I am in the process of designing and building an equatorial mount for tracking and guiding of a DSLR camera + lens and/or a small telescope (perhaps up to an 8" SCT optical tube). My iOptron Skytracker is great for shorter lenses and exposures but I cannot load it up too much before it runs out of steam. I want a tracker than can manage an 80mm refractor or up to an 8" SCT optical tube assembly without throwing its toys out of the cot. I know I can go out and buy an EQ6 but where is the fun in that?
I don’ have a final design yet, it's a work in progress but you might find something of interest. I have built and tested a few versions already and assembled the electronics for a basic RA tracking mount using a stepper motor drive that uses an Arduino to control the stepper motor. I have also implemented autoguider functionality on the RA axis that is working quite well. All details are available on my blog.
I am machining my own worm gears and worms as well and it’s a "journey of discovery". I am busy on my third iteration of the mechanical design and I am now trying to cut a new 130mm worm (~204 teeth) gear pair with an ACME thread. I have used M10 stainless steel threaded rod before but have found that it is important not to cut the M10 thread too deep into the aluminium worm gear disk. It causes the M10 worm to bind very easily when the worm/gear assembly alignment is not absolutely perfect. I am now trying out a 10×2 mild steel threaded rod with an ACME thread (10mm diameter with a 2mm pitch). The ACME thread is much more suitable for a worm gear than the M10 type thread.
You are welcome to take a look at my progress at
https://starsinphotos.wordpress.com/
Advice and comments will be appreciated.
Cheers