152 replies to this topic

[PETER DREW]

Anyone else noticed how much more interesting these threads about the "old" telescopes are than those of the latest "whizz" models?

[rolo]

At the time i used one there was no Paracorr and Nags were still pretty rare blare.

[clamchip]

strictly curious< could you weigh just the OTA,  what you would pick up to put on the mount. You'll need a bathroom scale, those usually hit the 300lb capability though it shouldn't be that much.

I'd like to know the OTA weight too, I'll see what I can do.

The Meade Starfinder 16 inch which is pretty much the same telescope, OTA weighs 100 lbs.

And then add the 40lb and 25lb counterweights to the operating weight.

The DS-16 mounting is a tuff little unit to handle all that weight.

The key to the mount's success is those beautiful big thrust surfaces on both axis.

 

Robert

Edited by clamchip, 25 October 2018 - 10:10 AM.

[tim53]

I'd like to know the OTA weight too, I'll see what I can do.

The Meade Starfinder 16 inch which is pretty much the same telescope, OTA weighs 100 lbs.

And then add the 40lb and 25lb counterweights to the operating weight.

The DS-16 mounting is a tuff little unit to handle all that weight.

The key to the mount's success is those beautiful big thrust surfaces on both axis.

 

Robert

I'd like to take some credit for those thrust bearings, but the truth is that Diebel and Ezra were already probably thinking the same thing I was, which was "if you're going to use Cave castings to make a new mount, don't just grind off the Astrola name.  Incorporate thrust bearings to the axes like Optical Craftsmen did.  Hanging the weight of the telescope on the cantilevered shafts is Cave's bottleneck."  Or words to that effect, Parker, Meade Instruments, ~1979.

 

-Tim.

[Geo31]

What amazes me is that, nobody ever used a Torrington bearing, at least on the premium mounts.  If I were to make a heavy duty ATM mount today, I’d definitely use them.

[Richard Whalen]

The only experience I have with a DS16 was using Ed Boutwells up on the hill in the small obervatory at the Prude Ranch. Was not very impressive, lots of scatter and seagulls. Was worth the views though listening to Ed tell one story after another. Never used a DS10.

[DS-16A]

So, I had a little extra time today and decided to weigh my DS16A to compare with other who have weighed or will weigh theirs. I hope it all makes sense.

 

1) Optical tube with mirror cell and finder scope installed, no eyepiece installed, no guide scope installed: 86 lbs.
2) Pedestal only, no "head", wheels, or leveling screws: 21.5 lbs.
3) "Head" only, no counterweights installed, includes declination tangent arm and clock drive: 67 lbs.
4) Mirror and cell only: 36 lbs.
5) Counterweights, small: 23.5 lbs.
                               Large: 39 lbs.
6) Pedestal only, with wheels and leveling screws: 30 lbs.
7) Wheels (3): Total: 6 lbs.
8) Leveling screws (3): Total: 2.5 lbs.
9) Meade Model 300 (3.1”) guide scope: 6 lbs.

Total of entire telescope setup: 251.5 lbs.

[clamchip]

Your weights are great thanks.

 

Because I have ants in my pants I'm going to mount the OTA on my Star-Liner 2 inch shaft mount.

I think its up to the job, and that way I can use the telescope. My DS-16 mounting needs to be taken

apart and lubed, and I just finished doing this to my Star-Liner mount.

 

I just measured the DS-16 mirror and it's 16-1/4 inches in diameter, quite a bit bigger than 16 inches.

I measured it because I'm going to cutout a paper disk to find the center of the mirror for a notebook

reinforcement ring, and then I can use a barlowed laser to help get the collimation very close, finish

the collimation with Polaris since it doesn't move.

 

I was reading in the manual you can use a Meade #918A diagonal prism in the eyepiece-holder of

the DS-16.

The prism permits more comfortable observations of objects in the southern or western skies.

Good to know because you cannot rotate the tube.

 

Robert

 

 

 

Edited by clamchip, 25 October 2018 - 06:05 PM.

[CHASLX200]

Just thinking about lifting that OTA would scare me away.  It just so hard to grab and hold with such a big OD.

[CHASLX200]

Your weights are great thanks.

 

Because I have ants in my pants I'm going to mount the OTA on my Star-Liner 2 inch shaft mount.

I think its up to the job, and that way I can use the telescope. My DS-16 mounting needs to be taken

apart and lubed, and I just finished doing this to my Star-Liner mount.

 

I just measured the DS-16 mirror and it's 16-1/4 inches in diameter, quite a bit bigger than 16 inches.

I measured it because I'm going to cutout a paper disk to find the center of the mirror for a notebook

reinforcement ring, and then I can use a barlowed laser to help get the collimation very close, finish

the collimation with Polaris since it doesn't move.

 

I was reading in the manual you can use a Meade #918A diagonal prism in the eyepiece-holder of

the DS-16.

The prism permits more comfortable observations of objects in the southern or western skies.

Good to know because you cannot rotate the tube.

 

Robert

I had the same 2" Starliner mount and it would be a better choice.

[clamchip]

Just thinking about lifting that OTA would scare me away.  It just so hard to grab and hold with such a big OD.

It definitely scares me.

I would think it nearly impossible to get the bolts in the saddle holes and the wing nuts on.

The guy I bought it from would do it himself by placing a dog leash around the tube to give

himself a hand hold, and placing the other hand on the bottom edge of the tube. Install the

mirror after the tube is attached to the saddle.

I'm too chicken to do it, and I'm thinking of doing what I've seen amateurs do with C-14's.

You place the OTA on something, a small table etc., vertical or horizontal, and then you

bring the mount saddle up to the telescope tube and 'dock' with it. Seems like a good idea.

 

Robert

[CHASLX200]

It was just a dumb idea from the get go to thread two ring studs in tiny saddle holes. As i was saying in my Cave thread.  A simple V notch would be much more easy to slide the ring studs into the holes.  I could draw a pic and post if i need to.

[DS-16A]

It definitely scares me.

I would think it nearly impossible to get the bolts in the saddle holes and the wing nuts on.

The guy I bought it from would do it himself by placing a dog leash around the tube to give

himself a hand hold, and placing the other hand on the bottom edge of the tube. Install the

mirror after the tube is attached to the saddle.

I'm too chicken to do it, and I'm thinking of doing what I've seen amateurs do with C-14's.

You place the OTA on something, a small table etc., vertical or horizontal, and then you

bring the mount saddle up to the telescope tube and 'dock' with it. Seems like a good idea.

 

Robert

There was a guy, I believe on this site, that showed a picture of his DS16 in his yard, showing how he mounted the tube to the pedestal. Exactly the way you said. Made a fixture level with the tube when it was in the horizontal position and slid it into place. Looked for the post, but can't seem to find it. He also had a chain wrapped around the existing counterweights for added weight. I'll keep looking to try and find it. 

[precaud]

There was a guy, I believe on this site, that showed a picture of his DS16 in his yard, showing how he mounted the tube to the pedestal. Exactly the way you said. Made a fixture level with the tube when it was in the horizontal position and slid it into place. Looked for the post, but can't seem to find it. He also had a chain wrapped around the existing counterweights for added weight. I'll keep looking to try and find it. 

That was moi. I hand-trucked the OTA out to the pad, flipped it over length-wise onto a padded aluminum work platform that was the same height as the bottom of the rings when horizontal (counterweight shaft supported by a notched 2x4 to keep it level), and then rolled it in place. Easy-peasy.

Glad you liked the chain counterweight 

 

 

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[CHASLX200]

Your weights are great thanks.

 

Because I have ants in my pants I'm going to mount the OTA on my Star-Liner 2 inch shaft mount.

I think its up to the job, and that way I can use the telescope. My DS-16 mounting needs to be taken

apart and lubed, and I just finished doing this to my Star-Liner mount.

 

I just measured the DS-16 mirror and it's 16-1/4 inches in diameter, quite a bit bigger than 16 inches.

I measured it because I'm going to cutout a paper disk to find the center of the mirror for a notebook

reinforcement ring, and then I can use a barlowed laser to help get the collimation very close, finish

the collimation with Polaris since it doesn't move.

 

I was reading in the manual you can use a Meade #918A diagonal prism in the eyepiece-holder of

the DS-16.

The prism permits more comfortable observations of objects in the southern or western skies.

Good to know because you cannot rotate the tube.

 

Robert

 

post-50896-14073921389609_thumb.jpg

Best way to find the center is to spin it around and use a marker until it becomes a point. If you are off it become a circle once on center it becomes a point.

Edited by CHASLX200, 26 October 2018 - 05:10 AM.

[CHASLX200]

That was moi. I hand-trucked the OTA out to the pad, flipped it over length-wise onto a padded aluminum work platform that was the same height as the bottom of the rings when horizontal (counterweight shaft supported by a notched 2x4 to keep it level), and then rolled it in place. Easy-peasy.

Glad you liked the chain counterweight 

Clamp rings are much more easy to mount the tube in.

Edited by CHASLX200, 26 October 2018 - 05:12 AM.

[Geo31]

Best way to find the center is to spin it around and use a marker until it becomes a point. If you are off it become a circle once on center it becomes a point.

Uh, NO.  OMG.

 

Best way is exactly what Robert is doing.

 

I couldn't let this go.  I'd hate for some newbie to read this and think it acceptable.

[rolo]

Agreed! Robert's template is a much better idea. I keep a Catseye template handy...

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Edited by rolo, 26 October 2018 - 07:06 AM.

[precaud]

Clamp rings are much more easy to mount the tube in.

 

Yes, but the same technique works without them. I discovered it before installing the rings.

[tim53]

It definitely scares me.

I would think it nearly impossible to get the bolts in the saddle holes and the wing nuts on.

The guy I bought it from would do it himself by placing a dog leash around the tube to give

himself a hand hold, and placing the other hand on the bottom edge of the tube. Install the

mirror after the tube is attached to the saddle.

I'm too chicken to do it, and I'm thinking of doing what I've seen amateurs do with C-14's.

You place the OTA on something, a small table etc., vertical or horizontal, and then you

bring the mount saddle up to the telescope tube and 'dock' with it. Seems like a good idea.

 

Robert

I've done that even with my 12.5" Cassegrain by putting the OTA on top of a rolling cabinet.  When you roll the mount up to it, leave the counterweight off until you have the tube attached, then add the counterweight.

 

Easy as cake.

[tim53]

Or with the 12.5" Transportable Observatory:

 

 

Add counterweight and you're done!

[CHASLX200]

Uh, NO.  OMG.

 

Best way is exactly what Robert is doing.

 

I couldn't let this go.  I'd hate for some newbie to read this and think it acceptable.

Done IT with 50+ mirrors.  Just check for dead center , spin it on a lazy susan and BOOM done.  Clean up with Q tip chip and install. It is not like that part of the mirror gets light anyways.

Edited by CHASLX200, 27 October 2018 - 05:33 AM.

[rolo]

What amazes me is that, nobody ever used a Torrington bearing, at least on the premium mounts.  If I were to make a heavy duty ATM mount today, I’d definitely use them.

How about heavy duty needle bearings like Criterion used on their deluxe mounts?

[tim53]

Done IT with 50+ mirrors.  Just check for dead center , spin it on a lazy susan and BOOM done.  Clean up with Q tip chip and install. It is not like that part of the mirror gets light anyways.

I have never added a center spot to any of my mirrors.  Once or twice, the coater did, and some of the meade's I've owned had them.  I've never found them all that useful.

 

-Tim.

[tim53]

How about heavy duty needle bearings like Criterion used on their deluxe mounts?

Or how about tapered roller bearings?