41.2" Newtonian Telescope - page three

This is a view looking down the business end of the telescope. You can see the primary mirror, unaluminized. Behind it you can see the 27 point floatation pads in white. These are 2.5" across. The cell is made from 1" square steel tubing welded together into a cage framework. The triangles are 3/8" aluminum plate. The plywood of the mirror box is assembled around the steel framework.

Here you can see the upper tube assembly close up. The outside diameter is 48". The white pieces are teflon dowels which make up part of the rotation assembly.

After viewing through tall telescopes for a while, the biggest source of fatigue is crouching or stretching to look through the eyepiece because the rungs of the ladder do not put you in proper position for comfortable viewing. The rotating diagonal cage will solve this problem.

The Diagonal itself is a 6.25" minor axis. The spider is a Novak special order. The focuser is a Starlight instruments Feathertouch two speed, with a 10:1 reducer knob for critical focusing. The whole diagonal cage weighs about 25 pounds.

The base seen here takes the place of a ground board in a Dobsonian. Although my telescope resembles a Dobsonian, it is really a driven Alt-Az design. The base is on wheels for ease of mobility. One of the large wheels can be seen. There is another on the other side. Under the other two corners are casters. The shaft that sticks up is the pivot for the rocker box. There are two roller bearing assemblies on the near end, and a driven friction shaft on the far side of the photo. You can see the base is only as big as it has to be, and sits under the telescope off center.

Both the altitude and azimuth drives are shown in this close-up photo. The upper assembly is the altitude drive. The stepper motor is the object angled away from the viewer. This is connected to a right angle 30:1 gear reducer, which in turn drives the shaft which rotates against the altitude bearing side. The drive assembly is mounted on a shelf securely attached to the rocker box.