ROBOTMAK3RS Blog

NXT user Sean Corzine emailed me a picture and description of this nice modification to the 3-Speed Transmission with Clutch project on nxtprograms.com . His design adds the ultrasonic sensor to "see" the gearshift lever to determine which position it is in (high, medium, or low), then he added Math blocks to calculate the resulting output shaft speed based on the input RPM and gear ratio, and modified the NXT display to display output RPM instead of engine RPM. This is a great example of using your available parts and some creativity to solve a problem, and it also reminds me of modern cars -- even in a modern manual transmission, the car's computer is always "watching" what you do in order to try to optimize fuel usage, minimize emmisions, etc. The manual transmission in the new Nissan 370Z even reacts during a shift to blip the engine RPM to match the new gear. Hmm..., anyone want to try adding that to Sean's idea?

Although I've been really busy with FTC ever since the competition got underway, I've still found some time here and there to work on NXT projects. One concept I've always been interested in is the idea of making a certain number of motors able to drive a larger number of mechanisms, one at a time. So I put together a simple transmission design, in which two motors can drive each of four axles, one at a time. The first motor turns a gear which can drive gears on each of four axles. The second motor drives a rack-and-pinion system to move the first motor to across the four axles. The user can press the left and right arrow keys to switch from driving one axle to the next. Here you can see the four axles with black gears on them, and the grey gear on the motor which drives them. Here you can see the rack-and-pinion mechanism for moving the first motor across the four axles. You can see a video of the robot in action below: Although it would probably make a robot more complica...

For you gear heads out there, the latest project on http://www.nxtprograms.com/ is a 3-speed manual shift transmission with a realistic hand-operated clutch, using only parts from the standard NXT set. Build it with the instructions here and try out your driving skills!