Quote:
Originally Posted by Ether
Not...speed.
|
I agree with all of the logic presented beyond your initial assumptions, as well as how the 4400 figure agrees better with our measured frisbee speed,
except that we know there was some non-negligible spin down, so it seems to me that 3000 ft/min to 2400 ft/min is not much of a problem. Also,
1) my understanding of our system tells me that the load due to friction
should be constant (once you get going), so a fixed load under increasing voltage will be a decreasing percentage of stall, so you approach 100% of free speed linearly as voltage increase, while the free speed itself increases linearly with voltage (all loose approximations). Under this model I was expecting a positive concavity, which in fact the data has
if
2) you include the origin as a data point (we regularly observe no speed at no voltage)
However, I claim no particular authority in the assumptions about the system I based this on, so if in fact the load increases with speed enough to change concavity, your figure would be more appropriate. Thanks for the explanation.
In any case, for the benefit of others, the 4400 rpm figure Ether has arrived at would give a belt speed of 5200 ft/min and thus an
expected exit speed of 2600 ft/min, compared to our measured 2400 ft/min (+/- 100), showing much less spin down.