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  • 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:­teering-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 (­/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.

    3 Attachments

    • SteeringAckermanAngles.png
    • SteeringDavisAnglesAndSlides.png
    • SteeringCombination.png
  • 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.


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