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Calling all Edmund 8" grey Gem scope info

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#51 apfever

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Posted 19 June 2018 - 05:32 PM

I'm waiting on 1/32" Teflon sheet which should arrive from UT later this week. The rusty recess at the end of the RA shaft didn't have any Teflon bearing in it when I took it apart. The top bearing sheet had a mushed edge and I'll replace that as well. These shafts will get cleaned up when the Teflon arrives and assembled with the needle thrust bearings. The Teflon sheet is all I need to finish final assembly. I used the Teflon washers for temporary assembly work.

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#52 apfever

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Posted 19 June 2018 - 05:45 PM

Assembly is done from the legs up through the RA housing.

Fun with numbers: How many allen bolts in the cap and LAT lever arm?

All the bolts in the pier cap and latitude lever arm, without exception, are 5/16 NC stainless allen bolts. They all appear the same in the pictures. Each picture has multiple bolts not visible, that can be seen in the other picture. The two pictures show ALL bolts in the cap and lever arm. How many bolts are there?
By the way, it's not the stock factory number, ignore the two hex head bolts in the RA housing.

Several of the original set screws were cracked at the hex corners, one fell apart by itself. The set screws were abused, ugly, barbaric, and all in dire need of replacement. I like the new look.

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Edited by apfever, 19 June 2018 - 05:59 PM.

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#53 apfever

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Posted 07 November 2018 - 08:53 PM

I put this together Monday after figuring out this little entry here:

 

https://www.cloudyni...s-for-ra-shaft/

 

I then found two issues. The first is the setting circles, which is a stopping point.  I've looked around the web quite a bit, which pulled up old forgotten pictures I took of this scope too, and I have no idea what Edmund did for the factory installed setting circles. It seems Edmund did not even include circles in many cases, and most pictures didn't show any at all. The installed DEC circle here won't work in this position as the DEC lock is trapped. The circle would have to be much lower. I'd like to know how Edmund held the circles in place. Did they use a stop collar on each side, or just a rubber bushing? A spacer?  

The RA circle goes on the machined area of the RA housing, just under the pointer. I don't know what Edmund used on each side, but there must have been something. The 6" uses a rubber ring on each side but the 8" machined area is 1/2" wide. I can cut rubber rings, made plenty of those to original configurations.  Any identification of original ring installation would be greatly appreciated. The DEC circle is still on the kitchen counter waiting.

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#54 CHASLX200

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Posted 07 November 2018 - 08:57 PM

Best mount i ever had.  Smooth as milk and silk. No darn drives and clutches to add slop.


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#55 apfever

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Posted 07 November 2018 - 09:13 PM

Second issue is that I didn't have a stop collar (shaft collar) to hold the DEC shaft and saddle in place. The entire assembly could fall out during a flip.  I picked up an order from Grainger this afternoon. It's a double split stop collar so no more set screw. I soooooo tired of shaft set screws, even with the proverbial super light rounding and polish. Soooooo tired of set screws. (how tired are you?)  I'm more weary of set screws than a lot of the repetitive daily  dribble blabber in this forum. This one worked great and I'll be getting a few more. The double split allows it to be removed without having to strip the shaft to slide it off. They run about $10 from any source in regular steel compared to about 4 or 5 dollars for a regular cheap solid set screw type, for a 1.5" bore.  I'd like to put one on each side of the setting circle but that does start to add up since I can't just butt up against the shaft holder shown. I could use a sleeve and washer system with a rubber ring on each side. The hole in the circle is already a light push fit. Ebay has some 2 pack and 4 pack double split sets that get down to about $7 or $8 per collar.

 

I have a third needle bearing and race assembly that I bought just for the bottom of the DEC shaft. However, this is almost always not under any load unless you flip in RA. I used an original Teflon washer (white thing) instead and kept the bearing assembly sealed in the box for now. 

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Edited by apfever, 07 November 2018 - 09:17 PM.

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#56 clamchip

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Posted 07 November 2018 - 09:13 PM

I agree.

Does this picture help?

 

post-50896-14074281691136_thumb.jpg


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#57 Garyth64

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Posted 07 November 2018 - 09:35 PM

If the build is similar to the 1" mount, the setting circles may be set between two pieces of rubber o rings.

 

Edmund mount 1.jpg

Edmund mount 2.jpg

 

You may be able to see the black rubber rings.


Edited by Garyth64, 07 November 2018 - 09:36 PM.

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#58 apfever

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Posted 07 November 2018 - 09:40 PM

It's getting a drive. I have an original. I was thinking of doing the drive with a quick release to allow for the show off slip slide magnetic type fluid suspension of the shafts.  I'll be honest. With the needle thrust bearings and a 'dry' Teflon lube, the saddle sits there and spins circles with a flick of one finger. It's enough to look really weird. The assembly as shown is just slightly heavier with torque on the shaft side of the saddle. By turning it sideways and letting it go, the RA shaft swings back and forth with pendulum motion. It's all freaky to watch and feel. Video time but I don't do that stuff. Have to watch that the saddle doesn't hit the pier during play. The needle thrust bearings should have a lube of some kind. They have a numerical flaw that requires some slippage instead of true roll. True ball thrust bearings were too thick. 

The Teflon is attached to the RA shaft and spins in the housing. This allows it to be an easy removal and re install for getting the original setting circle on for a photo.  I won't keep the setting circles on for most purposes as they are too susceptible to damage. Clamp collars play into that.

 

 

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#59 apfever

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Posted 07 November 2018 - 09:57 PM

If the build is similar to the 1" mount, the setting circles may be set between two pieces of rubber o rings.

 

attachicon.gif Edmund mount 1.jpg

attachicon.gif Edmund mount 2.jpg

 

You may be able to see the black rubber rings.

I have the original type rubber for those rings and I've made the flat ring washers many times using a double circle cutter on a drill press. It's a little tricky. I make extras when I do and I'd send you a set if you want. The original rubber is meshed reinforced. I make them a very thin hair larger in outside diameter and they don't cover any print on the circles. The machined width on the 6" mount is about 1/4" and the flat rubber washers are 1/8".  The machined section of the 8" mount is 1/2" which would require two 1/4" rubber washers. I'm just not sure how Edmund did it. I'd like to know what came from the factory even if I decide to not duplicate it exactly. I likely will, then remove and store the system for safe keeping. 

 

Here, go down to post #43

https://www.cloudyni...ge-2?hl= edmund

You can see them installed in post #47


Edited by apfever, 07 November 2018 - 10:05 PM.


#60 apfever

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Posted 07 November 2018 - 10:13 PM

Robert......um...you have a lot of stuff hung on that mount, and it's older than mine by the symmetrical pier cap.  I'll go with the options offered by the offset, but I admire the earlier stuff.applause.gif

 

You have a clamping knob in the DEC housing?  I don't even have a hole for that. Is the housing clamp needed due to the DEC slo mo assembly you have? nnnnnno that assembly (I'm drooling) should lock the shaft.

Are your clamp knobs original? My clamp knobs, with the captive slide rod, are original and the slide rod is stuck with the setting circle against the stop collar.  …….

 

OK,  sheesh I need to read my own post.  

Robert, look at your picture in post #15 as well as the one in post #16. The DEC pointer is very long, and I now remember seeing this before. This puts the original setting circle down far enough to clear the slide rod on the clamp. Also look at that original setting circle with the rubber grommet. I have that grommet installed on my RA circle for safe keeping. My current circles are original Edmund prints but not bored for this particular mount. I knew that because the RA circle is too small to go on the housing. I'm taking a NOW pic of this. This is awesome. I will be modifying the original configuration such that it could still be made original if desired, but I doubt any one would want to. 

 

Here are my current Edmund setting circles. I acquired these because the original ones on the mount were pretty bad.  My DEC circle (top) is a slide fit on the shaft as it and will stay that way. I'll clamp it between two stops with a rubber ring on each side which should hold it solid once set, yet allow easy enough reset.

The RA circle has the right size hole to hold the original dec circle grommet. I'll keep that grommet in the original parts pack. The RA circle needs to be bored to fit on the RA housing shoulder. The only thing I don't know is what Edmund put on each side of the RA circle if anything. Not a huge deal now bit it would be nice to know.  I'll cut some oversized OD rubber washers and back that with some metal ones. My rubber strips for making the 6" mount washers are wide enough to make the 8" mount washers. This will work. 

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Edited by apfever, 07 November 2018 - 10:55 PM.


#61 clamchip

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Posted 07 November 2018 - 11:46 PM

That gadget on the dec shaft is a optional slo-motion unit.

It and the other knob on the dec housing are handy for locking the mount up when

installing or removing the OTA.

My drive is Pacific Instruments and the setting circle is part of the worm gear.

 

Robert



#62 clamchip

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Posted 07 November 2018 - 11:55 PM

Here's something really neat, these circles were optional and go on the machined spots on

the Edmund Extra Heavy Duty, rarer than a albino possum.

 

post-50896-0-61009100-1421544121_thumb.jpg

post-50896-0-00982900-1421543917_thumb.jpg

post-50896-0-97104400-1421544153_thumb.jpg


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