My first Robot- basic drive system

This is my first project so far. I have got the basic forward system almost working, and was wondering if anybody had any tips/improvements? It runs straight and I have made the treads tighter to get more force from the wheels, and it turns fine.. got some pics, just done quickly from my phone.

I think that with everything from only 3 AA batteries, the motors are not getting the power they should. I may connect some kind of rechargable power pack as well. the treads are coated in correction fluid to reduce friction a bit. I also found that an LED can be run from the output pins using the motor driver, allowing lights that are on/off depending on the direction of the robot.

The next step

I will probably add a SRF(04, 05 or 08) with a servo, and may add a laser diode for some cool effects.

drives

  • Actuators / output devices: 2 MFA multiratio gearboxes with RE140 motors
  • CPU: Picaxe 28x1
  • Operating system: Picaxe 28x1
  • Sensors / input devices: none so far

This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/my-first-robot-basic-drive-system

I think your tracks are too

I think your tracks are too loose.

Nice paint job :smiley:

does having loose tracks

does having loose tracks make much difference, particularly to the turning?

I will probably change the box sometime soon for a CNC cut custom base. The advantages of being in school…

Well… if your wheels are
Well… if your wheels are spinning, and I can see the tracks are dangling…

Easy Way, Hard Way

Hmmm… Fritsy’s right. If the wheels are turning but not the tracks, then the tracks aren’t tight enough. In fact, I can see from your second photo that the track is floppy. Much too loose.

When you try to turn the vehicle, do the motors turn, or do they sound like they’re stressing? If the motors aren’t turning, then you need more powerful motors, or supply more power to the existing ones. My tank is about the same width as yours and it works fine anywhere except carpet. I’m only using servos as teh motors, so you should have lots more power than me for turning.

If you find these motors are underpowered or you’re stuck with them, another option is to make the whole chassis much wider. Make it about twice as wide as it is long and that should make turning a lot easier.

Your wheels look like smooth
Your wheels look like smooth plastic. They won’t grip much. I would put a rubber band around them or maybe a thin layer of hot glue to give them better traction on the tracks.

Nogo. I know the wheels and

Nogo. I know the wheels and the treads, they work perfectly fine togther as they are. It is only a matter of having the bands tight enough, and not too tight. (I need a word for the middle alternative :slight_smile:

- And as said, Tape on the tracks makes it much easier to turn.

Most servos should have mor
Most servos should have mor torque than a standard motor/gearbox set unless you’re using micro or sub-micro servos.

Where did you get those
Where did you get those plastic motor housings?

gearboxes

the motors, gears and plastic plates come as a multiratio gearbox made by MFA. I got them from here, http://www.anticsonline.co.uk/ , they don’t have any on their site, I got some pre-assembled from my local store (cardiff) . I believe techsupplies sell something similar.

done.
re-made it today using a gluegun instead of foam tape. much more solid and the tracks are firm. It turns fine. Also made a bumper to hide the front gearbox.

I like to followup old

I like to followup old threads so here it is: this would make a great flower planter that could follow and position a plant in the sun. Cool.