Stepper motor and axis movement should be accelerated, decelerated and smooth. This is important for a variety of reasons including less strain on the axis and the gears, plus inertia compensation.
Agis with Manthos spend some time looking into some options and finally agreed to implement acceleration resulting to smooth tracking using an Arduino Library and amending it a bit. The results is pure awesomeness for our tracker:
This code and implementation goes straight in our v2 design. Code can be found in our repository.
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.