Re: [APML] needed- an excellent sense of direction

["John C. Mirtle" <jmirtle@shaw.ca>]

No question about it Bobby, the most solid connection when attaching stuff to
tubes I have found to be with using 2 screws. I always found a slight bit of
movement in the camera when using 3 screws, and a slight rocking motion when
using one. I agree with Dave on the spacing, 2 screws 90 to 120 deg apart will
put good pressure against the drawtube wall. If you are using an OAG, the entire
length of the guider body inside the drawtube becomes the third contact point -
not just a small screw tip. This is something you can fiddle with when the moon
is up - certainly worth checking out. I wasted many, many hours of hand guided
prime focus shots until this simple observation hit me.

John Mirtle
Calgary, Ab. Canada

----- Original Message -----
From: "Bobby Middleton" <bobm@koyote.com>
To: <astro-photo@seds.org>
Sent: Thursday, January 10, 2002 4:15 AM
Subject: Re: [APML] needed- an excellent sense of direction

>
> Registar. The pattern is on both negatives and is similar. Three screws are
> bad huh?? That's a new one on me. You were getting some flexure on your
> shots? Do you agree with Dave on the placement; 90-120 degrees apart?
> Bobby



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