DigiTwist is an experimental 2 axis satellite tracker, primarily for the HamTV transmitter on the ISS. 2 broadcast satellite dish positioners are connected together and are controlled by a dual Diseqc pcb. The estimated cost of the 2 positioners, the joiner bar and the controller is £130.
It is experimental in the sense that the satellite positioners were never meant to be used in this way and may fail. Development is continuing, particularly as to the size of the dish that can be carried. The 40cm dish shown is just for demonstration purposes. It has not yet received the ISS, mainly due to lack of opportunity.
More construction details, for early adopters of the test version of the Diseqc control pcb, will appear here shortly. The most difficult part is the drilling of the complex shape of the positioner rotor arm in the joiner bar. Quotations are currently being sought for production of a batch.
If anyone can think of any improvements, particularly ways of joining the positioners together, please comment on the DigiTwist thread on the BATC forum. http://www.batc.org.uk/forum/viewtopic.php?f=2&t=5181
A presentation was given at CAT17: https://www.youtube.com/watch?v=qC8CSi8kZTs