EQ Platform with Solar scopes

[Stu]

I often use my PST Mod and Tak/Herschel Wedge scopes on a dual clamp Ercole and Gitzo tripod as it is very quick and convenient to setup. With two sets of binoviewers involved, it can be a little sensitive on the balancing and constant nudging at high power is a little tiresome.

Ideally I would have something like an AZ100, but funds don’t allow that currently, so I thought I would try my EQ platform to give me tracking. Stability is an obvious concern, but by only extending the tripod legs a little way, I found a position that was stable, with the legs positioned as far apart as possible. The rubber feet on the tripod grip well, and I also added two bungies looped onto the hook under the tripod head and hooked onto the edge of the platform. That made everything very solid and stable. Finally I used a counterweight device I put together some time ago which fits to the vixen dovetail on the PST Mod, ahead of the mount and hangs below the scope. This gives excellent balance for the binoviewers which stick up a long way from the axis of rotation. With this setup, I could move the scopes in any position and they stayed balanced.

To avoid having to change the battery on the EQ Platform, and to give me a rechargeable option, I put together a little harness made from a 9V battery clip to a jack socket, then bought a USB to 9V converter cable so I can now run the platform off any power bank type battery, including my Celestron Powertank. Very handy, and means I won’t run out of power mid session now, although the batteries do last quick a long time as it is.

So, did my craziness pay off? Absolutely! I was able to get comfortable at the scopes on my observing seat, and the tracking accuracy was excellent. It allowed much better views as I wasn’t constantly nudging the scopes. Last night I tried the same setup, with the Heritage 150p replacing the PST Mod for a lunar session. Again, the tracking at high power made a big difference and gave me a much more relaxed session, only needing to move the scopes to change target on the Moon.

The EQ platform I have is a Watchhouse, and is quite large so it does allow the tripod legs to be spread a decent distance apart to keep it stable. I’ll certainly do this more often. The picture shows it while I was setting up, before I added the bungies which gave me much more peace of mind that the whole thing wasn’t going to topple over 😱. I would only attempt this with a dual scope setup, or a well counter-balanced single setup to ensure stability!

[westmarch]

Where there’s a will there’s a way.  Well done 😀

John

[Stu]

This has been working well through the day, tracking well. I put a 5kg weight on top of the platform just to ensure it was stable. No problems despite the gusty wind.

[westmarch]

What is the transit time on your platform? I used to worry when I had to reset mine thinking it would topple over but it has proven remarkably stable with recesses for the feet of the scope to sit in.  You look as though you have belt and braces with bungees and weights! 👍

John

[Stu]

I’ve not timed it but around 45 mins I think. Very quick to reset and it cuts off when it reaches the end stop. Works well.

I have had a scope fall off it before, when not counterbalanced correctly so am a little cautious!! 😀

[Highburymark]

Ingenious! 

[AlexK]

Ah! That's why you've got four eyes! :)))

That solution is well known actually. But instead of bungee cords people are properly lowering the CoG of the system to resemble the telescope CoG height (the most crucial parameter of any EQ Platform design). A good piece of steel or lead secured in the center of the platform is all you need. Better yet would be to stress tripod's legs by hanging the weight from its top center. That way the CoG will follow the gravity as the platform moves, which would allow to use less weight (required to counter that small shift). For the legs' skid security, I would just drill large enough holes to sink the legs ends in them, or screw down three tall rings surrounding legs' ends (eg. some wide enough bottle caps should work perfectly there.

[Mr Spock]

EQ platforms are surprising effective. Every dob owner should have one 😜

[Louis D]

18 hours ago, Mr Spock said:

EQ platforms are surprising effective. Every dob owner should have one 😜

The question becomes, why are there so few affordable options out there in the astro marketplace?

Edited April 23, 2021 by Louis D

[Stu]

16 hours ago, AlexK said:

Ah! That's why you've got four eyes! :)))

Yes indeed 🤣🤣

[Mr Spock]

1 hour ago, Louis D said:

The question becomes, where are there so few affordable options out there in the astro marketplace?

Maybe there's a manufacturing opportunity for someone there. Most seem to be home made, you don't see many pro made for sale.

[AlexK]

3 hours ago, Louis D said:

The question becomes, why are there so few affordable options out there in the astro marketplace?

My point exactly. $1000-2000 for a metal one. I can buy a car for that.
I guess, that's "novelty". For many folks it looks like an extremely sophisticated mind-bending high tech. I saw many unable to grasp how it's actually could track the sky. Manufacturers just leveraging that opportunity shamelessly :)))) A decent visual EQP can be built for under $100 even today from random scrap you can find at any hardware store.

Re "everybody should have one": I'm living without that tech just fine for over 12 years (since I went all manual with my z12). That's because I have no single problems manually guiding my classic 12" sized Dobson design build all the way to 420x to be concerned about tracking in general. Not looking into imaging with it, nor sharing it a lot with others. Pointing and IDing objects takes just seconds with my Telrad flow, so no tracking needed to be able going away for consulting with charts for long either.

But definitely, if your telescope is not actually a classic Dobsonian (has any ball bearings, brakes, motors) just looking like one, which means it's not easy to move it around the sky without the view shaking, drifting, and sticking, you may benefit from it for sure. Same if you need sharing the view with others lacking any telescope handling skills (kids, outreach) often, or don't know constellations so have to hunt DSOs starting from the Planisphere disk :)))

I do have plenty of skills, tools, and materials, all the way to the 3D printer on my side table. So I think I could build a decent platform in a single weekend or two. Just not motivated enough. Also, being a nomadic-type observer :))) I see it as just a burden to haul and setup in the field every time, stay on alert not to kick my scope off it in the dark, and then clean it from dirt and crawlers after the expedition...

Edited April 23, 2021 by AlexK

[Stu]

2 minutes ago, AlexK said:

But definitely, if your telescope is not actually a classic Dobsonian (has any ball bearings, brakes, motors) just looking like one, which means it's not easy to move it around the sky without the view shaking, drifting, and sticking, you may benefit from it for sure.

I specifically bought mine to use with my 8” f8 Dobsonian. Whilst it is a fairly ‘classic’ Dobsonian, it is also pretty tall and spindly, with a narrow base for its height. It tends to wobble around a bit when nudged, so does benefit a lot from the tracking. The views are well worthwhile though. Nice review of a similar scope here:

http://www.scopeviews.co.uk/OrionOptics200Dob.htm

[callisto]

20 hours ago, AlexK said:

I would just drill large enough holes to sink the legs ends in them, or screw down three tall rings surrounding legs' ends (eg. some wide enough bottle caps should work perfectly there.

I use washing machine vibration pads for my Dob's feet  😀

[AlexK]

30 minutes ago, Stu said:

I specifically bought mine to use with my 8” f8 Dobsonian. Whilst it is a fairly ‘classic’ Dobsonian, it is also pretty tall and spindly, with a narrow base for its height. It tends to wobble around a bit when nudged, so does benefit a lot from the tracking. The views are well worthwhile though. Nice review of a similar scope here:

http://www.scopeviews.co.uk/OrionOptics200Dob.htm

Very close to classic scheme indeed. But your "anamnes" is correct. The Dobsonian rule of thumb for the base is 2D minimum (and 1D for free-standing trunnions). That OOUK rocker's base was "improved" to be more compact.

[John]

56 minutes ago, Stu said:

I specifically bought mine to use with my 8” f8 Dobsonian. Whilst it is a fairly ‘classic’ Dobsonian, it is also pretty tall and spindly, with a narrow base for its height. It tends to wobble around a bit when nudged, so does benefit a lot from the tracking. The views are well worthwhile though. Nice review of a similar scope here:

http://www.scopeviews.co.uk/OrionOptics200Dob.htm

The base of my 12 inch dob is modeled approximately on the OO base design but carefully made from quality plywood. I suspect it's footprint is a little larger than the OO version would be but not by much. Each time I use the scope I offer a little vote of thanks to @Moonshane who made it for me

While being very smooth in both axis, it also does that other vital thing which is to hold the scope really steady on the chosen target, even at very high magnifications.

I did own an equatorial platform (made professionally in Cornwall) for a while and that worked well with the scope. Eventually I decided that I could manage well without though and loosing those couple of extra inches of eyepiece height was actually an advantage

 

[Stu]

52 minutes ago, John said:

The base of my 12 inch dob is modeled approximately on the OO base design but carefully made from quality plywood. I suspect it's footprint is a little larger than the OO version would be but not by much. Each time I use the scope I offer a little vote of thanks to @Moonshane who made it for me

While being very smooth in both axis, it also does that other vital thing which is to hold the scope really steady on the chosen target, even at very high magnifications.

I did own an equatorial platform (made professionally in Cornwall) for a while and that worked well with the scope. Eventually I decided that I could manage well without though and loosing those couple of extra inches of eyepiece height was actually an advantage

 

That’s the same model of platform I have John, made by Watch House who are no longer in business unfortunately.

I think the issue with my scope is that it is as tall as yours but with a significantly smaller footprint, so is less stable. The platform makes a big difference to the views I’m able to achieve.

 

[westmarch]

45 minutes ago, John said:

The base of my 12 inch dob is modeled approximately on the OO base design but carefully made from quality plywood. I suspect it's footprint is a little larger than the OO version would be but not by much. Each time I use the scope I offer a little vote of thanks to @Moonshane who made it for me

While being very smooth in both axis, it also does that other vital thing which is to hold the scope really steady on the chosen target, even at very high magnifications.

I did own an equatorial platform (made professionally in Cornwall) for a while and that worked well with the scope. Eventually I decided that I could manage well without though and loosing those couple of extra inches of eyepiece height was actually an advantage

 

Moonshane inspired so many people who watched his trial and error blog and the huge amount of invaluable links he posted .  THE god of equatorial platforms has to be Reiner Vogel though. Nobody has explained it in so much detail and for free.

http://www.reinervogel.net/index_e.html

John