Hi
I'm trying to build a wall avoiding robot with 2 wheels, driven by 2 motors. I already have one motor from my Arduino Starter kit. However, I cannot find its model number. How do I find its rpm or gear ratio so that I can buy an identical one?
Thanks
ThePrince:
I'm trying to build a wall avoiding robot with 2 wheels, driven by 2 motors. I already have one motor from my Arduino Starter kit. However, I cannot find its model number. How do I find its rpm or gear ratio so that I can buy an identical one?
Well - usually there are markings on the end-bell (plastic part where the wires are connected) or on the motor case; generally a model number, maybe a manufacturer's name or symbol. If neither of these exist, or if they do and you can't find the same motor online - then you are pretty much SOL. You'll have to purchase a couple other motors. Such hobby/toy motors are very cheap, though.
That said - even if you did find an identical motor, it likely won't have the same speed - that is, if you hooked up your wheels, etc - via an h-bridge - and drove the robot "forward", likely it would steer to one side or another slightly.
The way you have to overcome that is by incorporating wheel encoders into your design, so you can monitor the transitions of the encoder, calculate the rate, and adjust the PWM of one side or the other to compensate for the speed differences (and, as part of that, you can also use such an encoder to measure how far the wheels have turned, so you know how far you have gone or how many degrees you have turned - it's not very precise in the long run, but it can work well enough for short distances).
There's a label, but I can't make much of it:
"T T Motor"
"2012 11 17"
Do you have a link to the kit showing the motor? If not, maybe just get new motors like below.
I already have one motor from my Arduino Starter kit
The link, picture?
Motor diameter, length?