14 inch Horseshoe and Observatory by Mel Bartels

Aperture fever was really kicking in, so I built a 14 inch. Actually I was a victim at an early age, lusting after the 8 inch in the back of the Edmund Scientific catalog. The 14 inch used a simple but highly effective drive system consisting of a worm and gear 30:1 reduction driving a machined drive shaft that the horseshoe rode against. There was no detectable periodic error during guiding. Note the motorized sliding focus board for the main scope and a manual sliding board for the 4 inch auxiliary scope. I used a double diagonal guiding arrangement of my devising, where the camera's diagonal was made purposefully slightly undersized, allowing a bit of light to escape around the edges where it was collected and used for guiding. This reduced the light going to a camera to an aperture of 12 inches, but sent light equal to a 7 inch scope to the guider. Besides the bright guiding image, I could also guide exactly on the object I was imaging - no off-axis star images here. I also built a color enlarger, large format projector and a blink comparator. I used sonotube for the tube and 3/4 inch Birth plywood for the mount. As you can see, the tube rotated on bearings.


Home built color enlarger, blink comparator and slide projector for large format slides.

Homebuilt cold camera capable of handling rolled film. Pictured are all the parts for the cold camera before assembly and painting including the aluminum body and plastic parts. Look at the eyepieces I used in the late 1970's, some Konigs and Erfles - a far cry from today!

An example of the cold camera prints from the scope, camera and enlarger. A 5 minute unguided astrophoto of M42, taken from the suburbs.

I moved the 14 inch to a roll off observatory, where the entire observatory moved on plastic pipe.