Re: [APML]: Byers drive

[Chuck Vaughn <aa6g@aa6g.org>]

Mike,

>I was wondering if the motor itself comes off of the reduction gear unit
>or if they are an integral unit. I can take the motor and reduction gear
>off with 2 screws, but don't see a way to take off just the motor.

You want to take off the little spur gear from the motor shaft? Isn't it
pinned on? I can't see mine without disassembling the whole thing but I
know it's possible to get it off.

>When I asked about exposure times, I meant the exposure times for your
>autoguider. I figure that the better the drive the longer the guider
>exposures you can use and thus, the easier it is to find a guide star.

Generally I stick to 1 or 2 seconds. Up until Hale-Bopp in March I had
never manually guided a photo with the 11 5/16" drive. My ST-4 was in for
repair and I wanted to get a couple of photos. It was so easy to guide
manually I couldn't believe it. It was such a struggle with the old 10"
drive. The March photos of H-B on my web page were all manually guided.
The star trails are all straight, none of the wigglely lines you see on
most manually guided comet photos. Those other people must have had terrible
drives. :-)

>I get the impression
>from Astromart that DC steppers are more expensive than AC synchronous
>motors. Would that be right?

I'm not familiar with the prices for DC stepper motors.
>
>How is the $1000 price tag on this drive. Would you say it's an average
>price or a good price? It's a brand new, unused drive.

That's a *good* price. I paid $1250 for mine. That gear is far better 
than anything you'll find on any commercial scope. 

Chuck  <aa6g@aa6g.org>