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Help with Meade EQ mount

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11 replies to this topic

#1 Guest_**DONOTDELETE**_*

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Posted 20 December 2004 - 11:22 PM

This past weekend I began to take apart both of my GEM's for the refurbishing project.

I stopped short at the RA shaft and the drive.

Removing the drive will be straight forward...the problem is that I know there are a set of bearings inside the RA shaft housing.

I do not know if these were press fit with an arbor or can be removed with a puller (the goal is to remove the shaft).

Being very cautious, I decided to call Meade to get some information about the assembly of this portion of the mount.

I was very suprised with the response I received from their customer service staff.

After explaining my situation, I was told "that system is obsolete"

Wow, I would rather have turned aluminum, cast fitings and brass than the plastic that some of these companys call progress...less I digress.

Anyway, I explained that the Research Series GEM is the same as the current one offered on the Starfinder 16". I was then told that "nothing is interchangable".

I asked to speak to some one in the technical dept. and got dumped into voice mail.

:rant:
Granted, those that were on staff in the 80's when my system was built are probably gone, and those there now doubtless have any clue about the fine equipment that was produced here in the 80's. ( I am not slamming Meades products...just thier poor product knowledge)

I dont expect a detailed drawing, just an informed idea to help me out since the mount is the same.

It is not like I am asking them to support my old equipment, however, if it is the same GEM, they should have the info I need.

So here is some advice to those of you who have some modern scopes and mounts, order extra parts that will probably wear out, and a tech manual if it is available, otherwise you might end up with an "obsolete system"

Anyone with any experience with the older Meade GEM's that could help out here would be thanked.

#2 Guest_**DONOTDELETE**_*

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Posted 07 January 2005 - 11:18 PM

Hi Dan, just noticed your post for info. on the Meade RG mount. I have an old (later AC motor-type) Starfinder 16 mount. I'll have mine apart soon to replace the nylon RA thrust washer with a home-cut teflon washer. I suspect the whole RA shaft will pull out once everything from the clutch back is off the shaft (although the threaded plug on the front of the dec housing makes me suspect there may be some kind of fastener behind the dec shaft) leaving the bearings in place in the housing. In any case unless something really weird has happened it's doubtful you'll need to pull the RA ballbearings. They're permanently lubed Sealmasters, made to stand up to a whole lot more load, exposure and RPM's than they'll ever take in
a lifetime's use in a telescope mount. If there's stiction in the system I'd be looking (as indeed I shall, lol) at the nylon thrust washer up front. Good luck!

#3 Guest_**DONOTDELETE**_*

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Posted 10 February 2005 - 03:13 PM

Hi Dan and Roadrash,

Were you able to get the RA shaft out? That "threaded plug on the front of the dec housing" is seriously stuck on my mount. I don't want to strip it. Does it need to come out to remove the shaft?

Also has anyone found better replacements for the plastic bushings?

Thanks for any help.
Mike

#4 Guest_**DONOTDELETE**_*

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Posted 11 February 2005 - 12:32 AM

Hey Mike...Roadrash

I tackled my smaller 800 series mount first.

There was some slight tapping required to get the polar shaft out.

And there was in fact a bearing in the polar housing on this smaller mount.

All is well and the rebuild went well. No need to remove the bearing....just carefully fed some grease into the race for good measure.

As far as the threaded plug goes, I have not tried to remove mine yet, however, I am thinking that it would not have to be removed to pull the dec shaft.

You might want to try some penetrating oil around the threads over several days and let it soak in.

Best to be slow when working on these older mounts as the spare parts are few and far between.

If schedule allows this weekend, I will try to take a peek at what is behind the plug (if mine will loosen) :shocked:

#5 Guest_**DONOTDELETE**_*

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Posted 12 February 2005 - 11:23 PM

Thanks Dan,

I think I will wait until next time to remove the screw. I would hate to strip it or worse when I have only had the scope out once so far. But any info you can give would be great. I got the rest cleaned up nice and re-lubed and want to do a few other mods. Hope yours works out for you.

Thanks for the help.

Mike

#6 Guest_**DONOTDELETE**_*

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Posted 13 February 2005 - 10:25 PM

Mike,

I began to break down the EQ assembly on the 880 today.

The allen head pulg came out easily for me fortunatly.

Behind it I found that there is another allen head inside of the dec housing.

This allen head is what holds the polar shaft to the dec. housing.

I found no need to take this apart as I will be masking off the flat teflon bearing surface and shaft before bead blasting the dec. housing.

I will only need to blast the last 6" of polar shaft as this was the only portion with rust.

The dec. shaft is another story.

I could post a pic or two if you would like to see what you are in for.

#7 Guest_**DONOTDELETE**_*

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Posted 14 February 2005 - 01:26 AM

Dan,

A picture of the polar shaft to DEC attachment would be excellent if you have a chance.

Thanks,
Mike

#8 Guest_**DONOTDELETE**_*

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Posted 15 February 2005 - 12:52 AM

Mike, Here is a series for you.

You can see how the weather oxidzed the aluminum....the bead blast will smooth and even out the finish.

Attached Thumbnails

  • 343947-Copy of 880 001.jpg


#9 Guest_**DONOTDELETE**_*

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Posted 15 February 2005 - 12:59 AM

Here is a shot of the dec housing with the allen plug removed. You can just make out the allen head inside. That is what retains the polar shaft to the dec housing.

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  • 343952-Copy of 880 003.jpg


#10 Guest_**DONOTDELETE**_*

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Posted 15 February 2005 - 01:04 AM

here is one of the polar housing and sealmaster bearing where the machined dec surface rides with the teflon washer.

The surface looks rough but is machined smooth.

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  • 343958-Copy of 880 012.jpg


#11 Guest_**DONOTDELETE**_*

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Posted 15 February 2005 - 01:11 AM

This is the drive end of the polar housing and it's sealmaster.

Hope these help. ;)

Attached Thumbnails

  • 343962-Copy of 880 008.jpg


#12 Guest_**DONOTDELETE**_*

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Posted 15 February 2005 - 05:06 PM

Hi Dan,

Very helpful! Thanks for taking the time to do that.

Mike


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