ARGO 6x6 XTV

Here's another update, picking up from where I left off. After lots of experimenting it was clear the Micromotor was not up to the task of steering. Its a great little motor that was able to lock the brakes when paired with the small servo actuator. But its low rotational velocity meant that it took an ice age to twist the handlebars to lock and you'd miss your turn every time.

The Power Functions Servo Motor was my last resort. I was concerned it would be too large, but in the end it worked out beautifully. The servo's 180 degree rotation worked perfectly with the 12 tooth pinion and small gear-rack. The rack and pinion assembly is compact and the modular design allows you to quickly drop the servo unit in or out depending on how you want to interact with the ARGO. Twisting the handlebars activates the brakes via the flex cables. The servo unit allows you to do the twisting remotely.

You can see how the disk brakes work, and the rather surprising LEGO part that made it possible to generate high-torque braking needed by the ARGO. Try making some disk brake equipped Technic creations of your own. Well, this is probably the last update for the ARGO, so if you like it, please vote. Let's put Technic front and center. Thanks everyone!

Andrew

Thanks to everyone for their great feedback and encouragement. Some of you asked for radio control, which I didn't think was possible due to the small size of the ARGO relative to the size of available Technic motors. But it was a cool challenge and I gave it a shot. The LEGO Micromotor was the only thing that would fit, but its limited torque and low RPM posed serious hurdles.

I tried two methods to servo the handlebars; the first method is belt driven, and the second method uses the small Technic linear actuator. I prefer the belt driven method because you still have the option to manually turn the handlebars yourself. Unfortunately I couldn't get the belt driven method to produce enough torque to lock the brakes, too bad.

The second method uses the small Technic servo actuator directly coupled to the handlebars. While this means the handlebars can't be turned manually, this method produces sufficient force to lock the disk brakes. I hope you like it! Tell me what you think.