the AudioStar controller, which I understand is like the 497 controller, but with audio features.

#5 TerryB

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Posted 22 June 2013 - 04:55 PM

Thanks, John.

I did have the altitude gear assembly apart recently and did not notice any greasy parts, but I will check again once I get a chance to test some adjustments I made yesterday after writing my post. All I did was remove my telrad which had been preventing me from adjusting the balance of the OTA in the mount. I also re-trained my drives, though I had done that quite recently anyway. Now all I need is a clear night to try my luck.

I`m thinking that if nothing improves it`ll suggest that my reassembly of the altitude gear assembly is likely to blame for this wondering gear system. It does seem like I now have to tighten the clutch more to secure it sufficiently for tracking.

#6 Geo.

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Posted 23 June 2013 - 01:59 PM

Well, if the Alt axle isn't broken (a common failure) you're in luck. Your Alt worm may not be properly engaging the worm wheel. The worm and drive are held in postion by a short stout spring, but the drive's mounting screws may have to be lossened for the spring to take up the slack.

You have to pull the plastic cover off the inner arm to get at the drive. The retaining screws are under the Alt setting circle.

Another common problem is that the circlip that retains the pressure plate (a washer) comes out of its land and prevents the dog from engaging the worm wheel.

Good luck

Attached Files



#7 TerryB

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Posted 23 June 2013 - 04:53 PM

George,

Thanks very much for the pics! They should be helpful once I get my gears apart.

I disassembled my altitude gear housing, at least partially, to get a look at the worm gear. Since I can't seem to post an image from a Dropbox URL here, I'll try to share it with this link

If you can view the picture, it shows the worm gear firmly engaged with the gear wheel. I would disassemble it further, but I can't work out how to do that properly. I suspect it involves twisting the flat-sided bolt in this picture but I don`t want to start strong-arming something if I don`t need to. Please let me know what you think.

Many thanks,

Terry

#8 Geo.

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Posted 25 June 2013 - 01:40 PM

Yes, that looks good. If you press the axle with your thumb the assembly will push out the other side (from that in your piccie). Take a close look at the retaining ring to be sure it's in its land. Tightening the clutch too much can push it out of the land.

#9 TerryB

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Posted 27 June 2013 - 08:08 PM

Thanks to all the guidance here, I managed to tear the gear apart and put it back together pretty successfully. Nothing seemed amiss with the gear teeth, and the retaining clip was seated where it belonged. So, the jury is still out on the wondering altitude gear until I can get some clear skies to test things out on. Thanks to all.

Terry






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