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Byers Drive C8 Disassembly

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#26 Geo31

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Posted 27 June 2017 - 10:18 PM

I didn't take enough pictures. Yup. If the mount was all together sitting on a table it goes below the dial with the RA numbers (that you flattened). It's there just to put friction against that RA dial so it doesn't spin freely. A little grease on the spring helps glue it in place while you are working.

 

Get the non-lithium grease. The tube I have is grey. I think the lithium stuff is in a white tube?

Well....

 

Started putting it back together tonight.  In fact, twice I had it nearly done, but the RA circle didn't have enough friction.  I think I'm going to need to disassemble and use a thicker grease under the RA circle.

 

I also need to chase the threads for the machine screws that hold the clutch in place.  I can see how they loosened up and fell out.  May even need to get longer screws.  I think the thread lock would hold.  For a while.  But it's not the right solution.  The factory screws are 7/8" long, so it will be easy to get 1" screws.  That should be enough extra hold with the thread lock.  I don't think I could get 1 1/4" screws in the bosses.  But maybe.  I'll probably buy a set of both.  God knows they are cheap enough.

 

So close.....



#27 NMBob

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Posted 28 June 2017 - 06:57 AM

Huh. Never had a loose RA circle. They've always ended up with just the right feel. Maybe you flattened it too well! :) Some people do use axel grease to make things stickier. There are NyoGel products that are made to make things feel smooth and silky when you turn them, but it's kinda hard to find them in small quantities. I got small jars of the 760G version for my MagLite flashlights from ebay. I got a tube of 767A to play around with, but it makes it feel like there is sand in the works when it gets down below 32F. When it warms back up it's fine. Weird.

 

boltdepot.com has all the odd lengths of things that you probably won't find at Ace. I've ordered a lot of the <3/8" sizes from them.

 

Those clutch screws screw into the cast aluminum, so the threads are kinda weak. You could use JB Weld. Just put a small dab on maybe just the end of the threads of the screws and put them in. That should "fix" the missing/damaged threads and you should still be able to unscrew the screws if you take it apart again.


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#28 deSitter

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Posted 28 June 2017 - 01:28 PM

 

I didn't take enough pictures. Yup. If the mount was all together sitting on a table it goes below the dial with the RA numbers (that you flattened). It's there just to put friction against that RA dial so it doesn't spin freely. A little grease on the spring helps glue it in place while you are working.

 

Get the non-lithium grease. The tube I have is grey. I think the lithium stuff is in a white tube?

Well....

 

Started putting it back together tonight.  In fact, twice I had it nearly done, but the RA circle didn't have enough friction.  I think I'm going to need to disassemble and use a thicker grease under the RA circle.

 

I also need to chase the threads for the machine screws that hold the clutch in place.  I can see how they loosened up and fell out.  May even need to get longer screws.  I think the thread lock would hold.  For a while.  But it's not the right solution.  The factory screws are 7/8" long, so it will be easy to get 1" screws.  That should be enough extra hold with the thread lock.  I don't think I could get 1 1/4" screws in the bosses.  But maybe.  I'll probably buy a set of both.  God knows they are cheap enough.

 

So close.....

 

Perfect application for this fantastic damping grease. I used this everywhere. It's even good on eggs.

 

https://www.amazon.com/dp/B00BOMKGPW

 

-drl


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#29 NMBob

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Posted 28 June 2017 - 02:05 PM

In some places that 760G is advertised as being for things like flashlights, because it is conductive. I stuck my Fluke probes in it and it is not conductive. I'm not sure what they are talking about. Made all of my flashlights work a lot better, though. Good stuff.

 

Maybe I will try it on my test nut and bolt that I put a little on and throw in the freezer. The 767A definitely didn't like that.

 

Bob



#30 Gil V

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Posted 28 June 2017 - 05:20 PM

Superlube worked great for me when I rebuilt a couple of Dynamax mounts. The DEC movement is as smooth as it has ever been - perhaps too smooth lol. These scopes have aluminum against aluminum throughout the DEC mounting surfaces.
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#31 Geo31

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Posted 29 June 2017 - 06:33 AM

Superlube worked great for me when I rebuilt a couple of Dynamax mounts. The DEC movement is as smooth as it has ever been - perhaps too smooth lol. These scopes have aluminum against aluminum throughout the DEC mounting surfaces.

I used the Super Lube on everything.  I think it's a bit too slick on the RA circle.  I hate to buy a tub of axle grease because I either have a tub somewhere (the joys of moving twice in a short amount of time) or threw one out (prior to moving).  But, it's cheap enough, so I'll probably buy some to use for the RA circle.

 

Funny thing is it felt perfect upon assembly, but rotating the mount in RA caused the RA circle to slip.  I'll look at it a little more closely this weekend.



#32 Geo31

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Posted 29 June 2017 - 06:35 AM


Those clutch screws screw into the cast aluminum, so the threads are kinda weak. You could use JB Weld. Just put a small dab on maybe just the end of the threads of the screws and put them in. That should "fix" the missing/damaged threads and you should still be able to unscrew the screws if you take it apart again.

I may do that if I have to.  The bosses look to be deep enough to use a longer screw, so I'll try that first.  A tap that size shouldn't be too expensive.



#33 NMBob

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Posted 29 June 2017 - 08:25 AM

Funny thing is it felt perfect upon assembly, but rotating the mount in RA caused the RA circle to slip.  I'll look at it a little more closely this weekend.

 

 

You mean like not follow the forks when you move them? That kinda slip? That big C spiring is supposed to keep the RA circle in contact with the fork part, but allow the circle to be turned by hand. I wonder why it is not pushing hard enough? The thicker grease on the top side may help. Like I said, you made the RA circle too flat! :) I just put a tiny amount of grease on those parts. That may have made the SuperLube more sticky than slippery.

 

You could probably just go to an auto shop and ask to barrow a cup of grease. Just take a little container.


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#34 Geo31

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Posted 29 June 2017 - 10:49 AM

 

Funny thing is it felt perfect upon assembly, but rotating the mount in RA caused the RA circle to slip.  I'll look at it a little more closely this weekend.

 

 

You mean like not follow the forks when you move them? That kinda slip? That big C spiring is supposed to keep the RA circle in contact with the fork part, but allow the circle to be turned by hand. I wonder why it is not pushing hard enough? The thicker grease on the top side may help. Like I said, you made the RA circle too flat! smile.gif I just put a tiny amount of grease on those parts. That may have made the SuperLube more sticky than slippery.

 

You could probably just go to an auto shop and ask to barrow a cup of grease. Just take a little container.

 

Yes, exactly.  When I moved the fork park, the RA circle was slipping and not following the fork part.

 

Thinking some more about this, perhaps the spring is too flat.  I have a couple of things I could try.  I could make multiple small waves in it, or even just one.  What's funny is the resistance of movement of the SC feels about right, but with everything together, there are issues. 

 

It's hard for me to spend a lot of quality time on this stuff during the week and the other day, when it was clear I needed to at least partially disassemble, I just packed it in after the partial disassembly.  I'm off tomorrow and may tinker just a bit before leaving the house.



#35 TOM KIEHL

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Posted 29 June 2017 - 10:58 AM

PM sent



#36 NMBob

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Posted 29 June 2017 - 11:11 AM

Thinking some more about this, perhaps the spring is too flat.  I have a couple of things I could try.  I could make multiple small waves in it, or even just one.  What's funny is the resistance of movement of the SC feels about right, but with everything together, there are issues. 

 

It's hard for me to spend a lot of quality time on this stuff during the week and the other day, when it was clear I needed to at least partially disassemble, I just packed it in after the partial disassembly.  I'm off tomorrow and may tinker just a bit before leaving the house.

 

 

Possible. You might try and put a little bend in it. Use something like a coffee can and bend it just enough so it doesn't lay flat on a table. If it is too much of a bend it might start to grind into the RA circle.

 

I know. These day jobs just suck up a lot of perfectly good time. :)


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#37 Geo31

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Posted 03 July 2017 - 07:47 AM

I didn't take enough pictures. Yup. If the mount was all together sitting on a table it goes below the dial with the RA numbers (that you flattened). It's there just to put friction against that RA dial so it doesn't spin freely. A little grease on the spring helps glue it in place while you are working.

 

Get the non-lithium grease. The tube I have is grey. I think the lithium stuff is in a white tube?

Actually, I think the spring goes above the dial.  That seems to have made everything come together right.  Dead-on.

 

It certainly complicated the assembly some.  Needed three hands to put the slo-mo gear/RA SC assembly together, but with some careful effort it wasn't too bad.



#38 Geo31

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Posted 03 July 2017 - 08:07 AM

OK, as noted in my previous post, I finally have the scope back together.  Once I got the spring in the right position, everything worked great.  What was happening is the center section that the forks bolt to was riding on the RA SC and dragging it.  Putting the spring on top of the RA SC gave the necessary space and I think also kept the pinion gear from the slo-mo from dragging as well.  A couple of drops of super glue put the window back in place.

 

I bought some black socket head cap screws and black washers to attach the forks, simply for looks.  Turns out I bought a bit too short so I put it back with the original hex heads and will go back and get longer socket head screws.

 

The reassembly was pretty straight-forward actually.  The only real trick in disassembly and assembly is getting the main gear past the worm.  It has some play, so it works OK, but it really takes a little care.

 

I need to test the optics next clear night.  I could have last night, but was just too tired and the atmosphere was really soupy anyway, even though it was "clear."  I'm guessing there may be come collimation issues.

 

Pics to follow as I get them sorted out.



#39 NMBob

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Posted 03 July 2017 - 08:17 AM

 

I didn't take enough pictures. Yup. If the mount was all together sitting on a table it goes below the dial with the RA numbers (that you flattened). It's there just to put friction against that RA dial so it doesn't spin freely. A little grease on the spring helps glue it in place while you are working.

 

Get the non-lithium grease. The tube I have is grey. I think the lithium stuff is in a white tube?

Actually, I think the spring goes above the dial.  That seems to have made everything come together right.  Dead-on.

 

It certainly complicated the assembly some.  Needed three hands to put the slo-mo gear/RA SC assembly together, but with some careful effort it wasn't too bad.

 

OH NO! I'm sorry! I've only done three of these in the past few months, so that tells you how good my brain is. :) You're right...you undo the 3? screws, a ring pops off, and then you hear the spring come loose UNDER the RA dial WITH IT UPSIDE DOWN.

 

I'll shut up now.


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#40 Geo31

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Posted 03 July 2017 - 09:02 AM

 

 

I didn't take enough pictures. Yup. If the mount was all together sitting on a table it goes below the dial with the RA numbers (that you flattened). It's there just to put friction against that RA dial so it doesn't spin freely. A little grease on the spring helps glue it in place while you are working.

 

Get the non-lithium grease. The tube I have is grey. I think the lithium stuff is in a white tube?

Actually, I think the spring goes above the dial.  That seems to have made everything come together right.  Dead-on.

 

It certainly complicated the assembly some.  Needed three hands to put the slo-mo gear/RA SC assembly together, but with some careful effort it wasn't too bad.

 

OH NO! I'm sorry! I've only done three of these in the past few months, so that tells you how good my brain is. smile.gif You're right...you undo the 3? screws, a ring pops off, and then you hear the spring come loose UNDER the RA dial WITH IT UPSIDE DOWN.

 

I'll shut up now.

 

Hey, no sweat.  Just knowing I was working with a net was a BIG help in having confidence going forward.  I've got the pics downloaded, adjusted, and ready to post.  Hopefully they will help someone else going forward.



#41 Geo31

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Posted 03 July 2017 - 09:14 AM

Here is the finished scope.  If you remember, it was all bent to snot around the 23 hour mark.  :grin:

 

bLbm3o3.jpg

 

And here is the big pic of the assembled scope.  And I wasn't even more efficient than the factory (no left over parts):

 

pko9eeN.jpg

 

The blue slotted channel is for weights.  It's an extruded aluminum channel often used by woodworkers for projects and the slot fits a standard "T" bolt.  The mounting bracket on the mirror end was made from aluminum bar and hand bent to fit the curve of the cell.  The mounting on the other end is and off-the-shelf bit I found at the local hardware store 0.25" thick.


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#42 Geo31

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Posted 03 July 2017 - 09:20 AM

OK, so here's a couple of pics of the base.

 

First the almost raw base.

 

vUg8p87.jpg

 

And the base with main hub.  It has bearings top and bottom and the fork mounting attaches to it.

 

67925zZ.jpg

 

It mounts to the fork assembly with 4 screws (you'll see later) and doesn't rotate with reference to the fork assembly, so the dents have NO impact on function.



#43 deSitter

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Posted 03 July 2017 - 09:21 AM

Good job!

 

-drl



#44 Geo31

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Posted 03 July 2017 - 09:38 AM

OK, longer post here.  Here are the components and assembly of the drive and fork base...

 

First the main ring that everything attaches to:

 

kJdgALw.jpg

 

You can see the spring attached in the wrong place.  You also see the underside of the slo-mo gear with the recess that fits onto the main ring.

 

Next are the pieces that attached the RA SC:

 

k2pVEPk.jpg

 

The SC goes onto the main ring.  Then the spring goes on top of the SC.  Then the slo-mo gear goes on top of that.  Extra points if you have 3 hands.  It would make assembly easier because you have to hold the slo-mo gear in place against the pressure of the spring (which I "enhanced" with some small bends).  While holding it all together, you have to thread some socket head cap screws up through the main ring, into the slo-mo gear.  The spring provides pressure against the SC to hold it in place once you set the SC to the initial coordinates.

 

Next is all this assembled:

 

6e1EUD0.jpg

 

Now you can see the underside of the main ring with the SC assembly completed:

 

y1N8izR.jpg

 

The gear simply slips over the main ring.  It's a really snug fit.  Excellent machining.  Because it's a snug fit, you have to align the bolt holes up very precisely.  You can see how I used a flashlight to align them.  I also found out the threads were 8-32, so I used some extra 8-32 bolts to ensure the alignment was correct enough to allow it all to bolt together.

 

qfDBKH4.jpg

 

Here is everything attached to the main ring:

 

E2qBlMM.jpg

 

And finally, the main ring attached to the hub:

 

4hHELco.jpg

 

The main ring simply sets upon the hub in a machined recess.  The gold colored bit is the clutch and is simply metal on metal, although there is a nylon screw for tension adjustment.  The four screws you see on the clutch are the ones that were really loose and two fell out, allowing the fork assembly to crash into the worm, damaging the RA SC.  I chased the threads with a tap and used 1" instead of the factory 7/8" machine screws with a little reversible thread lock.  Should be good to go for years now.

 

The four bolts actually bolt into the fork assembly piece.  When this is done, it all slides over the RA shaft (as illustrated in one of the earlier photos).  It's held in place with a washer and machine screw.  Put the cap over the screw and bolt the forks on and you're done (at least one fork must be bolted to the OTA or you won't be able to get the OTA on).

 

Here are the socket head cap screws I mentioned.  I just need to get longer ones (the original hex heads are back in place for now).

 

QZLvRC4.jpg


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#45 NMBob

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Posted 03 July 2017 - 10:07 AM

Wow! And despite my best efforts! :)

 

That's really nice. I've never seen the inside the base of one of those before. Interesting differences. For being mass produced they ARE pretty well built and easy to work on (and repair!) if you can remember where the springs go. Sorry about that, again! That RA dial looks great!

 

I really like the counter-weight bar. I bought the Optik one and the weight is 1kg. I thought that would be too light, but it's working out to be pretty good for everything. So 2 to 2-1/2# is a pretty good starting point. These fork mounts are tough to get balanced in all directions. I've found you just have to keep checking it if you are jumping around the sky a lot.

 

That's perfect!

 

Bob



#46 Joe Cepleur

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Posted 03 July 2017 - 12:46 PM

Well done!

"Mass produced," yes; but, didn't Ed Byers himself machine the worms and RA drive gears?

#47 Geo31

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Posted 03 July 2017 - 01:43 PM

Well done!

"Mass produced," yes; but, didn't Ed Byers himself machine the worms and RA drive gears?

He may or may not have machined them himself, but they were engineered by him and produced by his company to his standard.

 

Oh and thanks for the kind words.



#48 Joe Cepleur

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Posted 04 July 2017 - 07:46 AM

Celestron's genius, of course, was that its telescopes *were* mass produced. They must have known their limits, in outsourcing the worms to Byers. Amazing that Byers was so famous that it would be a marketing coup to call this mount a "Byers drive." Perhaps the marketing came first, with Celestron knowing that their scopes mounted on "Buyers drives" would sell? Anyway, great to see yours resurrected. Most of us will never have a Boller and Chivens of our own, so antique Celestrons will remain the bread-and-butter of this branch of the hobby, with Byers drives the choice of the choice.

#49 deSitter

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Posted 04 July 2017 - 12:25 PM

Celestron's genius, of course, was that its telescopes *were* mass produced. They must have known their limits, in outsourcing the worms to Byers. Amazing that Byers was so famous that it would be a marketing coup to call this mount a "Byers drive." Perhaps the marketing came first, with Celestron knowing that their scopes mounted on "Buyers drives" would sell? Anyway, great to see yours resurrected. Most of us will never have a Boller and Chivens of our own, so antique Celestrons will remain the bread-and-butter of this branch of the hobby, with Byers drives the choice of the choice.

Back in the day, imaging was done by hand-guided open-shutter single exposures on a camera or plate.Periodic error correction was obtained by buying a super precise drive that didn't have much PE to begin with! It's hard to remember how primitive it was.

 

-drl


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#50 Brian Risley

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Posted 04 July 2017 - 10:17 PM

Back in the day, imaging was done by hand-guided open-shutter single exposures on a camera or plate.Periodic error correction was obtained by buying a super precise drive that didn't have much PE to begin with! It's hard to remember how primitive it was.
 
-drl

Speak for yourself, I tried imaging with an OT back in the late 70's with the Williams Cold Camera and cut film.  Talk about primitive. 

I also did some work with an OM1 and f5 telecompressor with an OAG.  You prayed that it didn't move too far.

Brian

 


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