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

Basic tracking mount for a light telescope setup?

mount
  • Please log in to reply
15 replies to this topic

#1 Olhado

Olhado

    Vostok 1

  • -----
  • topic starter
  • Posts: 105
  • Joined: 22 Jun 2005

Posted 05 July 2020 - 09:16 AM

So I am a mostly visual/occasional smartphone AP person, living in bortle 9 skies where convenience is at a premium. I currently have the equipment in my signature below, and honestly, the hand tracking with the M1 mount is “fine”, but not amazing. And I certainly can’t do even short exposures of anything, just video of bright things and one-off shots of others.

So given I want to keep the tripod (weight rating 10kg), and my scope with rings, diagonal, eyepiece, smartphone adapter and smartphone being 9-10 pounds when all is said and done, what would work to just get unguided tracking for basic viewing and smartphone photography with exposures of maybe up to 30 seconds or so? (The ability to take longer exposures would awesome too )

It doesn’t need goto, or wireless connectivity or any of that. I do worry that the tripod may be the “weakest” link in the chain, and I might have been better off getting a slightly larger berlebach with a greater load rating...

#2 Hesiod

Hesiod

    Skylab

  • *****
  • Posts: 4,099
  • Joined: 13 Jan 2013

Posted 05 July 2020 - 09:41 AM

There are few interesting small equatorial mounts, the Skywatcher eq3 (manual, clock drive or 2-axis drive) and Vixen AP being my top pick.

The Eq3 is sold with a tripod (worse than your Report), while you'd need an adapter to mount the AP on the Report, or purchase the optional AP tripod.

Think that Berlebach have a suited tripod too.

 

A bit more extreme option could be the Fornax Lighttrack 2: it can be used with your tripod, has an amazing tracking accuracy but, having been devised as astrophotography platform, has some quirks too (and it is not cheap). The Astrotrac Travel Set may be another worthy optioon but, having been discontinued, have to find one in the aftermarket

I have the Astrotrac Travel Set, which can be seen as a sort of "forefather" of the Lighttrack, and it is my main grab and go mount:

here with a C8 for a bit of Moongazing at 360x (I was using the Berlebach Report tripod: the telescope is not steady as a rock, focusing vibrations dampened in more than 1" but thanks to the tracking is enjoyable for high-power observations)

gallery_215679_8115_97502.jpg

 

Here with the M500 for a deep sky session (the telescope is as heavy as the C8, but being narrower behaves better. Also the travel pier is more rigid than the tripod)

gallery_215679_8115_1297190.jpg

 

Here for Sun observing with a 100/740 refractor (very stable. I used the pier as it is more handy to travel since can put inside it most of the mount)

gallery_215679_8115_6366853.jpg

 

At 540mm I managed to take 120" subs (the "bottleneck" being the polarscope, no the tracking accuracy of the Astrotrac. Beside, I reached my "sky limit" so did not push further with PA).

 

The biggest issue with such a device is that the "declination module" is actually a small altazimuthal head whose design is very critical about balance.


  • eros312 likes this

#3 Olhado

Olhado

    Vostok 1

  • -----
  • topic starter
  • Posts: 105
  • Joined: 22 Jun 2005

Posted 05 July 2020 - 11:09 AM

There are few interesting small equatorial mounts, the Skywatcher eq3 (manual, clock drive or 2-axis drive) and Vixen AP being my top pick.
The Eq3 is sold with a tripod (worse than your Report), while you'd need an adapter to mount the AP on the Report, or purchase the optional AP tripod.
Think that Berlebach have a suited tripod too.

A bit more extreme option could be the Fornax Lighttrack 2: it can be used with your tripod, has an amazing tracking accuracy but, having been devised as astrophotography platform, has some quirks too (and it is not cheap). The Astrotrac Travel Set may be another worthy optioon but, having been discontinued, have to find one in the aftermarket
I have the Astrotrac Travel Set, which can be seen as a sort of "forefather" of the Lighttrack, and it is my main grab and go mount:
here with a C8 for a bit of Moongazing at 360x (I was using the Berlebach Report tripod: the telescope is not steady as a rock, focusing vibrations dampened in more than 1" but thanks to the tracking is enjoyable for high-power observations)
gallery_215679_8115_97502.jpg

Here with the M500 for a deep sky session (the telescope is as heavy as the C8, but being narrower behaves better. Also the travel pier is more rigid than the tripod)
gallery_215679_8115_1297190.jpg

Here for Sun observing with a 100/740 refractor (very stable. I used the pier as it is more handy to travel since can put inside it most of the mount)
gallery_215679_8115_6366853.jpg

At 540mm I managed to take 120" subs (the "bottleneck" being the polarscope, no the tracking accuracy of the Astrotrac. Beside, I reached my "sky limit" so did not push further with PA).

The biggest issue with such a device is that the "declination module" is actually a small altazimuthal head whose design is very critical about balance.


So the clock drive would be basic tracking in one axis?

What are the quirks with the fornax? That and the astrotrac look basically ideal for me (quality, light, can support my scope, not too heavy for my tripod), but the prices, once you include the wedge and telescope adapters seems like it might tip me over the load limit for the tripod, especially once a counter weight is included, which I believe is necessary for a telescope setup on those mounts?

#4 makeitso

makeitso

    Messenger

  • *****
  • Posts: 461
  • Joined: 31 Jan 2016
  • Loc: SoCal

Posted 05 July 2020 - 11:23 AM

I just have to put this out there, I’m very happy with this setup and its way inexpensive.

 

I recently got a celestron cg4. It starts out as an eq mount. I easily converted it to an az. It can be used either way now without much trouble. It is solid with my AT102ED. I has slomo controls and there’s a motor drive kit that can be added for use in eq mode. I suppose you could use the motors to guide by hand in az mode.

 

It can be had new for under $300, the drives can be had for under $150. It took me all of 45 minutes to do the mod. These come up all the time used in the classified section.

 

Some pics with my AT102ED on board. The last is a picture of the result.

 

Jack

 

 

Attached Thumbnails

  • EFC86801-9113-4628-931A-F97C5C22CEBA.jpeg
  • 0757FB06-3EC6-4CA3-A611-07DD617538FF.jpeg
  • 8D356D42-8038-40E3-99A4-A042923B5B05.jpeg


#5 Olhado

Olhado

    Vostok 1

  • -----
  • topic starter
  • Posts: 105
  • Joined: 22 Jun 2005

Posted 05 July 2020 - 11:32 AM

I just have to put this out there, I’m very happy with this setup and its way inexpensive.

I recently got a celestron cg4. It starts out as an eq mount. I easily converted it to an az. It can be used either way now without much trouble. It is solid with my AT102ED. I has slomo controls and there’s a motor drive kit that can be added for use in eq mode. I suppose you could use the motors to guide by hand in az mode.

It can be had new for under $300, the drives can be had for under $150. It took me all of 45 minutes to do the mod. These come up all the time used in the classified section.

Some pics with my AT102ED on board. The last is a picture of the result.

Jack


Interesting! Are the mod instructions available online? How heavy is the mount? Can it easily be swapped to a different tripod?
  • makeitso likes this

#6 Jond105

Jond105

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 5,479
  • Joined: 19 Feb 2018
  • Loc: Detroit

Posted 05 July 2020 - 11:34 AM

I love my motorized CG4. It handles my iPhone XR and celestron NexYZ adapter on 100 degree eyepieces no problem. I see no reason to ever get rid of this mount ever. 

Attached Thumbnails

  • 79BD9AB3-C1C6-45B3-97D0-B002F07812AC.jpeg

  • eros312, Terra Nova and makeitso like this

#7 Jond105

Jond105

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 5,479
  • Joined: 19 Feb 2018
  • Loc: Detroit

Posted 05 July 2020 - 11:34 AM

It works out wonderfully. I do Facebook live events all time using this mount. 

Attached Thumbnails

  • 3097E590-1909-4630-A95A-3A148D676555.jpeg

  • makeitso likes this

#8 makeitso

makeitso

    Messenger

  • *****
  • Posts: 461
  • Joined: 31 Jan 2016
  • Loc: SoCal

Posted 05 July 2020 - 11:56 AM

Interesting! Are the mod instructions available online? How heavy is the mount? Can it easily be swapped to a different tripod?

It’s really easy to do if you have a dremel or even a file would work.

 

First, I removed these parts. The long bolt is the one for the south side (for those of us in the northern hemisphere).

 

C902054D-6FF6-4893-9119-0A82784703C6.jpeg

Then, I ground off a portion of the mount blocking the altitude adjustment  tab, preventing it from going vertical. Cut a piece of aluminum channel, drilled a few holes in the aluminum channel and finished.

 

0BBA5789-E0CF-41E9-8DC4-46D689E83F60.jpeg


Edited by makeitso, 05 July 2020 - 12:00 PM.


#9 Hesiod

Hesiod

    Skylab

  • *****
  • Posts: 4,099
  • Joined: 13 Jan 2013

Posted 05 July 2020 - 11:59 AM

Yes, it tracks just in RA.

The first and most obvious quirk is that, due to the shape, you have a blind spot: as can see in the pictures, I have assembled the tracker at different angles.

Second, it tracks for just two hours, then you have to "rewind" the drive and start again.

Third, it lacks slow motion controls or setting circles

Fourth, as already posted, it is extremely sensible to balance to have smooth manual movements.

Fifth, while it could use standard counterweights with 20mm bore, doing so may be really risky because there is not enough clearance to allow the CWs to slew past the tracker unless are very small (the white one in the second picture is a Vixen 0.5kg CW they sell for the Polarie tracker)

These are the Astrotrac's quirks the Lighttrack basically "inherited"; the Astrotrac has another nastiness of its own in the use of 6 smallish Allen screws to be assembled.

 

As for the weight, the fully assembled head is around 4 kg, the stock CWs make for 2 kg ( 1.3+0.7); I use the C8 (itself around 6kg) but need the extra 0.5 CW, so overall load atop the Report is around 11kg: it is not a "perfect" setup, but I rate as usable.

The Astrotrac Travel Set is no longer available, but is not uncommon in second-hand market and probably could secure a good deal.

The Travel Set is quite heavy (the pier is around 6kg) but very convenient to carry resembling a poster tube, as long as do not mind losing 10 minutes assembling and disassembling it every time:

gallery_215679_8115_79883.jpg

 

This, and its Fornax friend, were designed to be used with photographic tripods, and with great attention to portability (are/were sold for travel deep sky AP);  however, as far as I remember Berlebach offered their tripod with interfaces for the most common mounts.

 

Smaller equatorial mounts such as the Eq3 I suggested in my first post (it is basically the same as Celestron Cg4, but fitted to a smaller, lighter and weaker tripod) need a different interface to link to the tripod but, as far as I remember, Berlebach offered their tripods ready for the use with all the most common models: it would not help the current case, but can improve the portability (and stability) of the mount by replacing the stock tripod with an appropriate one from the German firm; in any case both the Eq3 and CG4 are sold with a tripod included so may take your time to evaluate the performances; the eq3 can be equipped with single axis drive or 2-axes drive (there are two version of the latter, the more expensive "deluxe" has a red control box and features an autoguiding interface).

Vixen AP is rather pricey, does not have the sheer accuracy of Fornax/Astrotrac devices but is designed as a full-fledged astronomical mount (and a very clever one too: had not already the Astrotrac, and placed the order for the Astrotrac360, that would be my first choice as travel mount); it can be equipped with only the RA or both RA and DEC drives, the HC being the same.



#10 makeitso

makeitso

    Messenger

  • *****
  • Posts: 461
  • Joined: 31 Jan 2016
  • Loc: SoCal

Posted 05 July 2020 - 12:05 PM

I’m not Sure how much the cg4 weighs, but I can carry the whole thing out as pictured above in one trip, mount, tripod and OTA. 
 

Jack



#11 Jond105

Jond105

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 5,479
  • Joined: 19 Feb 2018
  • Loc: Detroit

Posted 05 July 2020 - 12:15 PM

Also with the CG4 you may not need to replace the 1.75” stainless legs. I’ve never had a problem with them. Just throw some vibration pads under if you feel the need to. I do on the concrete and deck. Been doing grass observing done lately and haven’t really needed them. 



#12 Olhado

Olhado

    Vostok 1

  • -----
  • topic starter
  • Posts: 105
  • Joined: 22 Jun 2005

Posted 10 July 2020 - 09:12 AM

Thanks for the feedback, everyone! I at least know where the ballpark is now lol.gif

 

Do people think upgrading the tripod would be a worthwhile plan at some point?



#13 Olhado

Olhado

    Vostok 1

  • -----
  • topic starter
  • Posts: 105
  • Joined: 22 Jun 2005

Posted 10 July 2020 - 09:50 AM

Oh, one other thing! What power supplies are recommended? I was looking at the Celestron PowerTank Lithium, and in the FAQ on the Celestron site there is a note that the battery shuts down at a draw of 250mh. The fornax site says the draw for the lightrack is 150mm, which seems like a problem?



#14 Hesiod

Hesiod

    Skylab

  • *****
  • Posts: 4,099
  • Joined: 13 Jan 2013

Posted 10 July 2020 - 11:19 AM

What you prefer or your conscience dictates..."clock-driven" mounts have really low need for power and could even do with AAs (10 if rechargeable, 8 if single use).

Any 12V Lithium battery will last a lot of time (from days to months between recharging sessions).

The Astrotrac draws around 200mAh and, like all this kind of devices, does not have "surges" because the tracking speed is always the same (by the way, it sound strange that the Celestron powertank shuts down at absorption higher than 250mA, because goto mounts needs much higher values, even 2-3A. Also, I use a simple and inexpensive "emergency phone charger" with the Polarie and even this can yield 2A).

 

I have a Tracer 14A 12V battery which I bough for a goto eq mount, but try to use with the Astrotrac as well and that ensures weeks of "power" between chargings; since it has started to deteriorate after several years am thinking of getting with a smaller one for the Astrotrac (think that the smallest should be around 4A. Those batteries are handier to recharge than 10 AA).

While I prefer to avoid AAs, those are for sure handy on travels as can be found everywhere in the world and have not issues with boarding security checks (especially because do not have to fly them, as could purchase the set after landing and dispatch them before boarding). "Heavy duty" ones are the better as last quite a long and IME have a more stable voltage, which is important for the Astrotrac being it quite whimsical about that parameter (if voltage is too low it folds back and refuse to open again): by summer, and with a well balanced load, a set of those can last even 8-10 hours.



#15 Olhado

Olhado

    Vostok 1

  • -----
  • topic starter
  • Posts: 105
  • Joined: 22 Jun 2005

Posted 11 July 2020 - 04:06 PM

Ah, I was confusing. The PowerTank shuts down at draws of 250mA OR LOWER, not higher.



#16 Hesiod

Hesiod

    Skylab

  • *****
  • Posts: 4,099
  • Joined: 13 Jan 2013

Posted 12 July 2020 - 09:38 AM

That makes more sense. The PowerTank looks devised to work with GoTo mounts, whose draws are higher, but could give headaches with too low-consumption devices.

 

As for the tripod, if opt for a mount like the CG4/Eq3 will get also a new tripod, and in my opinion the best course of action would be to carefully evaluate the tripod's performances.

If not pleased may try to fix it, or replace.

If opt for the Vixen AP guess you have to purchase its tripod as well, and that it is perfectly suited to the job.

If, at last, opt for the tracker, my suggestion is to try it atop your current model first: you could be surprised by the results.


  • Olhado likes this


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





Also tagged with one or more of these keywords: mount



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics