For v0.2 of our ground station we have been working on consolidation of our electronics trying to minimize size and upgrade the components. Combined with the current minimized approach for the gear assemblies, this will enable us to deliver a smaller more rigid and reliable ground station.
The electronics that needed to be fitted in are the following:
* An Arduino. We selected Pico for the size advantage
* Two stepper drivers. We are using Pololu compatible A4983 based stepper drivers.
Agis (our electronics expert) designed an integrated board to fit everything in. Here is the result
And the schematic:
We are printing the PCB as we speak and will be posting a new log with the construction and testing.
Despite the fact that NEMA 17 stepper motors were considered our best choice, at the time of our first design some old NEMA 14, spare parts from an old Rep-Rap, where available so we stuck with them. Last week, we received our new motors and did some tests. The first test was to find the optimal torque without overheating the (also new) drivers. Although we have some results, tests will be continued and we will come up with some numbers probably by next week.
Additionally we are working on the new rotator design. We placed the motors on top. This way we managed to decrease the profile of the design a bit and also now the device is a lot more serviceable. Now you don’t need to remove everything if you want to access the motors or the worm gear. We are also trying different designs in order to improve the connection between the stepper shaft and the worm gear.