Custom fork mount for 30 cm Newton

This project involved the design and construction of a heavy fork mount for an existing 30 cm Newton telescope.

 

At first a layout was made with all physical dimensions. From this layout the phyiscal position and intersection of both axes will be derived.

 

From this position the mount can be designed.

The design will be based on a fork mount, this design has been chosen because it gives a high stability combined with a low weight.

This type of mount also needs the least space and gives the least swing of the eyepiece. Furthermore a fork mount does not use counterweights because the telescope resides in the center of gravity.Besides that the total amount of moving mass is less than with a German mount of this size. 

 

The fork-mount construction means that the pole axis has a relatively low position. Because the observatory is built on a construction with a woorden floor, the mount had to be fixed on a separate foundation frame that itself is connected to the walls below .

 

The​ mount is designed in such a way, that no ladder is necessary when observing in the zenith.

 

The whole mount is constructed from steel. The polaraxis house is a heavy cast iron steel piece of about 80 kg. Inside this piece the 80 mm thick steel polar axis is fitted with two taper roller bearings.

 

​The drive system is a classic wormwheel with extra reduction stage. The total right ascension reduction is 1:1224. The worm-wormwheel combination, as well as the extra reduction stage, are fully backlash-free.

 

​The declination axis is also fitted with a worm-wormwheel combination and also fully backlash-free.