Dobsonian equatorial platform angles?

[ofranzen]

Hi all,

I'm playing around with the idea of a dobsonian equatorial platform and have been looking at a number of designs online. One thing I cannot find information on though is how the angles should be adjusted to the latitude. 

Does anyone here have plans for a platform where this is shown? Any plans with measurements would be highly appreciated. I could probably work everything out from pictures but it would be nice to not have to.

Many thanks in advance.

/Ola

Stockholm, Sweden

[Stub Mandrel]

At the equator, latitude 0, the base needs to lie on its side to align with the pole, 90 degrees.

At the pole, latitude 90, the mount points straight up, 0 degrees.

The general formula for setting an equatorial mount, equatorial wedge etc. is therefore 90-latitude degrees.

[knobby]

The base of the mount needs to aim at North celestial pole ...

So for you it would be 59.32 degrees

 

[Stub Mandrel]

1 hour ago, knobby said:

The base of the mount needs to aim at North celestial pole ...

So for you it would be 59.32 degrees

 

The axis of the scope needs to be at 59.32 But the angle of the base wedge needs to be 30.68 degrees...

I found this thread which includes a diagram:

 

 

[Nyctimene]

Two construction plans of VNS equatorial platforms can be found on Reiner Vogel's excellent website:

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

(search for "platform for my 22-Inch Lowrider Dob")

Hth.

Stephan

[Moonshane]

I presume you are talking about an equatorial platform not wedge for your dob. 

The top plate of platform at it's mid travel point will be horizontal. The angles are taken care of with the angle of the front (north) sectors. As stated above the angle is calculated at 90 degrees minus your latitude. Depending on how accurate you want it you will have an easier time in my experience building in some slight height adjustment at the south pivot. Once this is set though it's more or less permanent unless you move latitude.

Here's my thread which ebbs and flows a bit, I made some mistakes etc, and eventually gave me a platform which tracked for about 45 minutes if I bothered to line it up properly. Usually I just plonked it roughly north facing and it tracked for 20-30 minutes at 300x.