LBD (Little Black Duck) gear motor and wheel kit from Dagu is a tiny drive system for little robots. Used in the Doodle Bot kit it is also available in a pack of two motors + two wheels.

What’s in the box

WP_20130327_004

The two servo looking things are the LBD gear motors. These are essentially servos without a limit stop and without the control circuit. ie, they are not servo’s even though they look like it. The giveaway is there are only two wires in the lead for +ve, –ve but no PWM signal wire.

All the servo horns are included for both LDB motors. The only one needed is the circular one for fitting the wheels to the motors. I’m not sure what the others would be used for since these are motors not servos. Perhaps it is just as easy to include all of them. Also in there is a packet of screws for fixing the wheels to the servo hubs.

Two wheels are included which are nice clear laser cut disks with removable rubber treads. One is shown here with the tyre removed. It is just thin rubber but quite grippy and not plastic.

WP_20130327_007

Putting It Together

Assembly is a pretty quick job. You will need a little Phillips head screwdriver about #0 size. A pocket knife may do in a pinch. The only thing to note is to use the centre hole in the group of 3 on the round servo horn for each of the 4 screws. Things just don’t line up otherwise. The hole is shown below pointed to by the screwdriver…

WP_20130327_012

Four of the screws with the washer like head in each wheel and you get them assembled like this:

WP_20130327_013

Then its onto the LBD motors with the really little screw in the middle and your done.

WP_20130327_015

Start Me Up

To test the LBD gear motor and wheel I’ve used a Micro Magician V2 controller. These has built in motor drivers so its super easy to get things going.

Add some batteries and a little bit of code and presto!

WP_20130327_016

Test Drive #1

I put a bit of tape on one of the wheels so you can see the revs when they ramp up to full speed. The Micro Magician is running a slightly modified version of Dagu’s sample code for the motors. The motors sound a little noisy but they aren’t as bad as it appears in the video rather about the same as any servo when it moves.

Test Drive #2

This video is from Dagu showing the LBD’s powering a Doodle Bot