• 3D Printing really large gears

    Timo Birnschein • 11/06/2019 at 02:41 • 0 comments

    I am in the experimentation stage. I have all the hardware together and just want to see this go.

    My current plan of record is the implementation of everything on my Dinghy instead of an RC boat. All I need is a very large servo motor (old windscreen wiper motor with an off the shelve H-bridge, a 10 turn potentiometer and an old disassembled servo as a controller) and some very large gears that I can mount to my existing steering wheel. This will also allow me to remove the servo from the steering wheel and go back to manual if I have to.

    I started by designing the gears, laser cutting them in under a minute and testing the prototype on the steering wheel. After I was reasonably certain this all would fit together nicely, I sliced the large gear into four pieces and started printing.

    My first gear had 90 teeth and wasn't big enough to fit with the servo gear. I would have needed to cut a hole into my console which I really wanted to avoid due to the prototypcal nature of the project. So I made a bigger one with 120 teeth:

    This one can be mounted up higher than the other one. Here a comparison:

    This would be the largest single part I ever printed (fully assembled).... so I went for it with a pretty empty filament spool.

    Part one done:

    Part two done!

    Part three and four will follow the next couple days. This already looks quite amazing and the teeth are super strong. I print this in PETG with 33% infill and 3.5 perimeters (alternating three and four perimeters for better strength and better infill to perimeter adhesion).

  • Windscreen Wiper Motor to RC Servo Conversion Parts

    Timo Birnschein • 09/25/2019 at 04:34 • 0 comments

    5k potentiometer with 10 turns lock to lock for finer control: https://www.ebay.com/itm/183437985171

    High current h-bridge to drive windscreen wiper motor directly from an RC servo motor control board which is then connected to the 5k 10 turn potentiometer: https://www.ebay.com/itm/Double-BTS7960B-DC-43A-Stepper-Motors-Driver-H-Bridge-PWM-For-Arduino-Smart-RCB9/193093897725?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

    Details regarding the circuit can be found here:

    http://www.hessmer.org/blog/2013/12/28/ibt-2-h-bridge-with-arduino/

    and here: 

    (not my video)

  • Frame Class = 2 equals boat

    Timo Birnschein • 09/25/2019 at 01:45 • 0 comments

    Right after the installation of the latest firmware, I needed to change the FRAME_CLASS to 2 to select that this controller will be used in a boat: