775pro encoders

[Andrew Duerner]

Hi everyone,

Ether, here is a screen shot that we took at around 13 or 14 volts.

philso, I don't know if the spikes are from the scope or the encoder. I would have to borrow the scope again to play with more settings.

As for shooter wheel design, from my experiences in 2012, having the wheel be designed to mechanically impart enough energy into the ball can lead to a very accurate shot. Our encoder was used for ensuring that a very accurate rotational velocity was achieved so that the wheel would impart the same energy each time. We added closed loop PID control helped bring the wheel back up to speed in a short amount of time for the next shot. Which in 2012 was important as you could hold 3 balls. This year the cycle times will be much longer.

[Ether]

Originally Posted by Andrew Duerner

Ether, here is a screen shot that we took at around 13 or 14 volts.

Yeah, looks to be spinning about 22000 rpm:

0.0009	seconds per cycle
3	cycles per rev
0.00270	seconds/rev
370.37	revs/sec
22,222	rpm

[GeeTwo]

These certainly aren't the prettiest traces I've seen. However, given that these traces are directly on the motor, teams willing to invest a bit of time and a few cents on tiny capacitors will blow through these rough spots like they don't exist.

[Stephen.Yanczura]

We ordered a few of these and mechanically, they seem to be a very nice solution. Kudos on the design!

@Geetwo -
How would you utilize some baby capacitors to address the issues mentioned? What value and technology caps would I buy and how should I put them in the system? Thanks!

[Ether]

Originally Posted by Ether

Yeah, looks to be spinning about 22000 rpm

BTW, this also shows that there are 3 cycles per rev, aka:

- 3 rising edges per rev on each channel

- 6 edge transitions (rising+falling) per rev on each channel

- 12 edge transitions per rev in quadrature