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Topic: Project advice for hacking an old RC car... (Read 192 times) previous topic - next topic

moses1592

This is a bit off topic and not directly related to Arduino (although an Arduino may prove to be a solution) but I need some electronics help with a small (silly) project I'm working on. On a whim I bought an old beat up toy-grade rc car at a garage sale. Purchased it simply because it looked cool and only set me back $10. As stated it is toy-grade with non-proportional steering (no servo, just a motor and gearbox to turn the front wheels) and non-proportional acceleration. I have some old ESC's and 2.4ghz tx/rx sets lying around from previous projects and would like to hack the car and put hobby-grade electronics inside.

That being said, here's my dilemma... There is virtually no way to put a servo in this car given the way the plastic is molded. I am ok with this and I do not care if it has proportional steering (proportional acceleration, 2.4ghz, and ability to use a small lipo are my only goals here). So, does anybody have any advice for how I can somehow connect the steering motor to, say, a disassembled servo, for example, such that I can control its direction with my receiver? All it needs to do is simply turn the motor on CW, reverse voltage for CCW, and turn it off in relation to the position of the steering wheel on the transmitter. Any ideas?

I almost got it to work by gutting a servo, removing the servo motor and gears, connecting the rc cars steering motor to the servo board and adjusting the servo pot to middle position. When I say it "almost" worked is because the forward and reverse voltage turns the motor perfectly, only problem is there is no way to calibrate the trim closely enough to keep the motor OFF when the steering wheel is at zero position. Even the tiniest offset will make the motor start spinning.

Anybody have any advice for a simple way to achieve this? Perhaps there is a way to build upon what I attempted by somehow increasing the zero range before the motor spins? Or sticking an Arduino in there somewhere. I am open to any ideas!

Unfortunately, since there are many space restrictions, I would recommend you to buy a new car such as a Cheapo Rock Crawler with tons of space for electronics.

Then, you can take it apart and install an Arduino along with bluetooth/wifi module, servos, rx, etc.

The motor in this car won't be able to last long on even the smallest of Li-Po's or Li-ion's.

TonyWilk

#2
Dec 10, 2017, 10:31 am Last Edit: Dec 10, 2017, 10:39 am by TonyWilk
I almost got it to work by gutting a servo, removing the servo motor and gears, connecting the rc cars steering motor to the servo board and adjusting the servo pot to middle position. When I say it "almost" worked is because the forward and reverse voltage turns the motor perfectly, only problem is there is no way to calibrate the trim closely enough to keep the motor OFF when the steering wheel is at zero position. Even the tiniest offset will make the motor start spinning.
I know this is long ago, but... You could try putting the servo back together and wire the steering motor across the servo motor.

If you are lucky, the time the servo takes to to more to one end (and then stop) will be enough to drive the steering motor one way, and the same back the other way.

Yours,
  TonyWilk
 

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