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Reworking an old Meade Starfinder mount

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#26 Tom Stock

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Posted 26 August 2021 - 11:09 AM

Well I finished restoring my old starfinder mount. 

 

I found that I could get replacement bushings (which were missing) from mcmastercarr.com, and I sanded all the rust off the dec shaft.  I may replace the shaft eventually but for now it's fine.  I also managed to get the DC drive working. Most of the set screws were missing, so I located those also.

 

I purchased a Meade SN-6 to put on this mount for now which should work for short exposure photometry images.

 

I needed to replace the 25lb counterweight.  I found a 11lb counterweight in my junk box, but it was for a 3/4" shaft, so I chucked it up in my mini lathe and bored out the center to fit a 1" shaft and painted it black.

 

I've always wanted one of these mounts. I remember drooling over photos of it in S&T in the early 90s when I got my first dob.  I have a thing for manual RA driven german mounts on pedestals.  I'll also be making a larger dec circle, but I haven't been able to do that yet as I broke my leg and required surgery so I've been locked up for weeks.

 

I have a 10" mirror blank on the way, and will eventually by grinding and polishing a the mirror for a 10" reflector which will also land on this mount.

 

Some day I really hope to find a Meade RG mount somewhere near Florida.  Just throwing that out there!

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Edited by Tom Stock, 26 August 2021 - 11:17 AM.

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#27 Garyth64

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Posted 26 August 2021 - 02:42 PM

That looks very nice. Good job.



#28 Tom Stock

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Posted 01 September 2021 - 05:18 PM

There was a lot of drag on the shafts.  It took a lot of effort to rotate either shafts.  So I took it all apart, and it did come apart very easily.
I found a black grease on the plastic bushings, and cleaned it all up.  I replaced the old grease with some pink stuff my dad had.  That didn’t work, there was still too much friction.  I took it all apart again and cleaned up the pink stuff.  Just for the heck of it, when I reassembled it this time, I didn’t put anything on the bushings at all.  It actually seemed to help, but still not good enough, and took it all apart once again. 
When I removed the bushings and cleaned the housing, I noticed that there were some dimples made with a punch where the bushings sat.  I guess these were to keep the bushings in place.  I felt that they were pinching the bushing and causing too much friction, so I filed them smooth.
After putting it all back together, I noticed a big difference in the shaft movement.  It was much better.  And after another disassembly I put a little light weight oil on the bushings.  That made another big improvement.
I’d like to replace the plastic bushings with metal ones.

 

This mount has a large RA setting circle, but a small DEC circle.  I had larger 6" setting circle so I replaced the small one.  I came up with a bushing with a 1" ID, and a 1-1/2" OD, and it will work fine.  A minor problem was that there wasn’t an indicator for the large DEC circle.  I made a 6" semicircle, drilled and tapped a hole on the housing, and bolted the new indicator to the housing.

 

attachicon.gifsetting circles.jpg

attachicon.gifdrill and tap.jpg

attachicon.gifdec indicator plate.jpg

 

More to come . . .

What did you use to color the dec circle black while leaving the engravings in the white?

 

Alumiblack and white engraving marking crayon?


Edited by Tom Stock, 01 September 2021 - 05:21 PM.


#29 Garyth64

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Posted 01 September 2021 - 05:30 PM

The dec circle was untouched.  It was that way when I purchased it.



#30 Garyth64

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Posted 01 September 2021 - 05:32 PM

I will be selling the belt drive motor that Geo made up, and the electronics, with the gear, and black housing.

 

I also will be selling the Starfinder mount, as the picture way back showed.  It has an AC CD, that was original to those type mounts.

It's a nice mount, I just have others so I won't be using it.


Edited by Garyth64, 01 September 2021 - 05:35 PM.


#31 Tom Stock

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Posted 11 September 2021 - 01:05 PM

The dec circle was untouched.  It was that way when I purchased it.

The new one not the old one... how did you blacken it?

Attached Thumbnails

  • 9DCCC089-40CE-41BF-A657-525F51F8F182.jpeg
  • 35902D33-7722-4F89-9802-C3C10DB0B9A2.jpeg

Edited by Tom Stock, 11 September 2021 - 01:06 PM.


#32 Garyth64

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Posted 11 September 2021 - 02:26 PM

I forgot about the unpainted one.  I sold it a long time ago, and kept the painted one.



#33 Tom Stock

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Posted 12 September 2021 - 09:14 AM

I forgot about the unpainted one.  I sold it a long time ago, and kept the painted one.

Ah ok didn't realize they were two difference circles.

 

Thanks




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