Tracking without GOTO

[Akyra]

I know I've been starting new topics left right and centre but I have lots of questions to ask and the forum is the ideal place to get them asnwered, hope you guys dont mind.

One of the most annoying things about my scope is the constant 'drifting out of the FOV' problem. Is there any way I can have the tracking but not the GOTO? I am quite willing to build something myself from scratch (which I already have a few ideas for) as at the moment money IS an object .

I've seen links for EQ platforms, obviously buying a motorized EQ mount (out of the question at the moment), changing the scope (already been down this road - decided against it)

I've got a few semi-powerful small motors that I think I could rig up on the azimuth and altitude, and gepetto's project thread for dob setting circles, to create my own motorized tracking / manual GOTO 'pulley system'.

What I would also like to know is how much the motors need to move? I know that the earth rotates .25' a minute, but does that mean both axis move .25' every minute, or .125 on each axis every minute?

[SteveL]

If your scope was polar aligned and on an equatorial type mount, then you would only need to track across the sky in one direction at the exact rate the earth rotates.... but you are in AltAz on your dob, so you need to track in both direction at the same time, and it requires some maths to be able to keep an object in view all the time because the two rates vary depending on time of day, location on the earth, etc. I`m not great on the whole maths part of orbital mechanics, but i`m sure someone will be along shortly who is

[Akyra]

I thought about building a solid wedge, much like a door stop, and put my scope on that. I would only need to move the scope along the azimuth axis then wont I?

[Kaptain Klevtsov]

Check these out.

http://www.astrosurf.org/magnitude78/TelStrock/planche.html

http://www.biophysik.uni-freiburg.de/Reiner/ATM/atm.html

http://tech.groups.yahoo.com/group/eqplatforms/

http://www.geocities.com/reaganjj/

http://members.aol.com/NGC704/EQPlat.htm

Just to get you started.

Captain Chaos

[themos]

Akyra, do you have any experience in building such stuff? Metalworking, assembling, designing, circuit board making?

I don't have a tracking mount but I can do quite a lot of imaging without it, as long as the target is bright enough (sunspots, moon, planets, star clusters).

[GordonCopestake]

check out roundtable platforms too. Expensive but you can take some ideas from them