Balancing a scope for motor drive use

[redneon]

I'm just about to balance my scope before I start using my new motor drive. I understand I have to loosen the R.A. and Dec locking knobs before I balance each respective axis but nowhere in the instructions does it mention it should re-tighten these knobs. Should I just leave them untightened? Or at least just the R.A. knob as that's the axis I attach the motor drive to.

[brantuk]

You balance one axis at a time whilst keeping the other locked. Lock the RA horizontal then balance the dec by moving the scope up/down in it's rings till it balances.

Then lock the Dec vertical and balance the RA by sliding the weights up/down the bar till it no longer rotates. Make sure you have any accessories you intend to use, attached to the scope before balancing.

Once it's all balanced make sure the motor is disengaged, unlock Dec and RA and swing the scope round till it's on the object. Then lock the clutches and engage the motor. If you've polar aligned the mount it will track the object in RA with odd tweaks in Dec now and then

[redneon]

So it's ok to leave the Dec cable connected? I assumed that once the scope is polar aligned you shouldn't really be playing around with the Dec axis otherwise you're effectively knocking it out of alignment, aren't you?

[brantuk]

Once you have polar aligned it's the Alt and Az adjusters that have to remain constant. Also the tripod cannot be moved for the entire session or you'll have to redo the polar alignment.

Then you are free to use the RA and Dec to move around the sky at will. Just make sure the motor is disengaged first before slewing around and have the RA and Dec lose - do them up again once on target. I take take it you have something like an EQ3 or EQ3-2 mount? Maybe with a 130P or 150P scope on it?

(If you have a Dec cable then yes you'll need it. Also when you engage the motor ensure the RA is locked.)

[redneon]

Cool, cheers. I get it now. Presumably the Alt/Az controls are effectively the latitude setting and where I can turn the mount on the tripod? It's only a basic scope as I'm still a newbie. A 114mm reflector on an EQ1 mount.

I have had the scope for a year but never got round to polar aligning it. I just left the mount at default settings and used it as an Alt/Az mount.

[brantuk]

Ah I see - yes alt/az are basically latitude and compass bearing of the mount. If you point the mount due north and set the latitude, you will be very roughly polar aligned - good enough for observing at least, And you're tracking motor will work a lot better.

You can get a fair bit more out of the scope for the sake of knowing a few basic things. Hope I've helped and good luck

[tony]