Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Easy, Attractive, Non-Destructive Mod For E.S. Twilight I Mount

  • Please log in to reply
27 replies to this topic

#1 JimOfOakCreek

JimOfOakCreek

    Ranger 4

  • *****
  • topic starter
  • Posts: 386
  • Joined: 07 Jul 2010
  • Loc: Wisconsin

Posted 30 June 2018 - 07:52 PM

I liked the features of the Twilight I, especially the slow motion controls. But I did not like the vibration I got when using it. A firm tap at the eyepiece took 4+ seconds to damp out the vibes. I use it with the arm reclined because it's the most convenient configuration. Unfortunately, this is the most vibration prone configuration.

 

Well, I came up with a mod that is easy and effective. I used 6mm Baltic Birch to create a web to brace the gap in the altitude arm. This something the manufacturer should have done! 

 

I cut two pieces, one to brace inside of the altitude-arm and one for outside. The dimension of the inside brace is  2-3/4" X 2-7/16". The 2-3/4" dimension is a bit too long and will have to be sanded back a hair. The inside brace must be cut so that it press fits firmly inside the web of the arm. This is important. The easiest way to do this is to cut the piece to 2-3/4" X 2-7/16". Then sand the 2-3/4" dimension back a bit until it press-fits with a firm snap into the inside web. You do this by trial and error.

 

The outside piece is less critical. The dimension of that piece is 3-1/8" X 2-7/16". It will line up perfectly with the outside edges of the arm.The fasteners are three stainless steel #10 X 1" bolts, nuts washers. Some varnish and white paint made the pieces look decent.

 

After the mod a firm tap at the eyepiece damps in 2+ seconds. A light tap in less than a second. Vibrations while focusing are greatly reduced as well.

 

Take a look at the photos for a better understanding of what was done.

 

ModWedgefit.jpg

 

ModsPaintedPieces.jpg

 

Modsinsideweb.jpg

 

ModStell.jpg


Edited by JimOfOakCreek, 30 June 2018 - 08:04 PM.

  • Lewis Cason, Jaimo!, CeleNoptic and 9 others like this

#2 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 8088
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 01 July 2018 - 04:17 PM

One of the things I am going to try changing for this mount is removing the weather vane barbell piece that screws onto the shaft that connects to the tray.  That thing is in the way of eyepieces whether I put it on top or on the bottom, so it needs to go.  I have some plastic star shaped hand knobs with nut inserts on the way...hopefully they will fit, thread pitch was not listed but they were the right metric size.

 

One of the other things I want to do to address stability is to hang some weight off that same shaft.  I am thinking about ordering a narrow lead cylinder weight of several pounds, and sticking a threaded insert in it so that I can screw it onto the shaft.  I don't know if it will have much impact on vibration, but at least it would move the center of mass lower and more toward center when the arm is in recline position.

 

I would like to see ES redesign the hole pattern in the arm (or base) so that a 45 or even 60 degree position was possible.  The 30 degree angle is excessive and adds extra distance in the horizontal.  I believe that the tendency to vibrate like a spring is something approximating the square of this distance--but I am not a mechanical engineer and this in not my bailiwick.  Of course this is only the impact of this distance alone, exclusive of other factors.  Still that suggests a 60 degree arm setting would be far more stable. 

 

VSP's help with this mount.  Another thing that helps is shorter slow motion cables.  I have borrowed one of the shorter ones off a CG4 and use it in place of the longest one. 


  • JimOfOakCreek likes this

#3 JimOfOakCreek

JimOfOakCreek

    Ranger 4

  • *****
  • topic starter
  • Posts: 386
  • Joined: 07 Jul 2010
  • Loc: Wisconsin

Posted 02 July 2018 - 06:29 PM

One of the things I am going to try changing for this mount is removing the weather vane barbell piece that screws onto the shaft that connects to the tray.  That thing is in the way of eyepieces whether I put it on top or on the bottom, so it needs to go.  I have some plastic star shaped hand knobs with nut inserts on the way...hopefully they will fit, thread pitch was not listed but they were the right metric size.

 

One of the other things I want to do to address stability is to hang some weight off that same shaft.  I am thinking about ordering a narrow lead cylinder weight of several pounds, and sticking a threaded insert in it so that I can screw it onto the shaft.  I don't know if it will have much impact on vibration, but at least it would move the center of mass lower and more toward center when the arm is in recline position.

 

I would like to see ES redesign the hole pattern in the arm (or base) so that a 45 or even 60 degree position was possible.  The 30 degree angle is excessive and adds extra distance in the horizontal.  I believe that the tendency to vibrate like a spring is something approximating the square of this distance--but I am not a mechanical engineer and this in not my bailiwick.  Of course this is only the impact of this distance alone, exclusive of other factors.  Still that suggests a 60 degree arm setting would be far more stable. 

 

VSP's help with this mount.  Another thing that helps is shorter slow motion cables.  I have borrowed one of the shorter ones off a CG4 and use it in place of the longest one. 

 

My opinion is that the main weak point of this mount is the gap in the altitude arm. The modification I made helps reinforce that arm. It suppresses the twisting moment due to torque. It also reinforces the arm to resist the weight of the telescope. The two pieces of Baltic Birch are a design known as a Flitch Plate.

 

I re-constructed that modification a second time. This time I used 12mm Baltic Birch instead of 6mm. The results are excellent.


  • Jon Isaacs likes this

#4 JimOfOakCreek

JimOfOakCreek

    Ranger 4

  • *****
  • topic starter
  • Posts: 386
  • Joined: 07 Jul 2010
  • Loc: Wisconsin

Posted 03 July 2018 - 08:37 AM

I was able to view Jupiter with my Vixen 2.4mm HR and Stellarvue SV102A for a 300X result. I was able to track the planet using the slow mo controls. The mount was pleasantly stable. The oscillation of the long cable knob had no effect on the image. A finger tap caused crazy wild vibration but it damped out in 2+ seconds. 

 

This modification works. I recommend 12mm Baltic Birch. I used SS 6m x 40mm socket button bolts. A coat of varnish hardens the wood. A coat of white paint makes it look good. Strongly recommended if you own this mount.


Edited by JimOfOakCreek, 03 July 2018 - 10:20 AM.

  • CeleNoptic and SteveFour86 like this

#5 Steve Haverl

Steve Haverl

    Vostok 1

  • *****
  • Posts: 101
  • Joined: 16 Mar 2018

Posted 07 July 2018 - 11:41 AM

Regarding redbetters comment about hanging a weight and custom ordering a lead cylinder:

I used an 8 pound sledgehammer head fitted w a cross bolt and large washers. I then suspended it by two 12” solid rubber bungee cords. The setup had a significant damping effect on an exos 1 mount and cost very little. Source the sledge at Harbor Freight.



#6 JimOfOakCreek

JimOfOakCreek

    Ranger 4

  • *****
  • topic starter
  • Posts: 386
  • Joined: 07 Jul 2010
  • Loc: Wisconsin

Posted 07 July 2018 - 05:39 PM

I am not a big fan of suspending heavy weights. I find it unnecessary.



#7 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 8088
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 10 July 2018 - 02:40 AM

I received a pair of handles today for the main tripod shaft, they are M12 female threaded, star shaped knobs:  link.  Approximately $8 shipped from China.  Works just as expected since they are nearly the same as those on the main tripod shaft of the CG4.  The one substantial difference is that these have a longer neck, so that doesn't leave much in the way of exposed threads if I want to add a weight onto the shaft below--might have to swap the handles to do that. 

 

Anyway, the removal/replacement of the barbell allows insertion of 2" and 1.25" eyepieces without interference on top or bottom.   


  • JimOfOakCreek likes this

#8 SteveFour86

SteveFour86

    Ranger 4

  • *****
  • Posts: 337
  • Joined: 14 Dec 2009
  • Loc: Bay City, OR

Posted 18 August 2018 - 12:01 PM

I was able to view Jupiter with my Vixen 2.4mm HR and Stellarvue SV102A for a 300X result. I was able to track the planet using the slow mo controls. The mount was pleasantly stable. The oscillation of the long cable knob had no effect on the image. A finger tap caused crazy wild vibration but it damped out in 2+ seconds. 

 

This modification works. I recommend 12mm Baltic Birch. I used SS 6m x 40mm socket button bolts. A coat of varnish hardens the wood. A coat of white paint makes it look good. Strongly recommended if you own this mount.

Do you have pics of the updated version?  I have this mount and want to put a 6" Mak on it.  It appears your mod is the easy to go.



#9 JimOfOakCreek

JimOfOakCreek

    Ranger 4

  • *****
  • topic starter
  • Posts: 386
  • Joined: 07 Jul 2010
  • Loc: Wisconsin

Posted 18 August 2018 - 04:56 PM

Do you have pics of the updated version?  I have this mount and want to put a 6" Mak on it.  It appears your mod is the easy to go.

 

The upadated version is identacle, exact same dimension. The blocks are are 12mm thick (6mm thicker), the bolts are 6mm D x 40mm long.

 

Peace


  • SteveFour86 likes this

#10 SteveFour86

SteveFour86

    Ranger 4

  • *****
  • Posts: 337
  • Joined: 14 Dec 2009
  • Loc: Bay City, OR

Posted 19 August 2018 - 10:22 AM

Thanks man.  :-)



#11 trurl

trurl

    Hubble

  • *****
  • Posts: 15774
  • Joined: 10 Jul 2017
  • Loc: North Carolina

Posted 19 August 2018 - 10:34 AM

One of the things I am going to try changing for this mount is removing the weather vane barbell piece that screws onto the shaft that connects to the tray.  

That piece is intended to be a wrench that helps with tightening and loosening the mount to the tripod.  When screwed down against the bottom nut on the shaft, it can be used to loosen the mount. When screwed up against the knurled knob/nut it can be used to tighten the mount. When not needed it can be left screwed most of the way to the bottom of the shaft out of the way. The knurled knob/nut is used by itself to hold the spreader tray in position.

 

At least, that is what I do and it seems to make the most sense. Since there are no instructions I have found, and various images have it in all sorts of places, it is confusing.


Edited by trurl, 19 August 2018 - 10:37 AM.

  • Allanbarth1 likes this

#12 Allanbarth1

Allanbarth1

    Skylab

  • -----
  • Posts: 4011
  • Joined: 29 Apr 2016
  • Loc: Central New Jersey

Posted 07 November 2018 - 12:24 PM

That piece is intended to be a wrench that helps with tightening and loosening the mount to the tripod.  When screwed down against the bottom nut on the shaft, it can be used to loosen the mount. When screwed up against the knurled knob/nut it can be used to tighten the mount. When not needed it can be left screwed most of the way to the bottom of the shaft out of the way. The knurled knob/nut is used by itself to hold the spreader tray in position.

 

At least, that is what I do and it seems to make the most sense. Since there are no instructions I have found, and various images have it in all sorts of places, it is confusing.

I do the same with the spinning barbell thing. It makes for easy work of tightening and disassembling when storing the head and tripod. It also makes a good place for to loop the lanyard of my red light so the flashlight is always in the same place  I don't need to search in the dark for where I put the flashlight down last. 

 

Other than that I can't see any logical purpose for the barbell. I do like that with it and the supplied allen wrench I need no other tools for the mount. Nice and easy. 

 

I did add a ADM v-series saddle I had stored away. It was for a project that went in a different direction so now there was no home fo it. I have this saddle.  The spacing for the saddle holes are 2in on center and the Twilight 1 mount spacing is a bit different. I don't remember if it was a tad wider or narrower. All I did to the ADM saddle was to carefully file one of the holes into a 1/2 inch long channel as wide. Like what's on this dovetail bar. Then put the saddle on the drill press and countersunk the recess for the bolt head. Touched up with a file and some black paint, good to go. It bolted up good and tight, nice and straight to the TW1. I really like how easily in the dark I can mount and remove my scopes now with the longer clamping area and the two long knobs. Plus no marking of the dovetail bar from the clamp screws. 

 

I don't know for certain, but it does seem to dampen vibrations a bit quicker now. I didn't time the damping time before the swap but having twice the clamping area and a much firmer positive grip on the dovetail bar it makes sense to me if it did help a little bit. If it did help its a bonus.

 

The reason for even doing this in the first place was I remembered I had the brand new ADM saddle somewhere and no use for it. That's when the light bulb went on in my mind. After seeing it was so close to fitting as it was, I knew it would be a rather easy mod to make work. So I went ahead with it. I knew the ADM would clamp the dovetail more securely and evenly than the stock clamp the TW1 came with. The ADM will not mark up the dovetail bar and it has twice the clamping area. Not to mention, ADM makes quality, nice sturdy products. 

 

If anyone who owns a TW1 and has a extra unused dovetail clamp like this of similar, give it a shot. In my opinion it's easy and worth while. No modification to the mount at all so it can be put back at any time. Just a file and a countersink bit with some patience to file a nice straight channel. If one had access to a milling machine even easier. I would think with an x,y table for a drill press and a good sharp milling tool bit it could (maybe) be done also. 


Edited by Allanbarth1, 07 November 2018 - 12:52 PM.


#13 photoracer18

photoracer18

    Mercury-Atlas

  • *****
  • Posts: 2873
  • Joined: 02 Sep 2013
  • Loc: Martinsburg, WV

Posted 07 November 2018 - 03:49 PM

I am not a big fan of suspending heavy weights. I find it unnecessary.

its an old photography trick and it does work.
  • PatrickVt likes this

#14 erin

erin

    Viking 1

  • *****
  • Posts: 571
  • Joined: 27 Jan 2018
  • Loc: MA

Posted 09 January 2019 - 11:05 AM

Hi all,

 

I just wanted to share my DIY first (and triumph!). I am confident this will help my c102 gt to not shake while focusing. I did everything the way Jim did, but I added a couple pieces of wood and made the front piece longer. I am also awaiting a clamp saddle to have a more secure connection. Best part is all of these mods don't permanently change the mount.

 

But enough chit chat. Let's get to the pics:

Attached Thumbnails

  • EST1.gif
  • EST2.gif
  • EST3.gif

  • vtornado and Allanbarth1 like this

#15 erin

erin

    Viking 1

  • *****
  • Posts: 571
  • Joined: 27 Jan 2018
  • Loc: MA

Posted 09 January 2019 - 11:06 AM

Thanks for sharing this idea, Jim! And for the tips. waytogo.gif



#16 JimOfOakCreek

JimOfOakCreek

    Ranger 4

  • *****
  • topic starter
  • Posts: 386
  • Joined: 07 Jul 2010
  • Loc: Wisconsin

Posted 09 January 2019 - 11:28 AM

Thanks for sharing this idea, Jim! And for the tips. waytogo.gif

Has the mod improved the vibration damping for you?

 

jim


  • erin likes this

#17 erin

erin

    Viking 1

  • *****
  • Posts: 571
  • Joined: 27 Jan 2018
  • Loc: MA

Posted 09 January 2019 - 11:40 AM

I will know when I get a chance to get the scope out. Will post results.

 

I did use it with the original front piece and it was effective. Still some vibration with focus at high mag, but then I was set up on my ground level deck. 



#18 Steve Haverl

Steve Haverl

    Vostok 1

  • *****
  • Posts: 101
  • Joined: 16 Mar 2018

Posted 09 January 2019 - 12:06 PM

I’m pondering a variant of this mod that uses 1/8” thick aluminum bar stock for the two opposing plates instead of the PW. Anyone thried this approach?

 

thanks


  • Cali likes this

#19 erin

erin

    Viking 1

  • *****
  • Posts: 571
  • Joined: 27 Jan 2018
  • Loc: MA

Posted 13 January 2019 - 11:01 PM

I wish I could help you out Steve. I used the 12mm Baltic birch. 

 

Finally got it out on a breeze-less night and on the grass to do some high mag viewing. The mod works like a charm! Still some vibration when focusing with the 102 GT, but dampens in 1-2 seconds. I think it was taking 5-6 before with that particular scope. It was bad enough that by the time I found focus and the object settled, it was out of view. My shorter scopes didn’t have that much vibration. Maybe now they won’t have any fingerscrossed.gif

 

It was well worth the effort smile.gif



#20 Allanbarth1

Allanbarth1

    Skylab

  • -----
  • Posts: 4011
  • Joined: 29 Apr 2016
  • Loc: Central New Jersey

Posted 14 January 2019 - 09:26 AM

Great to hear. I've been thinking of doing something similar. So good to now know multiple folks that have had success with it. 


  • erin likes this

#21 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1878
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 17 February 2019 - 09:23 AM

This is a great thread!  My scope and mount will be here Wednesday and Im getting the birch wood piece today so I can do this mod right away.  So happy - I really didnt want to spend $500++ bucks on a heavier mount.  Now, I can use the TW1 and it'll be rock solid.  Once I get some decent weather here in upstate, NY Ill post back but I suspect it'll be good. 

 

You guys ROCK!  bow.gif


  • Allanbarth1 and erin like this

#22 erin

erin

    Viking 1

  • *****
  • Posts: 571
  • Joined: 27 Jan 2018
  • Loc: MA

Posted 17 February 2019 - 10:08 AM

Glad it’s helpful! I feel the same way. waytogo.gif

 

If you ever want to upgrade the saddle from the screws to a more secure clamp, there’s this:

 

https://www.amazon.c...ope mount&psc=1

 

 This one is $60 from US sellers and ships faster. I got the same thing on eBay for half that and it shipped right from China. No issues and it took a little over a week. Worth the savings, but either route, it is a sweet upgrade!

 

Looking forward to your report!


Edited by erin, 17 February 2019 - 10:09 AM.

  • Mr. Mike and Allanbarth1 like this

#23 Mr. Mike

Mr. Mike

    Surveyor 1

  • *****
  • Posts: 1878
  • Joined: 08 Nov 2005
  • Loc: Churchville, NY

Posted 17 February 2019 - 12:29 PM

Glad it’s helpful! I feel the same way. waytogo.gif

 

If you ever want to upgrade the saddle from the screws to a more secure clamp, there’s this:

 

https://www.amazon.c...ope mount&psc=1

 

 This one is $60 from US sellers and ships faster. I got the same thing on eBay for half that and it shipped right from China. No issues and it took a little over a week. Worth the savings, but either route, it is a sweet upgrade!

 

Looking forward to your report!

Cool - that looks like anither nice upgrade.  Let me see how i make out with the extra bracing and go from there.  Im lazy and cheap..... Ill do the minimum required to make it work! :D


  • erin likes this

#24 erin

erin

    Viking 1

  • *****
  • Posts: 571
  • Joined: 27 Jan 2018
  • Loc: MA

Posted 17 February 2019 - 01:26 PM

lol.gif 

Fair enough.


 



#25 mandopickr

mandopickr

    Explorer 1

  • -----
  • Posts: 87
  • Joined: 27 Feb 2009
  • Loc: South Carolina

Posted 19 February 2019 - 10:51 PM

Thanks for this thread, and thanks to Jim and others for their efforts. I really like my TW I up to about 70x, using my ES AR127, or my 102ED as a grab and go with slow motion controls. Above that magnification, I do have to be careful to keep the damping times down. Part of that effort is to use the barbell to make sure the mount is as tight as it can be on the tripod. I also want to try the larger tripod from my TW II to see if that also helps, but I believe most of the issue is coming from the arm and using a refractor.

 

On my first opportunity I plan to add the blocks to the arm. If I can get any improvement on damping times with the 102ED at 100x, I will consider the efforts a huge success.


Edited by mandopickr, 20 February 2019 - 05:23 PM.



CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics