I assume the wheel motor drivers are (ti?) DRV8833 Dual H-Bridge Motor Drivers.
With steering geometry I meant the following the different angles of the front wheels when in a curve... see attached pic... (and, for example, this link: https://gearcraft.blogspot.com/2011/11/steering-car.html). Ackerman (trapez) is geometrically better than just parallelogram. Davis is geometrically perfect but much more complicated to implement and has wear issues compared to the simply to implement Acherman setup (https://www.slideshare.net/jeetamrutiya1/steering-gear-mechanisms-kinematics-of-machines). The wear over time of the slides G, E, F and H demises the accuracy. Some current cars us a combination of slide (rack and pinion 'sliding' in E and F) connected with two link bars to the fixed-length and fix-angled levers (includes space saving), which could work nicely with your setup of the slider on the screw with driven by the micro servo.
Honestly I wasnt even aware of this. Its great thing to learn about. I guess my implementation is just parallel.
If I get it right it would be enough to just move the rotation points on the T bar toward the middle. The problem with that would be that right now the T bar slides with the plastic screw on the stepper. If T bar gets tilted then it would get stuck?
Thanks for pointing that out. Thats interesting problem. I didnt send out the gerbers for fabrication yet.
As for the drivers I used TI drv8830 drivers for old implementation. This time I will go for LB1930 as they seem cheaper and more widely used for hobby stuff. They are used for one of espruino tutorials I think.
© Espruino, powered by microcosm.
Report a problem