Fastest LEGO Technic Car!

[aeh5040]

On the issue of speed measurement, my experience with about 5 different GPS devices over the years is that for maximum speed measurement it is hopelessly unreliable.  For example, according to GPS I fairly regularly achieve speeds of over 80km/h on a pedal bicycle, and 200km/h in a car.  There are good reasons for this - GPS works by measuring position, using a method that is accurate to a few 10s of metres at best.  If two consecutive position measurements are off in difference directions (say 10m and 60m instead of 20m and 40m), the calculated speed will be a long way off.  On the other hand, average speed measurements over a long distance should be better.

While I haven't experimented much with the Lego speedometer, one would expect that the underlying technology (rotation counting) would provide a much more accurate method of speed measurement.

[Marxpek]

Get a better gps device then, my bryton rider 100e is very accurate in 1 second measurement mode, i never get weird measurements and all all graphs show perfect parabolic curves (and the graphs also include the speed measurements), i see no reason not to trust it.

And measuring by rpm is not accurate, especially with high rpm on the lego speed computer; shave 0.1mm off the tire and it shows higher speeds then you are actually going.

[Sariel]

20 minutes ago, Marxpek said:

And measuring by rpm is not accurate, especially with high rpm on the lego speed computer; shave 0.1mm off the tire and it shows higher speeds then you are actually going.

True. Not to mention that it measures how fast your wheels are rotating, not how fast you're going, and that's not the same thing. Spin your wheels up in the air and the speed computer will tell you you're going super fast.

[mwnilsson]

@Marxpek No havent done any more design improvment. Maybye later...  Dident know they have internal resistors!  dont know about lego led.