Added a declination axis to the tracker

This project is never going to end…..

I have been very busy at work over the last 10 months and have done very little with my projects or even observing under the night skies. Over the Christmas break I started a little project to add a declination axis on the tracker to be able to install my Orion 80ED. It looks a bit weird but it works a treat.


The new dec axis is based on another 20mm mild steel rod that is clamped in a 40 x 40 x 80mm aluminium block that is mounted on the RA axis. This dec arm is currently locked in place by tightening the split block with two allen key screws. Not very elegant but rock solid. The dec axis is long enough to handle a counter weight but when I used it, I did not have any counter weight on and the system handled it without any worries. I think that it may be able to take my Meade 8″ SCT telescope if I add a counter weight as well.


When I tested the new setup I was battling like crazy to get a guide star in view and in keep it in focus. It would really be a good idea to buy a proper guide camera to do the job properly. The webcam is ok to start with but it’s frustrating when you are trying to change to a new target quickly. The sensitivity of the webcam is not great. In a dark sky it works reasonably well but in a polluted sky it’s no good. Hopefully I can afford to spend a few hundred dollars on a dedicated autoguider camera with a ST-4 port, it would make the guiding experience much easier.  Does anybody have any recommendations for a good camera?


I almost forgot, I have now effectively locked down the RA axis and I don’t have a clutch on the RA axis. I have to drive RA with the motor to point in any particular direction. I have added a switch and some new code on the stepper driver box to allow me to change the stepper motor speed to slew the RA axis faster or slower. It works well but I wont be able to handle a crowd at a star party with this setup!

4 thoughts on “Added a declination axis to the tracker

  1. Dasphys

    Do uou have a blog about the process of star photography using this setup from start to finish, setup to photo ?

    1. Theo Post author

      No I don’t. I will see if I can write it up with photos. Its very cloudy at the moment and I have not been able to go out recently.

    1. Theo Post author

      Hi Bov,
      It was a great experience to build the tracker but I’m now focusing on taking photos with a commercial mount. I really loved the challenge of designing and building the mount myself.

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