Bob Built On Bits

Sure does Steve, I've had him free roaming in the living room with collision detection and sonar running but I'm still keen to get him powering up our driveway on Tank tracks. I've tried a few things but I think it's coming down to the bike chains and roller skate combination. Before I start that I need to get a battery that has the amps to power 2 electric screwdrivers I bought for propulsion. Once the motors are powered I can start on the Tracks.

have you checked out the sabertooth controllers.plenty of grunt in them. and a motorbike battery will do for testing.

steve_c

Yeah, they might be the go. I'm getting a 11 volt Lipo off Richie on Wednesday which should give me the 2 x 2 amps I need to get the motors spinning. If that fails then I will go with the sabertooth.

Your robot is great!, Has a great personality, is the closest thing to being alive and it's like watching an X-ray of his belly, I like the video of the robot in action, not all robot builders make a video and it is a shame because is a source of inspiration to other builders. With this type of robot can play much in the dark! How much it took to build it? if you weighed the robot, what is your weight? I have a possible solution for you if you do not want to invest money in saber-toothed traction system for the wheels, I am about to buy two high torque servos and modified for continuous rotation servos and replace damaged so my first Robot the servos are these and is the same model I use for the collar of my robot RSP The servo:

SERVO

Hi R2D2 - This robot cost next to nothing to build apart from DJs Kit ($235.00) Bob is very light weight (not much more than 1 kilo) due to his construction frame (90 degree angle perferated yellow coated tin ) -As I've mentioned before it's the cheap stuff they use to finish off the edges on plaster walls. The stuff is fantastic for building robots, commonly available in Hardware stores and super cheap. I've got the continious servos that came with the kit and presently use them off the L298 H-bridge and they rocket Bob alongon 2 inch diametre wheels at a PW of only 20% off a 14.4 RYIOBI electric drill battery. I love the application of continuous servos for wheel propulsion - they are light and can be very powerfull as you have stated - but have one obvious problem - they have a very short shaft for connectiing to wheel configurations. There is a high stress point at the nylon cog that presses into whatever attachment you want on there. I know there are ways around this but it's just technically annoying. Now the electric screw driver motors and or drills I have a sturdy protruding rod attachment (used to fit in your screw driver or drill attachments) and you can have many combinations for connecting quite large wheels and the shaft can take it. What kills them as a perfect solution is their weight and current. I've discovered the XU1 screw driver motors draw a hefty 2 amps of current through the H-bridge, hence I need a motor bike battery or similar that can deliver what they need. Hopefully Richie has one suitable. The next big step for me is to have this Robot zooming along on some Wall-e type tracks - Tracks that can take him up my steep driveway and through Parks. I've studied just about every D.I.Y track design and they will be the big challenge. All the other stuff is on hold untill my son Austin and I can come up with Bobs legs (tracks) to get around.

Cheers

Okay, you have everything under control, I like that.

HI Hazbot

Have you thought about using big rc truck wheels , the ones with the knobbly tyres.

They will do the off road thing really well.

Chain drive three together , 3 on each side , Has good as tracks.

Steve_C.

Thanks Steve - I'll definately check the truck wheels idea - I have been on the lookout for large toys with tracks on them -