Re: ATM Holographic Laser collimator on budget.

["Bill Prewitt" <bprewitt@neo.rr.com>]

I tried Sam's holographic collimator idea, but with no machining at all.
It probably won't get any cheaper or simpler than this.

I cut two 3/8" lengths of thick plastic tubing and slipped them over the ends of
an $8 laser pointer with no-smoking circle head. The tubing makes a resilient
pad for the collimation screws.

I had an 8" length of 1 1/4", thick-wall aluminum tubing left over from my truss
tubes.
I drilled and tapped 3  8-32 holes 1/2" in from the rear, and another 3 holes an
inch up the tube.
These six screws let you collimate the beam as you rotate the tube in a V block.
One additional hole for a screw over the pushbutton lets you turn it on and off.

The thing works great !

Since the tube is open, the beam projects out the aperture and also reflects
back to the focuser tube past the laser.
You can center the shadow of the laser in the focuser hologram circle while also
centering the secondary shadow in the main aperture circle.

         Bill Prewitt

My webpage of telescope making and caving
http://home.neo.rr.com/imaging

>
> Six set screws (three in the front and three in the rear are used to adjust
> the laser so the the beam does not move when the unit is rotated.
>