30 replies to this topic

[Garyth64]

I believe that the mounts for the Meade 6" and 8" telescope were the same in their time period.  I do know know their time period.

 

About 3+ years ago I purchased a red Meade 826, it is identical to the Tasco 38T.  I cleaned it up, tested and had the primary recoated,  put in a larger Antares secondary, changed the secondary support and spider, and changed the focuser to a similar one.

But I never messed with the mount.

 

Last year, I purchased a basket case white Meade 826.  I repaired a hole made in the tube, cleaned the mirrors, but it still needs some work to be usable.

I never messed with its mount either, until a couple of days ago.

 

I brought both mounts in from the garage.  The one on the left is the mount for the white Meade, and on the right is the mount from the red Meade. 

 

 

I wonder which mount was a first design?  I think you can already see a couple of differences.  The castings are basically the same.

 

In this picture, the RA shaft is longer on the red Meade mount (the black one), because the RA circle has been moved.

 

 

In this picture, you can see the the black mount has a latitude adjustment:

 

 

 

 

The clock drive on the red Meade black mount works fine.  (Well, I can hear it run.)  The unpainted mount's CD does not work.  Water got into the housing sometime in its life.

 

I decided to take the unpainted mount apart.  First thing was to remove the ring hear and clutch assembly.  The last section would not move, so I pulled it off like a gear:

 

 

 

In doing this, I was afraid I would break the part in trying to get it off, but it did come off.  The collar was also difficult to take off.

Before I pulled the shaft out of the housing, I filed and sanded the rusty end of the shaft.  The shaft came out easily.

I was surprised to see that there was a bearing at the top of the housing.  I didn't know these mounts had a bearing.  I thought they only had sleeves like the Star Finder mounts.

 

 

I didn't take any more pictures.  It was just doing some cleaning and re-assembly. I also took some fine sand paper and sanded the end of the shaft like I was polishing  the end of a boot. All traces of the surface rust disappeared.  Before I re-installed the clutch assembly, the RA shaft would easily swing back and forth like a pendulum on its own.

Even though the CD is missing from this mount, it still has the slo-mo adjustment, which is the knob sticking out of the CD cover. This mount could still be used manually.

 

Next thing to clean now will be the pedestal:

 

Edited by Garyth64, 02 March 2025 - 08:35 PM.

[deSitter]

IIRC the Meade Newtonians go back to 1977, and there was a "Bulletin 68" describing the new series. The 6" and 8" came out simultaneously, on the same mount. I believe it was the silver version here.

 

Meade were copying what they regarded as their main competition, the Criterion RV-6 and RV-8, which also were f/8 and f/6 respectively, and used the same mount.

 

-drl

Edited by deSitter, 02 March 2025 - 04:08 PM.

[tim53]

I worked on the “white meades” in 1978 and 1979.  The red meade was built for Tasco alongside the white Meades.  I worked on a few of these in 1982.

[Garyth64]

Here's one of the 826 mounts placed on a tripod.

I put a 3" Selsi 247 on it, and it makes a solid combination.  It's almost over-kill, as the mount can handle a lot more weight.

 

 

This mount doesn't have a CD at this time, but it works great in manual mode.  These mounts had a control that could advance or retard an object in the FOV to center it.  These CDs must have a clutch built in them to allow for this adjustment.  Not all CDs are able to do this.  Maybe it is unique to the 826 mounts.

I did some experimenting and found out some other things.

 

I took a CD from my Starfinder mount, as they look identical and attach in the same way.  However, the CD on the Starfinder mount isn't able to be advanced with a control like the 826 mounts have.  I tried, it didn't work, and I removed it.

Also, as I mentioned before, these mounts have a bearing on the upper end of the housing.  On this mount, the lower end only rides on the machining of the housing itself.  In the newer mount, from the red Meade, the lower end of the housing has a plastic sleeve that the 1" shaft rides in.

 

As I said, the CD on this 826 mount does not work.  I lived part of its life in water, and the inside of the motor was rusted and frozen up.

Maybe there still is hope . . .

 

The other day as I was watching some HO train videos, a guy was working on an old HO engine.  The engine did not run, and was rusted to the point it was frozen and would not work.

The guy had an old trick of soaking rusted parts in vinegar.  He says the vinegar, which is 5% acidic, breaks down the rust.  After 3 days, he was able to clean the rusted parts and get the little HO engine working again.

 

So back to the 826 motor . . . It's been soaking in vinegar for 2 days, and so far, some of the parts and the gear box are turning freely.  Tomorrow, I'll remove the motor from the vinegar, put it back together, and see if it will run.  The motor  did come apart in 3 sections.

 

If not, does anyone have a spare 826 motor in their junk boxes?

Edited by Garyth64, 05 March 2025 - 08:39 PM.

[NinePlanets]

Vinegar will eat copper wire. I'd get it out of there and soak it in kerosine or Stoddard solvent overnight, Gary.

[Garyth64]

Thanks Nine Planets for the heads up, I didn't know that.  I think no harm has been done.  

 

This morning I did pull the motor parts out of the vinegar.  I rinsed everything off with water and baking soda to neutralize the vinegar.

 

I was surprised to see that the motor cleaned up fairly good.  Some of the corrosion I scrapped off, and rinsed a little more.

 

Here's the disassembled parts before I put them back together:

 

 

The gear box really cleaned up nice, and the "flywheel" turns freely.

 

I put it all back together, except for the cover, and I plugged it in.  The motor runs very good and quietly, but the output shaft, that would go to the worm gear, does not move.

I don't know why it would do that.  I'll have to look closer at the inside of the gear box.

[Garyth64]

I assembled the motor without is metal cover and plugged it in.  I could see the flywheel whirling away.  Using a flashlight to see inside the gearbox I could see that the first gear that engages the flywheel has some teeth missing.  So, this motor is unusable.

[deSitter]

I assembled the motor without is metal cover and plugged it in.  I could see the flywheel whirling away.  Using a flashlight to see inside the gearbox I could see that the first gear that engages the flywheel has some teeth missing.  So, this motor is unusable.

Argh. Why didn't people just use brass gears? Sigh.

 

-drl

[Garyth64]

Argh. Why didn't people just use brass gears? Sigh.

 

-drl

I may take the entire gear box apart to see all what is in it.  In looking at it from the outside, all the gears do look like brass.  I'll know soon.

[Garyth64]

deSitter, you are correct.  All the brass gears look good.  The very first gear from the motor is not brass, and it failed.

 

In the picture you can see the damaged teeth:

 

 

 

It looks like a couple other gears aren't brass either.

Edited by Garyth64, 06 March 2025 - 06:43 PM.

[gelkin]

I once bought a 4” Unitron drive that didn’t work for cheap. I found inside a similar gear that was stripped. I went to a hobby shop that had a lot of RC cars and parts and found a gear to replace it. As long as the teeth mesh you can drill the shaft hole to fit. At least it worked in this case. Unitron drives are valuable enough to be worth the effort.

[deSitter]

I once bought a 4” Unitron drive that didn’t work for cheap. I found inside a similar gear that was stripped. I went to a hobby shop that had a lot of RC cars and parts and found a gear to replace it. As long as the teeth mesh you can drill the shaft hole to fit. At least it worked in this case. Unitron drives are valuable enough to be worth the effort.

Yes if anything can be remade it is a gear. So don't quit! I just don't understand why all gears in this context are not brass. How much can it cost to use brass over plastic?

 

-drl

[Garyth64]

I like the size of this Meade mount.  It may be a while before I find a CD for it, and I'm really not sure I'd be happy with the mount in manual mode.

So I switched out some parts.  I took the CD off the Starfinder mount and put it on the 826 mount. I also switched the worm gear.  Easy swap.

 

Right now, the CD has been running for about an hour, and by the RA setting circle, it's right on time.

 

So for the time being, I'm satisfied

[Terra Nova]

I had the bigger 826 GEM. It was heavy and quite capable. Really not suited for what I needed at the time. It lacked slow motions and was more than what I needed so I donated it to my club. 

Attached Thumbnails

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[Bomber Bob]

It lacked slow motions and was more than what I needed so I donated it to my club.

 

I like the Meade StarFinder EQs so much that I bought 2:

 

 

I love No Wires; and, each drive runs for hours on a 9V Duracell.   

 

But yeah, the lack of a DEC slo-mo... is a pain.  I bought a brass gear set from Sean with plans to adapt it to my Tall SF (for my big refractors)... just gotta take the time, and turn my Dremel loose on it.

 

 

[NinePlanets]

Dec slomo's for the Meade mounts were an option you could buy. I installed a number of them for clients.

[Terra Nova]

It lacked slow motions and was more than what I needed so I donated it to my club.

 

I like the Meade StarFinder EQs so much that I bought 2:

 

Meade SF - Pedestal Restores S03 (Both).jpg

 

I love No Wires; and, each drive runs for hours on a 9V Duracell.   

 

But yeah, the lack of a DEC slo-mo... is a pain.  I bought a brass gear set from Sean with plans to adapt it to my Tall SF (for my big refractors)... just gotta take the time, and turn my Dremel loose on it.

Mine was AC, you can see the wire in my pic.

[CHASLX200]

I had the bigger 826 GEM. It was heavy and quite capable. Really not suited for what I needed at the time. It lacked slow motions and was more than what I needed so I donated it to my club. 

My 2nd 826 mount with no drive was very good and my fav 1" shaft mount.

Attached Thumbnails

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Edited by CHASLX200, 09 March 2025 - 04:04 PM.

[Garyth64]

I had the bigger 826 GEM. It was heavy and quite capable. Really not suited for what I needed at the time. It lacked slow motions and was more than what I needed so I donated it to my club. 

Terra, what do you mean by the bigger GEM mount?  What is is bigger than?

 

Do you mean it is bigger than the mount in #4?

[Garyth64]

It lacked slow motions and was more than what I needed so I donated it to my club.

 

I like the Meade StarFinder EQs so much that I bought 2:

 

Meade SF - Pedestal Restores S03 (Both).jpg

 

I love No Wires; and, each drive runs for hours on a 9V Duracell.   

 

But yeah, the lack of a DEC slo-mo... is a pain.  I bought a brass gear set from Sean with plans to adapt it to my Tall SF (for my big refractors)... just gotta take the time, and turn my Dremel loose on it.

I like those StarFinder mounts too.  I have one, but have used it very little.  I think I might be decommissioning the one I have as I have already removed its CD.  The mount also has a DEC slo-mo.  So if I'm not going to be using that mount, I can give you the slo-mo control.

 

 

Just let me know and I'll send it to you. Just pay for postage. 

[Bomber Bob]

Thanks, Gary!!

 

I wasn't looking forward to additional carving on my Tall MSF... one slip, and Yikes!

[Garyth64]

Thanks, Gary!!

 

I wasn't looking forward to additional carving on my Tall MSF... one slip, and Yikes!

? I don't understand what you mean.

[Bomber Bob]

To use the gears & hardware that I already have, I'd have to modify the DEC casting, and setting circle.  It wouldn't fit the same way as the Meade Kit.

[Garyth64]

I guess I didn't know the extent of what you had done to your mount.

[Bomber Bob]

Nothing major so far.  I did cut off the curved cradle ends (for 6" / 8" Newts), and adapt the original top plates to modern versions -- these had lots of holes for all sorts of rings & spacings: