Im looking into getting two tamiya gear boxes to do 4 wheel drive but im just not sure about the motors that come with these things compared to what im currently using.
Guys, get with the program. The FA-130 size motors used in these are easily replaced, and I've been recommending it for like decades (okay, maybe not decades). I dislike the stock motor, and replace them with this one:
This motor is rated at a nominal 6V, whereas the stock motor is rated at 1.5 to 3V. It has a stall current of 800 mA, about 1/3 that of the stock motor. So you can use it with smaller bridges, like the L293.
You can build the gearbox with any of a number of gear ratios. Choosing the lowest ratio, and using the replacement motors, can strip out the plastic hubs used on the Tamiya track set, so beef it up. Though the gearbox uses plastic gears, when properly kept lubricated it'll last a good while, certainly long enough for the $10 price.
You're not limited to the Pololu motor. Poke around for other size 130 motors, but make sure the shaft length is correct. Remember that Tamiya stuff is made in Japan, the country that institutionalized the use of standard size toy motors. All the Tamiya motor kits used standard size motors.
The motors are extremely easy to replace and Gordon has pointed you to the right place. I have one being used with original motors in a bot for a kid that I teach English to. It is powered by two Lithium ion cells and an L298 h-bridge with BS2 Homework board recieving remote control by IR.
BUT, the pinion gears on these are only a friction fit and will slip. I used a toothpick and a bit of epoxy to secure each one after everything went haywire. I guess the next thing to go is the motors themselves as I am obviously running them excessively hot. But the local hobby stores carry ready replacements - so burn up that first pair before you move on. And keep you eyes open for extra pinion gears.
I have used those gear boxes for little robots and they work great if you replace the motors as Gordon recommends. I also soldered 0.1 uF caps between the + and - tabs at the motor, and between the tabs and the metal housing to clean up the electrical noise a bit.
Comments
http://www.pololu.com/catalog/product/1117
This motor is rated at a nominal 6V, whereas the stock motor is rated at 1.5 to 3V. It has a stall current of 800 mA, about 1/3 that of the stock motor. So you can use it with smaller bridges, like the L293.
You can build the gearbox with any of a number of gear ratios. Choosing the lowest ratio, and using the replacement motors, can strip out the plastic hubs used on the Tamiya track set, so beef it up. Though the gearbox uses plastic gears, when properly kept lubricated it'll last a good while, certainly long enough for the $10 price.
You're not limited to the Pololu motor. Poke around for other size 130 motors, but make sure the shaft length is correct. Remember that Tamiya stuff is made in Japan, the country that institutionalized the use of standard size toy motors. All the Tamiya motor kits used standard size motors.
-- Gordon
BUT, the pinion gears on these are only a friction fit and will slip. I used a toothpick and a bit of epoxy to secure each one after everything went haywire. I guess the next thing to go is the motors themselves as I am obviously running them excessively hot. But the local hobby stores carry ready replacements - so burn up that first pair before you move on. And keep you eyes open for extra pinion gears.