During my exploits with astrophotography I have found the errors in my drive ( 24 sec peak to peak) could be corrected with a autoguider but did make life difficult and had to do corrections every second , so I decided a upgrade was required.
After some research the Telescope Drive Master seemed to offer what I was looking for , a hardware kit that could offer tracking up to 1 sec +or -
after receiving the kit I made a adaptor to connect the encoder to my RA ( sec pic 1) , even though it may look a bit rustic I spent quite a while getting everything as true as I could.
Below is the Encoder fitted to RA and spot the tin foil I used as a packing Plus I bet I was the first person to use a jackhammer to fit one , I had to chop a hole in the floor .
needs a tidy up I know !
TDM Drive Box
I connected every thing up and let the TDM do a self calibration which takes a few seconds and was amazed to get 2 sec peak to peak first go and with a small amount of fiddling got the promised 1 sec + - ( see next slide)
How does the TDM work ? As you can see there is a high resolution encoder that is fitted to the RA shaft of your scope, this encoder is capable of 1/8 arc sec resolution.
These reading are interpreted by the box of tricks
( slide 2) and real time corrections are sent via the autoguider input at up to 5 Htz
The TDM is a self operating piece of kit requiring no input from a computer unless you attach a autoguider.
You might ask what do you need a autoguider , well the TDM is not magic and can not see and therefore correct things like incorrect polar alignment , refraction , bendy scopes etc
so in practice I use guider corrections every 20 sec or so no great hardship .
The TDM will not be for everyone as you will need a decent mount to start with and of course cost may be a issue but in my opinion it is worth every penny
I would like to thank Attila of TDM for his kind and considerate help in setting up
I then took a trial unguided sub , 600 sec at 1350mm FL
I was more than impressed Unguided round stars Amazing stuff !
A happy man am I, it has turned my rather ugly beast into a tracking monster