Equatorial Platforms

[athornett]

Hi All,

I thought I'd start this thread to seek your thoughts on merits or otherwise of equatorial platforms. I made one few years ago for my 12" L/B dobsonian. It was certainly a voyage of discovery and proved to me that I am capable of making such a complicated object. However, as a method of observing the stars I am not sure. This is not because it does not work but rather because I don't use it. To me, dons are all about taking them outside and observing quickly and easily without hastle of alignment. I realise other people may not share this view and so please can you add your comments to this thread so we can decide together when and where an eq platform is useful.

Andy

[John]

I have a commercially made EQ platform which I use with my 12" Orion Optics dob. I posted about it here:

http://stargazerslou...orial-platform/

Set up time (about 2 mins) is a minimal additional overhead for the benefits it brings in high powered observing I feel - I can relax and view at 300x with just the odd nudge to re-centre an object every 10 minutes or so. It makes studying the planets much easier and I feel I can pick out more detail when using it.

I don't tend to use it for deep sky observing and the additional height of 5-6 inches does mean that I need a shallow step to reach the eyepiece when viewing in the zenith area.

Overall I'm very pleased with mine. Storing it can be a slight headache though as it's quite a bulky bit of kit and I don't have a shed at the moment.

[athornett]

I find that a problem too - the need for extra height - so summary so far:

Advantages

(i) Ability to observe objects at high magnification withuot losing it from FOV

(ii) Easier to show group of observers object in eyepiece - eg star parties, outreach events

Disadvantages

(i) High mag not particularly helpful for DSOs

(ii) Need for small step to compensate for extra height required, perhaps makes it difficult to use observing stool

(iii) Risk of scope falling off! Happened to me once with a commercially made platform from USA - not my home made one I would like to add!

(iv) Need to re-set every 20-60 mins dependent upon platform

(v) Storage issues for ungainly awkwardly shaped device (but we are used to them as amateur astronomers aren't we?)

It would be great for as many people as possible to comment on these and other issues. what is important to you and why?

Andy

[athornett]

By the way, John - I read your report on the Watch House Platform - it does look nice and sound like a well made piece of kit - perhaps for anyone wanting to buy such a platform this is the way to go!

Andy

[Jiggy 67]

Well the obvious case for EQ mounts is if you intend to get into imaging, for that they are essential. Other than that, its personal preference. You've already pointed out the benefits of a DOB, just pick it up and put it down and away you go. They are easy to store, like John, my EQ5 is a nightmare to store and if you don't get your alignement right, with a GOTO, you can spen hours phaffing about......in fact, I don't know why I havn't got a dob!!!

Oooops, sorry,I though you were referring to an EQ mount, totaly misread that!!

[Scooot]

My scope being smaller, raising the height is an advantage. As mentioned they come into their own whilst studying objects on higher powers, no nudging etc, but once I've decided to get it out it doesn't matter what I'm viewing as it just keeps the object in the FOV which is obviously an advantage.

The main disadvantage to me is that I need a very accurate setup if Im using my push to system. If using the dob manually set up is quick and easy.

[athornett]

No problem, Jiggy.

Thanks for making the effort to put a post onto this thread.

Andy

[athornett]

Hi Richard,

You mentioned that having a smaller scope means that height of the EQ platform is not an issue for you. Can I ask you what scope you use and what height you observe at? Do you use an observing chair or stand at the scope?

Andy

[Moonshane]

I made my own for my 6" f11 dob and added threaded inserts to allow the scope to be bolted in place; it's quite tall and slightly top heavy and is much sturdier this way. one day I might add some Teflon pads and a central bolt for use with my 12" f4.

http://stargazerslounge.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=34815

[Scooot]

Hi Richard,

You mentioned that having a smaller scope means that height of the EQ platform is not an issue for you. Can I ask you what scope you use and what height you observe at? Do you use an observing chair or stand at the scope?

Andy

10" orion optics 1200mm focul length dob. I'm 5'9" and stand, the platform puts the scope at an ideal height for me. I can see why it might be an issue for larger scopes.

[athornett]

Hi Richard,

Have you tried using DSCs with your eq platform?

Andy

[Scooot]

Hi Richard,

Have you tried using DSCs with your eq platform?

Andy

Hi Andy

yes last year I was using it all the time. You need to align the platform very accurately to maintain "finding accuracy" throughout the tracking run though. So I used this method to ensure the platform was perfectly aligned to the NCP and to set the latitude precisely. Then Drift align if necessary to correct the speed.

look at the bottom of the link, I got quite used to it and it didn't take that long

http://www.astrosurf.com/aheijkoop/Equipment/EqPlatfor2.htm

The finding accuracy of the DSC is more consistent though without using the platform. No matter how accurately you align the platform the finding accuracy will deteriorate a little throughout the tracking run but you get to know by how much and compensate accordingly.

[athornett]

That is very helpful analysis of DSC with EQ - thanks for that - it will help with mine.

Andy