Optec ThirdLynx QuickSync FTX40 Motor (for 3.5" FT focusers)

I find it is better to use an electronic focuser so that I do not have to touch the optical tube, especially under high magnification. There are other cheaper focusers on the market, but after using this, I cannot see buying cheap. This focuser is a very high-quality product. It is very well-machined and fits beautifully on the Feathertouch focuser. I have used it three times now, with the included app, with ASIImg, and with NINA. The minimum focuser step size is small, so I see changes in the star size with a step size of about 50 out of 35000. I have used the focuser with autofocus in NINA and this was surprisingly easy to set up. NINA autofocus found the minimum star width on the first try with no adjustment of the AF default parameters. I am also very pleased that this focuser was designed with a clutch, so I can focus in and out manually, which really helps since I switch optics between visual and imaging. In summary, this is a very high-quality product and I am very pleased with it. For ease of use and quality, I give it my highest rating.

I had to use some copper shims to allow the clamp to be tight enough on my 3.5" Feathertouch knob. Otherwise it works great. I haven't yet programmed the temperature compensation feature.