Powerful Dual Motor for Legos

One thing that often seems to be a gotcha in building complex drive systems with Legos is that the motors lack power. (The new Power Function XL motor looks to be available only in the Bulldozer kit.) So i decided to see what I could build for cheap. I found a suitable motor on the Sparkfun sight for about 10 bucks and ordered it. The Tamiya kit features dual motors (that function independently) and seems to be about the right amount of power for my Lego needs. The only downside is that it isn't a perfect mate for the Lego system. The purpose of this Instructable is to show one way to adapt it for use in Legos construction. Caution: More powerful motors draw more current and may not work with Robotics controllers.

Step 1 What you'll need

Here's the Lego parts we'll use. Shown are the 3749 Axel Pin and the 6536 Axel Joiner Perpendicular. Pick a suitable mounting plate as well. As you can see, the one I used is 6 x 8. One motor has already been modified; I'll go through the modification of the other motor in this instructable.

Parts list:
Tamiya Twin-Motor Gearbox kit, Item 70097. Includes the mounting bolts. Available from Sparkfun.com.
6x8 Lego Plate.
3749 Axel Pin
6536 Axel Joiner Perpendicular
Lego Electrical Connector Cable
Epoxy (I used JB Weld – regular, not quick setting.)
Lacquer thinner to clean parts before gluing. (I usually do this to remove mold release, oils, etc. However: Caution: Do this outside! Lacquer thinner is *extremely* flammable.)
ABS, PVC, & CPVC pipe cement. (This was suggested on several web sites to glue the Legos. Caution: Do this outside! The pipe cement is *extremely* flammable!)

Comments

[Chowmix12]

i hake this gearbox but output is uneven.. how do i fix this?

[mage]

if you can fit it in your lego model, try to put a power relay in there to so that the robotics controller just has to activate the relay. then you can have any power of motor on your creations as you want as long as you had a sufficiently powerful secondary power supply

[shooby]

Awesome, nice job. So the motor kit came with that dark green housing right?

[doctek]

Motor kit includes both motors, the housing, and all the gears. Even has some gear lube in it.

[killerjackalope]

What you really need is the old train sets, I had one that got a little out of hand, big 12v transformer, I read the 12v and being young decided to hook it up to a car battery charger, which slowly increases current as it goes. The trains gained insane speeds and only the best balanced ones remained, suddenly one of them went across the switch things and there was flash as it left the track at full speed and hit a fairly sturdy lego structure, obliterating it, damn that was cool, I grew up and started doing that with big stuff... Forklift racing...

[PineapplebobTheGreat]

Now you need to show us how to do this with knex.