Satnogs Rotator V3.1

Hi all, I am building the V3.1 rotator and having a lot of fun. What a great resource!

I have some thoughts and questions.

First, the instructions are all for V3, which is fine as that is the official release. Are there prototype Wiki pages for V3.1 which I can update with any changes or edits? Should we create them if there is not?

V3.1 did not have any imperial parts, so I have recreated those. The parts I have fit over standard white PVC pipe. I used 37mm internal diameter bearings. If anyone else needs the latest imperial parts I could supply. How do we store those, or are they just shared separately?

I built the V2.2 PCB and have a spare if anyone wants one. In fact I built V2.2 because that was what was uploaded to Oshpark and linked from the instructions. I didn’t realize until later that there is a V2.4. I looked at the PCB but I’m unsure what changed. Can anyone summarize it? Do I need to make any changes to the V2.2 PCB?

One final question. I have been using the terminal, but I want to use RS-485 for the actual installation. Do I need to use an RS-485 hat for the PI or is there another way to connect it?

Anyway, everything is working for one axis. I used DC motors. I printed in PETG. I can issue the commands from the terminal and it seems to do the right thing. Which is great. Here it is on the bench:



Hey! Nice build!! :rocket:

This is a wiki page for v3 (family) rotator and has instructions for v3.1. v3.1 it has some minor issues.

We have took the decision to not maintain imperial parts. But in v3.1 we have as requirement to reduce them. In wiki page-parts you can add more details about it, is more than welcome!!

I think you can find more details in wiki and in gitlab. The major change it is the addition of a resistor in RS-485.

You can use a USB to RS485, take a look at bom.

Your contribution is welcome!


Thanks for the reply @azisi. Much appreciated. I now have the RS485 connection working and have started on the elevation axis. I’ll see how it progresses and then add some thoughts to the wiki pages if appropriate.

On the PCB, V2.2 already has the resistor. It was changes from 2.2 to 2.4 that I could not figure out. I think they are minor and everything is working, so no big deal.

One improvement I have tried to make is with the encoder case. I found it really hard to print because I don’t have an option for support and it has a significant bridge for the top. So I turned it upside down and printed it the other way up. That meant removing the part that inserts into the bracket and extending the spindle on the gear. I’ll write it up as an option or make it available from my gitlab fork of the project.

You can see it here and it was visible in the picture in my first post, working fine for the azimuth axis.