High speed encoder with slotted / flat end... can't find one.

[artdutra04]

What kind of ± resolution on the RPM are you looking to achieve? And at what frequency do you want to know the current RPM of the shooter?

I would suggest creating an Excel document to calculate how various changes to the CPR and sampling time interval affect the resolution of the shooter speed output. Depending on what you are looking for, you may be able to achieve your desired results without hardware changes.

For example, with a 128 CPR encoder (and 1x decoding) sampling over a 100ms time interval, you can achieve an RPM resolution of 4.6875rpm per encoder count, while sampling over only a 30ms window yields a resolution of 15.625rpm per encoder count.