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Building 10Micron mount models

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#651 SimonIRE

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Posted 18 December 2020 - 12:37 PM

I stand corrected. Tak does make rings. Tracking down those now.

When you find them will you post here please?

There are some very cool silver ones made by a mysterious independent Japanese vendor (begins with K...Kitec or something like that. These looked very solid when in saw them). I have Ron’s Moonlite rings on my FSQ. They are very tight - they tighten on both sides.
.

Edited by SimonIRE, 18 December 2020 - 12:38 PM.

 

#652 mccomiskey

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Posted 18 December 2020 - 12:45 PM

These are they.  The rings close differently than in the photos - they close like the Moonlites.

 

https://www.takahash...lder-125ws.html


 

#653 C8er

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Posted 18 December 2020 - 12:57 PM

I also run my cables, in a cable tube, off the rear of OTA, and get consistent 2.8 to 3 arcsec models with a rigid APM 140mm refractor, with 53 point models.
 

#654 EFT

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Posted 18 December 2020 - 12:58 PM

Greg's recommendations are good.  However, I would recommend increasing your settling times to at least 5 seconds.  Better over-long than under.  Exposure times are completely dependant on equipment and seeing conditions.  You have to find the point where the plate solves are not having any problem (except occasional points) and you are good.  If you get a point that doesn't solve, then rerun those points only after your first run is complete.

 

I completely agree with running the cable off the back of the OTA and not down the counterweight shaft.  A flexible cable (or cables) will work very well off the back.  You just need to make sure they are long enough to reach all positions.  I have never had a snag this way.  The problem that I see with running them down the counterweight shaft is that are coming off a point on the mount furthest away from the axes of rotation and as a result they will always place some pressure on that point, even if it is not much cable.  A cable running off the back end of the dovetail is far closer to the axes so it results in far less pressure.  

 

The tripod extension does make some sense.  In a cheap tripod, this position would be terrible due to all of the flexure that occurs.  In a tripod like the Aries (or Centaurus), the extension does not result in the same amount of flexure while it does increase the circle of the legs which provides greater stability overall, particularly with a "lighter" system.  It's another one of those differences that you might not think about if you come from a mount and tripod that are not of this quality.

 

Getting rings for the Takahashi is a real pain.  Only a few scopes have TAK rings available.  Finding aftermarket rings that fit the TAK scopes (or just about any scope for that matter) is difficult.  I looked around for some rings for my new 60Q and could find only those from PrimaLuceLab and a company on AliExpress.  I got the PrimaLuceLab rings but at the weight of this system I'm not particularly concerned.  Someone needs to produce a material that is flexible, won't compress, can be easily cut, can be glued to something, and won't mark up the scope to solve the felt problem.  I don't like the clamshells since, because they are designed to mount directly onto a TAK mount, they are not really designed for dovetail mounting.  There are some good aftermarket remedies for that, but it is still a use they were not designed for.  Also, attaching an upper dovetail is far more difficult to do with stability on the top of the clamshell.  


 

#655 mccomiskey

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Posted 18 December 2020 - 01:04 PM

I also run my cables, in a cable tube, off the rear of OTA, and get consistent 2.8 to 3 arcsec models with a rigid APM 140mm refractor, with 53 point models.

What is a cable tube?  Would you mind posting a link to one?


 

#656 yzhzhang

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Posted 18 December 2020 - 01:15 PM

I also run my cables, in a cable tube, off the rear of OTA, and get consistent 2.8 to 3 arcsec models with a rigid APM 140mm refractor, with 53 point models.

 

 

I completely agree with running the cable off the back of the OTA and not down the counterweight shaft.  A flexible cable (or cables) will work very well off the back.  You just need to make sure they are long enough to reach all positions.  I have never had a snag this way.  The problem that I see with running them down the counterweight shaft is that are coming off a point on the mount furthest away from the axes of rotation and as a result they will always place some pressure on that point, even if it is not much cable.  A cable running off the back end of the dovetail is far closer to the axes so it results in far less pressure.  

Can you guys share some pics of the cabling you are describing? I have been following Per's layout in which he did anchor the cable to the CW shaft. If there is a better way of doing this I'll love to learn.

 

Thanks,

Yizhou


 

#657 Greg F

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Posted 18 December 2020 - 01:43 PM

Greg,

 

Extremely helpful and informative.  Thanks much.  I am jealous of the FSQ130.  By the time I started to focus (pun intended) on astrophotography, those were no longer available.  Any chance you would be willing to share a photo of your setup?  I am always interested in seeing how other people do things, as I continue to search for best practices and solutions to adopt.

 

A few questions/comments:

  • I don't believe there are Tak rings for the FSQ106.  I think that they just make clamshell, which I assume would be inferior for these purposes.  I do have a set of Moonlite rings, which I believe are well regarded for this scope, so can move to those.
  • Balance - in its current position, the OTA is balance on both axis to 0.1%.  I had read somewhere that it was better to leave a slight imbalance (which never made sense to me for a mount with absolute encoders, but equally, I had assumed 0.1% out was not material, so why not).  I will get it to 0.0% on my next try.
  • I assume the rationale for putting the rings over the center of the dovetail is that the ring/dovetail interface is where the flexure is being initiated, and by positioning them at the center, this is minimized?  If so, does adding weight on to the front of the dovetail recreate this issue?  Are there other reasons to seek out this positioning?
  • In the FWIW category, I, like you, use 2x2 binning, 2 second settle, 4 second exposures with the Lum filter and a 60% crop for model building.  I have wondered whether an effective 18micron pixel with a sampling of 7" to a side might be part of the issue with my higher RMSs, and whether i shouldn't move to 1x1 binning.  Thoughts on that front?
  • I will give the cable off the back approach a try, too.

 

Many thanks again. 

 

Unfortunately, I will be away from my scope for the next two weeks, but this will give me much to work on in January.

It looks like in another post you were able to find the Tak rings.  My rings came with a small connecting bar which limited me where I could put them. With the rings all the way to the rear up against the Moonlite and putting the scope as far forward as possible and at the same time keeping the rings centered dead above the mount, this will make you back end heavy. Using a shorter dovetail and attaching weight to the front as close as possible to the mount but not obstructing the movement I'm sure does add some flexure but having the scope rings directly over the mount is much better than having the weight of the scope at the end of a dovetail that is not supported under the ring by the mount connection. I am headed to the observatory today, I will take a short video circling the mount and post it to better see the setup.

 

I have always used 2x2 binning for building the model, I have tried 1x1 and see no improvement. The 2x2 is faster and more sensitive thus more accurately finds the center of stars, to my understanding.

 

I'm sure the 0.1% balance is good enough, I'm just a stickler and with a permanent setup I had the time to get it to 0.0% . My understanding about having it heavy on one side is for lesser mounts with a lot of back lash, for the 10Micron balance it as perfectly as possible.

 

One other thing I forgot to mention. At the beginning of each night of imaging I use the 10Micron time Sync program, once synced I turn it off. I have used it and kept it on, either is fine but you definitely should sync each night.


 

#658 Greg F

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Posted 18 December 2020 - 01:45 PM

These are they.  The rings close differently than in the photos - they close like the Moonlites.

 

https://www.takahash...lder-125ws.html

These are the rings I use


 

#659 Tonk

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Posted 18 December 2020 - 03:35 PM

Parallax make scope rings for Tak telescopes

http://www.parallaxi....com/rings.html

However these are the ones I had trouble with the thick felt - until I applied my chemists training to the problem wink.gif - after my mod the felt was rigid and molded to the scope and then the 10M mount models where back to expected numbers


Edited by Tonk, 18 December 2020 - 03:37 PM.

 

#660 Tonk

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Posted 18 December 2020 - 03:39 PM

How to cable up ...

9rtWZammzVw4_620x0_kWXURFLk.jpg


Edited by Tonk, 18 December 2020 - 03:42 PM.

 

#661 Tonk

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Posted 18 December 2020 - 03:47 PM

Also Google "braided sleeving"  for cable management - you put your cable bundle into one of these to keep it all together

Example here - https://www.amazon.c.../dp/B071JH14WZ/


Edited by Tonk, 18 December 2020 - 03:52 PM.

 

#662 mccomiskey

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Posted 18 December 2020 - 04:03 PM

Also Google "braided sleeving"  for cable management - you put your cable bundle into one of these to keep it all together

Example here - https://www.amazon.c.../dp/B071JH14WZ/

Much appreciated.  That is a suitably impressive rig you he set up.  I assume that is your unit in Spain?  The braided sleeving I am familiar with (just momentarily confused by the term "cable tube").  I went through a decabling exercise 6 months ago, and now I have literally only one cable coming off the OTA, which is the power cable that connects to the Eagle3 (networking is handled by connecting the mount to my home network by ethernet cable and the Eagle3 to the home network by wifi, all other connections are short power/USB cables between the Eagle and the relevant device).


 

#663 SimonIRE

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Posted 18 December 2020 - 04:04 PM

I have a set of parallax rings for my FSQ but never used them. To be honest, I thought the finish was pretty poor.
 

#664 Tonk

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Posted 18 December 2020 - 04:28 PM

To be honest, I thought the finish was pretty poor.


You wait - try stacking scopes with them - the top scope leans. The outer faces are not parallel :(. You have to machine them to get that
 

#665 Greg F

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Posted 18 December 2020 - 04:58 PM

Along with the Takahashi rings this is the dovetail I use with the rings.  https://www.admacces...arge-takahashi/  It is only 12.25" long and very stout, it allows me to attach the weights to the bottom If I need to.


 

#666 Greg F

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Posted 18 December 2020 - 05:14 PM

My rings are actually not over center completely as I stated earlier like I thought, the front ring is out a little, no choice, as close as I could get it. As far as cables coming down, (braided tube is the right term I guess) I have the eagle power cable and ethernet cable. I have 2 cables running from my MGPBox -1 to turn the power on the 10Micron on and off remotely and the other running into the 10Micron computer and 1 USB cable running from the eagle to the 10Micron computer -USB to RS232. One of these cables I am sure is not needed but it works so I keep them, all. They are all in the cable sleeve so they act as one either way.


Edited by Greg F, 18 December 2020 - 10:18 PM.

 

#667 Tonk

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Posted 18 December 2020 - 05:49 PM

I assume that is your unit in Spain?


back in UK - waiting for Covid to go away so it can be shipped to Chile

I have 1 USB cable running from my eagle to the 10Micron computer.


As the 10Micron computer does not have USB sockets - I'm assuming this is a USB to RS232 serial converter cable?
 

#668 Greg F

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Posted 18 December 2020 - 06:02 PM

back in UK - waiting for Covid to go away so it can be shipped to Chile
 

 



As the 10Micron computer does not have USB sockets - I'm assuming this is a USB to RS232 serial converter cable?

 

Yes, USB to RS232 that is correct


Edited by Greg F, 18 December 2020 - 10:08 PM.

 

#669 Whichwayisnorth

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Posted 19 December 2020 - 01:16 PM

Can you guys share some pics of the cabling you are describing? I have been following Per's layout in which he did anchor the cable to the CW shaft. If there is a better way of doing this I'll love to learn.

 

Thanks,

Yizhou

I also follow Per's layout.  Never had a single issue.  Except I do remove the front elevation knob because the cable loops up near it and it could potentially grab on to it.   Going out the back you have the weight of the cable pulling down on it and the cables can snag on the computer box or rub across the DEC cable etc.  Just too much going on back there for me to trust it.  


 

#670 Tonk

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Posted 19 December 2020 - 03:14 PM

Going out the back you have the weight of the cable pulling down on it and the cables can snag on the computer box or rub across the DEC cable etc.  Just too much going on back there for me to trust it.


None of this happens - my cable is light (only 3 in harness). Put the computer box elsewhere - mines cable tied higher on side ... and hence DEC cable goes nowhere near the mobile cable

Edited by Tonk, 19 December 2020 - 07:31 PM.

 

#671 jeffweiss2131

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Posted 19 December 2020 - 03:45 PM

This setup works for me with no cable issues. I understand this is a simple setup but it might help with your cabling plan. Wire ties help but also snag on things. I will move toward a cable cover soon. I change the scope out often so I save each cable harness separately.

 

https://u.pcloud.lin...nSyEQTfEyS7rL87

 

Another setup that works well for me:

 

https://u.pcloud.lin...xSSbWhmBfFPKPDX


Edited by jeffweiss2131, 19 December 2020 - 04:01 PM.

 

#672 Whichwayisnorth

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Posted 19 December 2020 - 04:08 PM

This setup works for me with no cable issues. I understand this is a simple setup but it might help with your cabling plan. Wire ties help but also snag on things. I will move toward a cable cover soon. I change the scope out often so I save each cable harness separately.

 

https://u.pcloud.lin...nSyEQTfEyS7rL87

 

Another setup that works well for me:

 

https://u.pcloud.lin...xSSbWhmBfFPKPDX

Looks good to me.


 

#673 RazvanUnderStars

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Posted 20 December 2020 - 12:45 PM

Regarding the earlier (pg 6) discussion on the mount having the tracking rate set to Custom after alignment, see this message in a different thread, George Hilios found bugs in the ASCOM driver that explain them.


 

#674 C8er

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Posted 20 December 2020 - 05:33 PM

What is a cable tube?  Would you mind posting a link to one?

Mine is like like the braided one in Tonk's link


 

#675 C8er

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Posted 20 December 2020 - 05:48 PM

Can you guys share some pics of the cabling you are describing? I have been following Per's layout in which he did anchor the cable to the CW shaft. If there is a better way of doing this I'll love to learn.

 

Thanks,

Yizhou

This my cabling setup off rear of OTA. Cables in a braided cable tube (like in Tonk's link) running from main body of focuser (but sometimes from rear of plate on top of OTA) down to the 10M laser pointer holder on side of lower part of mount, with a large enough loop that it doesn't get significantly pulled/stretched at any sky pointing position. I get 2.8 to 3 arcsec RMS models consistently with this setup, 53 points, with a 140mm frac, or around 8" with a C11 Edge HD so it seems to work ok.

 

https://photos.app.g...hh1RXnjZvNBoqD9


 


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