Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Mounts

Pages: 1 | 2 | (show all)
Patrick
Postmaster
*****

Reged: 05/16/03

Loc: Franklin, Ohio
Improving Polar Alignment Adjuster Mechanics
      #5906225 - 06/06/13 03:01 PM

I have a CGEM mount which has a very good altitude adjustment knob on it. I have zero issues with precisely placing the altitude where I want it.

However, the azimuth adjustment mechanism is a real pain in the behind. To make adjustments in azimuth I first have to loosen the main center bolt slightly and then fight the two opposing screws back and forth...back and forth...to align the azimuth. It's sometimes a struggle because of overshooting the mark and then having to back off one screw and retighten the other one. When I do get it where I want it, then I have to tighten the center bolt which can throw off the alignment in both directions. So, I have to make sure not to loosen the center bolt very much which makes adjustment in the azimuth that much more difficult.

There has to be a better way!

Does anyone have any tricks or techniques that would make it easier to adjust the azimuth alignment on a CGEM?

Thanks,

Patrick


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hilmi
Post Laureate
*****

Reged: 03/07/10

Loc: Muscat, Sultanate of Oman
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5906315 - 06/06/13 03:53 PM

I had a similar problem back when I used to use a wedge with my LX200r. Then I purchased a third party upgrade with less backlash and it made all the difference.

Post Extras: Print Post   Remind Me!   Notify Moderator  
starbob1
Pooh-Bah


Reged: 03/11/07

Loc: IN
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Hilmi]
      #5906373 - 06/06/13 04:23 PM

Yes that is a pain. I also use a cgem. But I sprayed my bolts with WD40 to help some with adjusting. I also just slighty loosen the center bolt'just enough to move the mount. Just part of it I guess. Bob

Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Improving Polar Alignment Adjuster Mechanics new [Re: starbob1]
      #5906376 - 06/06/13 04:26 PM

With both the CGEM and the Atlas, loosening the bolt that holds the head to the tripod when you are polar aligning is just a fact of life. Once it's tightened down, you'll find you can still adjust azimuth a little bit if it's been thrown off by the tightening.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Footbag
Post Laureate
*****

Reged: 04/13/09

Loc: Scranton, PA
Re: Improving Polar Alignment Adjuster Mechanics new [Re: rmollise]
      #5906402 - 06/06/13 04:44 PM

With my CPC, I made the final small adjustment with the wedge tightened down. It makes the small movements easier.

Post Extras: Print Post   Remind Me!   Notify Moderator  
WesC
Carpal Tunnel
*****

Reged: 02/06/13

Loc: La Crescenta, CA
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Footbag]
      #5906412 - 06/06/13 04:48 PM

Yeah I was dealing with this frustration last night. And having an unlighted polar scope doesn't help.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mert
Post Laureate
*****

Reged: 08/31/05

Loc: Spain, Pamplona
Re: Improving Polar Alignment Adjuster Mechanics new [Re: WesC]
      #5906501 - 06/06/13 05:46 PM

Adjusting Azimuth on my EQ6 used to be a pain, after
which I took some sanding paper and sanded slightly
both surfaces that rub against each other.
Then applying a bit of white grease ( little bit ) and
now I can adjust even with the head fully locked down
onto the tripod, still moving very smooth!
Maybe an idea ???


Post Extras: Print Post   Remind Me!   Notify Moderator  
gustavo_sanchez
sage


Reged: 12/30/10

Loc: Puerto Rico, US
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Mert]
      #5906524 - 06/06/13 05:54 PM

I have this same problem with my Sirius EQ-G when mounted in a CGEM tripod. However, if I use the SVP pier accessory between the two, then I don't have any problems at all. The mount head - pier top interface is much smoother than the mount head - tripod hub interface.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Patrick
Postmaster
*****

Reged: 05/16/03

Loc: Franklin, Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: gustavo_sanchez]
      #5907062 - 06/06/13 10:43 PM

Quote:

I took some sanding paper and sanded slightly
both surfaces that rub against each other.
Then applying a bit of white grease ( little bit ) and
now I can adjust even with the head fully locked down
onto the tripod, still moving very smooth!




Quote:

The mount head - pier top interface is much smoother than the mount head - tripod hub interface.




Interesting. I think both of you guys are suggesting that the frictional forces between the bottom face of the mount head and the surface it's sitting on (tripod or pier) play a significant role in how easy it is to make azimuth adjustments. I had not considered that, but it certainly makes sense. I'm going to have to take a serious look at those interfaces to see what I can do to reduce the friction. I have a slightly different setup because of my pier plates.

Thanks!

Patrick


Post Extras: Print Post   Remind Me!   Notify Moderator  
rkayakr
sage
*****

Reged: 10/27/10

Loc: Northeast Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5907103 - 06/06/13 11:12 PM

As an alternative to the polish and grease approach I have used the trusty milk carton plastic ring (old dobs secondary adjustment trick) to make a low friction surface to ease azimuth adjustment on several GEMs. I also use molybdenum disulfide dry lube on the adjustment bolt threads and crown the ends for smooth contact.

Post Extras: Print Post   Remind Me!   Notify Moderator  
RTLR 12
Post Laureate
*****

Reged: 12/04/08

Loc: The Great Pacific NorthWest
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5907123 - 06/06/13 11:25 PM

I use UHMW Film tape on top of the tripod. Makes movement very easy even with the center bolt tight.

Stan


Post Extras: Print Post   Remind Me!   Notify Moderator  
Patrick
Postmaster
*****

Reged: 05/16/03

Loc: Franklin, Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: RTLR 12]
      #5907246 - 06/07/13 12:51 AM

Quote:

I use UHMW Film tape on top of the tripod.




That sounds like a good idea.

Patrick


Post Extras: Print Post   Remind Me!   Notify Moderator  
cuivienor
professor emeritus


Reged: 10/07/10

Loc: Tokyo, Japan
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5907382 - 06/07/13 07:02 AM

I put my mount on a sturdy photo tripod with central column (fully retracted). There is always a bit of play in azimuth when the column is slightly unlocked, and I use that play to make the final adjustments.

Post Extras: Print Post   Remind Me!   Notify Moderator  
samm
member


Reged: 06/24/07

Re: Improving Polar Alignment Adjuster Mechanics new [Re: cuivienor]
      #5907391 - 06/07/13 07:17 AM

would this work: putting a cd disk between the top of the tripod and the bottom of the head ?

Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Improving Polar Alignment Adjuster Mechanics new [Re: samm]
      #5907445 - 06/07/13 08:10 AM

Quote:

would this work: putting a cd disk between the top of the tripod and the bottom of the head ?




Might. But a simpler solution, which I used, was to apply a very thin layer of bicycle chain grease. Probably didn't need to, but it does make the azimuth smoother.


Post Extras: Print Post   Remind Me!   Notify Moderator  
lukasik
Carpal Tunnel
*****

Reged: 10/11/05

Loc: Lawrenceville, Georgia
Re: Improving Polar Alignment Adjuster Mechanics new [Re: rmollise]
      #5907582 - 06/07/13 09:37 AM Attachment (24 downloads)

Hi Patrick,

Similar to sugggestions above I used .020" polyester shim stock from McMaster Carr to make a washer between the mount and tripod for my C5 clone. I also made a new knob with a thrust bearing to hold it all together. The addition of the thrust bearing allows the assembly to remain tightly clamped and still have very fine control over azimuth adjustments.

Best Regards,

Bob


Post Extras: Print Post   Remind Me!   Notify Moderator  
lukasik
Carpal Tunnel
*****

Reged: 10/11/05

Loc: Lawrenceville, Georgia
Re: Improving Polar Alignment Adjuster Mechanics new [Re: lukasik]
      #5907584 - 06/07/13 09:37 AM Attachment (19 downloads)

#2

Post Extras: Print Post   Remind Me!   Notify Moderator  
lukasik
Carpal Tunnel
*****

Reged: 10/11/05

Loc: Lawrenceville, Georgia
Re: Improving Polar Alignment Adjuster Mechanics new [Re: lukasik]
      #5907585 - 06/07/13 09:38 AM Attachment (17 downloads)

#3

Post Extras: Print Post   Remind Me!   Notify Moderator  
Patrick
Postmaster
*****

Reged: 05/16/03

Loc: Franklin, Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: lukasik]
      #5907607 - 06/07/13 09:48 AM

Thanks for the pics, Bob! I'm now thinking I may have to do a complete overhaul on the azimuth interface.

As I'm thinking about and researching this, the traditional 'post' with counter acting screws is probably not the best mechanical arrangement.

I came across the Malco 360 Degree Rotating Pier Platel for AP mounts. I wonder if something like that could be adapted to a CGEM.

Patrick


Post Extras: Print Post   Remind Me!   Notify Moderator  
DaveJ
Carpal Tunnel
*****

Reged: 01/07/05

Loc: NE Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5907642 - 06/07/13 10:09 AM

Quote:

Does anyone have any tricks or techniques that would make it easier to adjust the azimuth alignment on a CGEM?




Sure do! Link. A fellow NE Ohio CGEM owner and I got a 1' piece of this stuff each. We cut donuts out and installed. No more azimuth adjustment problems - at all. With the center bolt fully tightened, the azimuth adjustments are now smooth as butter - actually feels like it's on bearings!


Post Extras: Print Post   Remind Me!   Notify Moderator  
EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: Improving Polar Alignment Adjuster Mechanics new [Re: DaveJ]
      #5907719 - 06/07/13 10:53 AM

Lots of possibilities here. Smoothing both surfaces is one, but they need to be smoothed flat which may be difficult and two flat surfaces can "stick" together so lube may be necessary.

Lube by itself is a possibility but only one I would use on a mount that is not going to be removed from the tripod since dirt will get in there and make things worse.

Plastic from a milk jug is cheap and seems to work reasonably well. I have cut thick PTFE bearings for people to put between the mount and tripod and that seems to work very well.

TPI Astro is considering making an adjuster similar to the one they made for the CGE but for the EQ6. Ideally, this should work for the CGEM as well. It will not be cheap, but it will allow for very fine adjustment.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Edmond S.
member


Reged: 07/05/10

Re: Improving Polar Alignment Adjuster Mechanics new [Re: EFT]
      #5908122 - 06/07/13 03:05 PM

I use PTFE sheet between my mount and the home-made wooden pier plate, and add some lithium grease on the azimuth bolt screw. It works pretty well.

Edited by Edmond S. (06/07/13 03:06 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Alph
Carpal Tunnel


Reged: 11/23/06

Loc: Melmac
Re: Improving Polar Alignment Adjuster Mechanics new [Re: DaveJ]
      #5908165 - 06/07/13 03:30 PM

Quote:

Quote:

Does anyone have any tricks or techniques that would make it easier to adjust the azimuth alignment on a CGEM?




Sure do! Link. A fellow NE Ohio CGEM owner and I got a 1' piece of this stuff each. We cut donuts out and installed. No more azimuth adjustment problems - at all. With the center bolt fully tightened, the azimuth adjustments are now smooth as butter - actually feels like it's on bearings!



Have you tried that on the CGE?


Post Extras: Print Post   Remind Me!   Notify Moderator  
DaveJ
Carpal Tunnel
*****

Reged: 01/07/05

Loc: NE Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Alph]
      #5908234 - 06/07/13 04:01 PM

Quote:

Quote:

Quote:

Does anyone have any tricks or techniques that would make it easier to adjust the azimuth alignment on a CGEM?




Sure do! Link. A fellow NE Ohio CGEM owner and I got a 1' piece of this stuff each. We cut donuts out and installed. No more azimuth adjustment problems - at all. With the center bolt fully tightened, the azimuth adjustments are now smooth as butter - actually feels like it's on bearings!



Have you tried that on the CGE?




No, I haven't since the CGE never caused me much grief in AZ adjustments, at least not nearly as much as the CGEM DX. Now you've got me thinking...


Post Extras: Print Post   Remind Me!   Notify Moderator  
EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Alph]
      #5908295 - 06/07/13 04:24 PM

Quote:

Quote:

Quote:

Does anyone have any tricks or techniques that would make it easier to adjust the azimuth alignment on a CGEM?




Sure do! Link. A fellow NE Ohio CGEM owner and I got a 1' piece of this stuff each. We cut donuts out and installed. No more azimuth adjustment problems - at all. With the center bolt fully tightened, the azimuth adjustments are now smooth as butter - actually feels like it's on bearings!



Have you tried that on the CGE?




The CGE uses an internal adjustment mechanism whose problem is the very coarse adjustment mechanism itself as opposed to two painted metal plate rubbing together. No at all the same problem as a CGEM or Atlas mount and cannot be solved in the same manner.


Post Extras: Print Post   Remind Me!   Notify Moderator  
A. Viegas
scholastic sledgehammer
*****

Reged: 03/05/12

Loc: New York City/ CT
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5908363 - 06/07/13 04:54 PM

I would echo the advice for the plastic milk/water jug idea. I bought a 1 gallon 99c water gallon... Used the water to make coffee and water some plants, then proceeded to cut a rough circle, brought it to the CGEM mount head attachment, cut out the center hole and cut a notch for the alignment peg. Then i sprayed it with WD40.

Works like a charm. No need to loosed the attachment bolt, you can keep it tight. Alt-AZ adjustment is easy.

Total cost 99c


Al


Post Extras: Print Post   Remind Me!   Notify Moderator  
Alph
Carpal Tunnel


Reged: 11/23/06

Loc: Melmac
Re: Improving Polar Alignment Adjuster Mechanics new [Re: EFT]
      #5908367 - 06/07/13 04:55 PM

Quote:

The CGE uses an internal adjustment mechanism whose problem is the very coarse adjustment mechanism itself as opposed to two painted metal plate rubbing together. No at all the same problem as a CGEM or Atlas mount and cannot be solved in the same manner.



I think it is a universal problem with all mounts that have azimuth bolts including the AP900/1200. I believe the Paramount MX/ME II mounts are exception. They don’t have azimuth bolts.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Patrick
Postmaster
*****

Reged: 05/16/03

Loc: Franklin, Ohio
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Alph]
      #5918082 - 06/13/13 12:56 AM

Just as a followup...I added a layer of Slick Strips, available at Woodcraft, to the top of my pier plate and that pretty much solved my problem with polar aligning in the azimuth direction. I did not have to loosen the center bolt and I could still move the mount using the two azimuth knobs.
The polar align routine went from a 10 minute ordeal to a 60 second operation.



Thanks for the inputs!

Patrick


Post Extras: Print Post   Remind Me!   Notify Moderator  
WesC
Carpal Tunnel
*****

Reged: 02/06/13

Loc: La Crescenta, CA
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Patrick]
      #5919230 - 06/13/13 05:51 PM

Excellent! Thanks for the link. I'm going to try those too.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Stargazer78
professor emeritus
*****

Reged: 03/05/13

Loc: Susanville California
Re: Improving Polar Alignment Adjuster Mechanics new [Re: WesC]
      #6051446 - 08/28/13 08:23 PM

Where exactly did you install these at? Looks like I am having the same problem.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Stargazer78
professor emeritus
*****

Reged: 03/05/13

Loc: Susanville California
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Stargazer78]
      #6051902 - 08/29/13 03:51 AM

Ok so I made a temp gasket out of a milk jug and it works! Why doesn't these mounts come with a gasket????. I placed a order for those slick strips you guys mentioned. For a $2,000 dollar mount I would of expected better.

Post Extras: Print Post   Remind Me!   Notify Moderator  
orlyandico
Post Laureate
*****

Reged: 08/10/09

Loc: Singapore
Re: Improving Polar Alignment Adjuster Mechanics new [Re: Stargazer78]
      #6051906 - 08/29/13 03:59 AM

One major improvement would be to re-tap the adjustment bolts with a larger-diameter but finer-pitch thread.

I think the existing bolts are M5 or M6 x 1mm.. if re-tapped for M8 x 0.5 you'd immediately get twice the resolution.

Also the bolt handle if it had ridges would be better. for example on the Mach1, the bolt handle has lots of ridges on it, so you get precisely 3 arc-min per ridge. the CGEM just has this cheesy round-ish bolt handle, don't know about the DX. i guess ADM handles would do better here but they only have four lobes - not a lot of resolution.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Stargazer78
professor emeritus
*****

Reged: 03/05/13

Loc: Susanville California
Re: Improving Polar Alignment Adjuster Mechanics new [Re: orlyandico]
      #6051909 - 08/29/13 04:04 AM

Its just sad that of all things a milk jug fixes this issue!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
18 registered and 46 anonymous users are browsing this forum.

Moderator:  Dave M, richard7, bilgebay, iceblaze 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 1192

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics