3 ms·
From the comments: Use a twine, interleave it around the blades and let it run for a second or two. With a long enough twine, the number of knots divided by the
by rohanprabhu 12y ago
From the comments: Use a twine, interleave it around the blades and let it run for a second or two. With a long enough twine, the number of knots divided by the number of seconds gives you the RPS :) Like the thought, but at around 380 RPS, I don't think I will find a twine long enough.. plus the twine will offer a very high resistance to the blade after only a few knots..
- retSava 12y agoBut we won't know how long time it takes to wind up to constant speed and without running for a while this will attribute to a fairly large error. From the audacity FFT plots we see that it takes a fairly long time (100's of ms) to get to the target speed (ie the rise time of a step response).