Well, It's May 1, 2006.  The members of the NXT MindStorms Development Program have been 
cleared for public release of their findings and creations.  You will see a lot of very cool 
things pop up over the next few days and months.  Get your minds in gear!

	This was my first creation with the NXT as part of the MindStorms Development Program (MDP).  
Although, it appears to be an NXT Star Wars Hailfire Droid, the plan was something entirely 
different.  The truth is, I like the hoop wheels and wanted to create something "NXT" with 
them while I was stuck in rover making mode.  I feel the hoop wheels provide a very 
“space rover” look together with the NXT elements. 
	The main challenge of building with the hoop wheels is creating a precise NXT drivetrain 
position for proper wheel/gear control.  The hoop wheel‘s inside diameter gear and slot 
configuration made it difficult to render a perfect NXT motor and grapple structure.  But, 
this arrangement is elegant and very efficient.  The NXT brick and chassis can roll over 360 
degrees without falling away from the hoop wheels while maintaining the proper gear mesh.  It 
operates very smoothly and is very robust.  While, the simple structure is strong, my objective 
was to save weight using the least amount of elements possible.
	The NXT HoopRover can easily become a Hailfire Droid.  However, my plan was to create a 
rover with the hoop wheels closer together at the top and a wider stance at the bottom.  This angle 
was inspired by "MurderBall" the documentary film about the evolution of this extreme sport and the 
sportsmen who play full-contact rugby in Mad Max-style wheelchairs - overcoming unimaginable 
obstacles to compete in the Paralympic Games in Athens, Greece.  The very rugged wheelchairs have 
wheels angled outward at the bottom for stability.  I did create the proper angles with studless 
beams for this wheel position but felt that the operation would be impaired somewhat for my rover 
effort.
	I did create an NXT Hailfire Droid version by changing the wheel angle positions on the model 
shown here.  But, to have a more similar Hailfire Droid look...some repositioning of the wheel/slot 
grapple structure, guide wheels, and alignment/drive gears would be needed.
	I am surprised at how well it works.  Resistance and sound within the drive/wheel support 
system is barely evident when operating.  In the future I will add some suspension or flex into the 
design.  In one of the photos you can see two different gears on the motors.  The photo was presented
to show both gear sets that work well.  
	I have included an early design with the hoop wheel.  Here is the NXT MonoWheel.  While it 
works and can drive, it cannot balance. This was a “just for fun model”.  I have been interested in 
monowheel vehicles since I was a kid.

	Thank you for stopping to read about my NXT MindStorms Development Program creation(s).  
Robotics has been a favorite of mine and I hope I have inspired you and other MindStormers to create 
some wonderful NXT marvels.   

Christopher R. Smith
Littlehorn
Official MindStorms Forum Host