Option 1 (servos) is almost the cheapest way you can go. The servo has the gear train perfect for a 500 gram robot, it has the drivers for the motor and it has a simple speed control for the driver. The combined value of all that in any other package makes a US $10 servo a steal.
: Hi ppl, : I want to build a small, cheap mobile robot. This is my first one. I : want to use differential drive. I have some problems with the : mechanical system.
: The estimated load of the electronics and sensors is 400 gms. So I : need enough torque to make the robot move. I dropped the idea of using : the motor shafts as wheel as in beam robots.
: The options I have now are : 1) Buy a geared motor or a servo : 2) Use spur gears (devil's configuration) : 3) Worm shaft and worm wheel : 4) Belts : 5) Chains : 6) Make motor shaft drive the wheel by placing shaft on the wheel : perimeter.
: option 1) is too costly for me. option 2) requires me to do some : precision work which I dont think i can. option 3) failed because I : cannot find a proper set here in chennai, India. Option 4) is a : failure because belts slip and have horrible efficiency. 5) The : smallest chains I could find had 3/8 pitch, way too big for me to use : in small robots. So I'm left with option 6) , i.e connecting the motor : shaft to the perimeter of the wheel (rubber tread).
: I do not know if this will provide the kind of torque I require. Can : somebody help me out? I need to know if 6) is alright or if any of the : other options is viable or if there is some other way.
: thanks in advance, : Prashanth Ellina
: P.S : I cannot buy kits because 1) they are too costly for me and 2) I : am from India and shipping will bore a hole through my already bored : wallet ;-)