Let's Make Robots!

Omniwheel Growbot with Flexable Body addition

Navigate with eventual R/C and infrared control
Weather_strip_on_Servo_Motor.jpg899.38 KB
Flex_Body_top_with_Processor_board.jpg342.69 KB
Omniwheel_to_Servo_detail.jpg261.47 KB
Flex_Body_bottom_view.jpg313.67 KB
Omniwheel_Growbot.Original_Prototype.jpg303.46 KB

 Here is the new addition to my Omniwheel Growbot. I constructed a body using 2 peices of plexaglass and sandwitched the servos inside. I used a peice of weather stripping on the top of the servo to resctict movement. It is easy to change angles and motor placements. It worked a little better then the circuit board prototype but still far from perfect. I tried on several types of floors. Wood panel, light carpet and concrete. I also changed the wheels to single wheels instead of double wheels. A little better. Then I increased the wheel base. A little better. I think I am as far as i can go with hard plastic wheels. They have no traction at all even in smooth surfaces. Sort of like driving a car on ice. I suggest anyone thinking about omniwheels, should forget about hard plastic wheels. Totally useless. Silicone coated or rubber seem to be the only way to go. I plan on trying the 3 wheel setup as a last atempt. The body is very easy to add or subtract and position servo motors as desired. Can always go back to regular wheels. lol  Included are some pics and waiting for the videos to be approved. A picture speaks 1,000 words and you will soon see what I mean. It has been a learning experience for sure. Waiting of a stable robot before I start the programming. It now runs on a 10 direction subroutine.


Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
looking good! the wheels could be closer to the chassis though

efficiant test platform. 

Simplicity makes the world go around 

  I can move the wheels in and out easily by changing around spacers, but found by trial and error that the longer wheel base works best so far. Videos should be done later. As I said, I am getting ready to scrap the hard plastic wheels if the 3 wheel system isn't any better. Found you need all 4 motors to be running doing something. They can't pull dead weight wheels very well. Buyer beware, stay away fron hard plastic wheels for robots (personal experience). It is all traction problems for now. I am not going to get lost in programming until I have a sound robot. At least it can be easily changed back to a simple two wheel Boe Bot configuration hence the special body design.

Does the stamp thingy have inbuilt routines for driving the servos?

I've tried continuous rotation servos on my threewheel omniwheeler. The problem in doing it with three wheels is you need really fine speed control. I could not, for the life of me, get the servos to go at an appreciable resolution of different speeds.

If it's any help, I have also decided that hard rollers are a dead loss! I'm going to try coating my rollers in liquid latex as a last resort.

Yes basic stamp has subroutines for now and can be finely tuned, but seems alot of trouble. Waiting for some sales before I invest on some better wheels. Somehow I have to make my hobby pay for itself or wifey would freak out. Dead loss on the hard plastic wheels is an understatement for sure.
Looks pretty, bird (lol)! Can't wait till you finish this monster :)