Skymax 180, my impressions and findings

[nfotis]

Since I saw Synta raising prices across the board, I decided to get one from a German dealer who had this in stock and hadn't raised the prices (yet).

I have an old abused HEQ5 mount (which I bought used), and I reckoned that it should be able to handle the Skymax 180 more easier than the C9.25 I bought from a member of the forum, since it's more than 2 kg lighter for the OTA.

 

The good things I noticed:

- Finish looks good, the package survived the trip to Athens without much exterior damage.

- The size of the OTA is easier to handle than a C9.25

- The view through it looks quite sharp on land targets (I attach some photos from my Canon 80D mounted on the visual back). The antennas are approximately 6.5 km from me, while the house is approximately 3.5 km away.

 

The bad things I noticed:

- Focus is hard to achieve manually when shooting photos (too narrow a range for optimal focus, and the HEQ5 is not stable enough). At 2700+ mm focal distance, the image is quite sensitive to vibrations as I touch the OTA/focuser.

- The 9mm eyepiece doesn't seem useful - I would prefer Synta including a better version than this. Heck, even my SVBONY zoom eyepiece is sharper and offers a better eye relief.

- The adapter from 2" to 1.25" has only one screw, and it's really bad. Very hard to secure stuff from it, better to throw it away and buy a new one.

 

Things I would like to do in order to get better results before resorting to a pricey higher category mount:

- Get a good 2" to 1.25" adapter (preferably with a pressure ring)

- Find an electronic focuser, in order to get accurate focus without touching the OTA. I think that I would like to get a focuser with a handheld control, maybe in combination with a Crayford type focuser?

- Get vibration reducing pads for the HEQ5 tripod, in order to reduce the jelly-like view (here's a video showcasing it):  https://www.youtube.com/watch?v=LKlq80kJ-QA

 

My and my nephew used the OTA visually with a 2" Bresser 25mm eyepiece on the Moon, the Synta 25mm 1.25" eyepiece and the SVBONY zoom 7-21mm. The moon was lots of fun, as long as you didn't jerk the OTA too much trying to get perfect focus. Tried it also seeing the double star Albireo, it was ludicrously easy to separate them even in light polluted Athens. The two-inch eyepiece was quite pleasant to use (bought it used from another member), I think that I should get one more wide in order to contain the complete moon disk? (not a big deal, to be honest)

N.F.

 

 

[nfotis]

The land target photos were shot as a test after my tests on the Moon etc yesterday, trying to get something out of this all-nighter.

Forgot to add that I liked the supplied finder. Quite bright and useful when trying to hunt a target. I haven't understood how to rotate the eyepiece, it seems fixed orientation, but I may have missed something.

 

N.F.

 

[Mr Spock]

The first thing I bought for my new 250mm Dob was a 2" to 1.25" compression adaptor as the supplied 1.25" fitting is pants.

[GazOC]

A Crayford adds a fair bit of weight to the setup. I found it useful when I was imaging with my 180 Mak/ HEQ5 setup but not visually

[nfotis]

1 hour ago, GazOC said:

A Crayford adds a fair bit of weight to the setup. I found it useful when I was imaging with my 180 Mak/ HEQ5 setup but not visually

One idea I read is bolting a motor on the second place for mounting extra accessories, then driving the focus screw via a toothed belt. Will see about it (in fact, I have one TS Crayford focuser somewhere, but it seems that's of a large size, probably SCT - will have to take some measurements)

https://www.teleskop-express.de/shop/product_info.php/info/p3947_TS-Optics-2--MONORAIL-Dual-Speed-Focuser-for-SC-Telescopes---SC-Thread.html

(I think that's the one - will check if it fits the Skymax 180)

If it works, I think that a simple motor and a remote control like this should work?

https://www.teleskop-express.de/shop/product_info.php/info/p7908_TS-Optics-Focus-Motor-for-many-2--focusers---for-motor-driven-focusing.html

 

N.F.

 

 

[nfotis]

On 23/05/2021 at 05:44, nfotis said:

One idea I read is bolting a motor on the second place for mounting extra accessories, then driving the focus screw via a toothed belt. Will see about it (in fact, I have one TS Crayford focuser somewhere, but it seems that's of a large size, probably SCT - will have to take some measurements)

https://www.teleskop-express.de/shop/product_info.php/info/p3947_TS-Optics-2--MONORAIL-Dual-Speed-Focuser-for-SC-Telescopes---SC-Thread.html

(I think that's the one - will check if it fits the Skymax 180)

If it works, I think that a simple motor and a remote control like this should work?

https://www.teleskop-express.de/shop/product_info.php/info/p7908_TS-Optics-Focus-Motor-for-many-2--focusers---for-motor-driven-focusing.html

 

N.F.

 

 

 

Got an email from TS claiming that this motor won't work with the focuser I mentioned (hard to believe, it's a typical GSO Crayford focuser)

There was a suggestion to get this adapter and a ZWO EAF: https://www.teleskop-express.de/shop/product_info.php/info/p13058_Wega-mounting-kit-for-ZWO-EAF-motor-focus-on-Monorail-N2-focuser.html

 

Maybe this one should work? I would prefer a simple low cost DC motor myself.

https://www.teleskop-express.de/shop/product_info.php/info/p6385_Skywatcher-AccuFocus-for-Dual-Speed-Crayford-Focuser.html

The manual of Orion Accufocus seems to imply that's suitable for my needs, but I would like to verify before ordering.

https://www.telescope.com/assets/product_files/instructions/29246_06-11.pdf

N.F.

 

 

Edited May 26, 2021 by nfotis

[Robindonne]

I think these simple dc motors work on (almost) every screwed on crayford or r&p focuser where the focusknob can be detached and show a spindle ánd when there is a sort of flat surface between the 2 knob sides.

 I remember having owned such a crayford focuser once where the spindle wasnt that solid for some reason. It was a single speed gso and also didnt have that flat surface between the knobs.
 

A bit like the left side on this picture:

As far as I remember the motor couldn’t be attached to this one. 
 

I have seen some solution where they connect a autofocuser via a belt to the standard focusknob.   
 

All options using the standard focusknob will show some mirror movement. If thats no problem for you than go for that option.  

Edited May 26, 2021 by Robindonne

[Robindonne]

Btw, i ended up buying this focuser used for about €160,- incl their motor solution:

https://www.teleskop-express.de/shop/product_info.php/info/p7106_TS-Optics-2--UNC-V-Power-Crayford-Focuser-for-2--and-3--SC-Thread.html

The focuser is new around €260,-

They sell the motor option for an additional €180,-, but when you look at that motorset you’ll recognize that its just that simple dc motor again, only with an extra toothed belt+pulley and 2 aluminium (riser) blocks.  

I remember buying some extra belts and various sizes pulleys on aliexpress for some euro’s.  5? For spare but also to try different transmission speeds. 
 

All worked okay but ending up selling the focuser. I want to have the options for automated focusing so looking around for a nice other solution. Also the dc motors aren't that accurate. 

Edited May 26, 2021 by Robindonne

[Louis D]

I would recommend the 35mm Aero ED for a widest field eyepiece in that scope.  I believe TS-Optics has it in stock as the UFL based on a recent post here on SGL.

[nfotis]

49 minutes ago, Robindonne said:

Btw, i ended up buying this focuser used for about €160,- incl their motor solution:

https://www.teleskop-express.de/shop/product_info.php/info/p7106_TS-Optics-2--UNC-V-Power-Crayford-Focuser-for-2--and-3--SC-Thread.html

The focuser is new around €260,-

They sell the motor option for an additional €180,-, but when you look at that motorset you’ll recognize that its just that simple dc motor again, only with an extra toothed belt+pulley and 2 aluminium (riser) blocks.  

I remember buying some extra belts and various sizes pulleys on aliexpress for some euro’s.  5? For spare but also to try different transmission speeds. 
 

All worked okay but ending up selling the focuser. I want to have the options for automated focusing so looking around for a nice other solution. Also the dc motors aren't that accurate. 

 

Thanks for the suggestions. The idea of adding  (in a future) a pulley/belt set to that same motor appeals to me.

For automated focusing, I am under the impression that the ZWO EAF (the new 5V version) is adequate, and cooperates with most everything (not only ASIair), without it being too pricey.

But I wanted something simpler and cheaper as a first step for accurate focusing without shaking the OTP and requiring one more USB port from a computer.

 

N.F.

 

[Robindonne]

Google a bit.  Google motor focuser skymax180 will show you all sorts of belt driven focusers.  Even this one from this forum. Not sure who is the owner from the picture but its from a member.   Using a dc and pulley/nelt combo attached to the finderscope bracket. 

[nfotis]

I know about this solution, but since I already have the monorail focuser available, why not use it (and avoid mirror shift etc)?

At any rate, I ordered the motor (along other stuff), will see how it works...

N.F.

Edited May 27, 2021 by nfotis

[Roy Foreman]

With my SW 180 Mak and my Celestron 8" Edge SCT,  I use the electric focuser from a Meade LX200. It just screws onto the back like any other SCT accessory and takes up less back focus than a crayford focuser. Does the job nicely, albeit sounding like a coffee grinder.  Mine came with an LX200 (obviously) but I think you can buy them as a separate unit. I also purchased a dedicated hand controller for it from Telescope House, but  I am not sure if they still make them.

[nfotis]

Some lunar images shot via the Skymax 180 a week ago (first light), with an ASI462 camera.

These should give an idea of its capabilities.

Typical parameters: shot 3000 frames video, stacked in Autostakkert!3, did some Unsharp Mask in GIMP of the half-sharpened image (haven't mastered Registax yet).

N.F.

 

[Robindonne]

Perhaps search for a radius block to attach the motor to that “non” compatible crayford.  And use a belt to control the focusknob

[nfotis]

4 minutes ago, Robindonne said:

Perhaps search for a radius block to attach the motor to that “non” compatible crayford.  And use a belt to control the focusknob

 

Will see when I receive the package.

If the Orion manual of the Accufocus is to be trusted, I shouldn't have any problem mounting on this GSO/TS focuser.

If you look also at the product photos, it doesn't look incompatible to my eyes:

https://agenaastro.com/gso-2-linear-bearing-crayford-focuser-for-scts-dual-speed.html

N.F.

 

[nfotis]

On 23/05/2021 at 04:20, GazOC said:

A Crayford adds a fair bit of weight to the setup. I found it useful when I was imaging with my 180 Mak/ HEQ5 setup but not visually

If I remove the visual back and the Skywatcher 2" diagonal, the difference isn't that great I think. I haven't weighted both, but it didn't feel much different. And it has a proper 2" to 1.25" adapter, with brass ring (the Skywatcher one is really bad, I threw it in the garbage can).

N.F.

[nfotis]

Two more photos, this time with an ES 2x Barlow in front of the ASI462 camera, I think I recorded 3000 frames. F/30 isn't ideal, but it seems to work, somehow.

Stacked in Autostakkert!3, sharpened in Registax.

These are my first ever stacked photos of Jupiter and Saturn. Used also a ZWO ADC, to reduce the atmospheric dispersion. Consider these a first effort, with so-so focusing etc.