A Dobsonian is a great design solution for large aperture Newtonian reflectors.

Portability and ease of use are top of my list. In their most basic form they also help learn the sky, which is often overlooked by beginners (and some more experienced observers!)

However, a big disdvantage of the basic Dobsonian is their inability to track objects. This can be frustrating especially when trying to use high magnifications, which are often needed when trying to hunt down some of the elusive fainter objects.

Some commercial Dobsonians are available with tracking drives, and a few add-on kits are also available but they are expensive in the UK and also suffer from having been designed before tablets, smartphones, wifi and bluetooth became the norm. So an American friend (Craig) and I set about designing our own.

Bascially he did the electronics & software and I did the mechanical design and system testing. Starting out as a tracking solution, it quickly became a full ‘GoTo’ system. We use Nexus (also now Nexus DSC) to drive the axis encoders, micro-stepping motors to drive the scope, a handheld joystick box for control at the telescope, and a wifi link to a tablet or pc, running SkySafari (or similar application software).

They worked out really well, and a few other friends asked for their scopes to be “upgraded” with ScopeDog, and now it has found a niche in the UK larger Dobsonian scene. Also available from Craig in the USA.

If you have a large Dobsonian and want a drive system, feel free to contact me.

User Manuals for ScopeDog can be downloaded

Original ScopeDog with Nexus

New ScopeDog with Nexus DSC

Nexus is available from Astro Devices

AstroKeith 2018