Hi Martin.? I went with the Clough 42 based system. He has several YouTube videos about the design. Basically he sells a kit that has two boards that plugs into a Texas Instruments board and those two boards, well three, one is the remote control, together along with an enclosed optical encoder provide the inputs and outputs to control the speed of a stepper motor that drives the lead screw. He sells his kit on eBay, the Ti board is available from Digikey, Mouser or Ti direct and the encoder and stepper motor and driver kits are available a lot of places. I bought mine from Amazon.? All told I have 420.00 in mine. That's everything including the aluminum to build the mount, screws, belts and pulleys, wiring, etc.? Like I said, not necessarily cheap but for me it's been worth every penny. I got tired very very fast of messing with the gears and this completely eliminates them on the 7x.??I'm very happy with it.? Ryan
On Mar 16, 2022, 5:37 AM -0400, Martin F. Slater <mfslater@...>, wrote: