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

[Tom Line]

We've got fairly tight requirements. In order to improve our shooter, we're increasing the number of counts our encoder returns.

Right now we have a bourns 128 count with 1/4 slotted shaft input.

What we're looking for is a 512 count with 1/4 slotted shaft input at reasonable cost.

With 128 counts per revolution, we see around 7000 counts per second. 512 gets up to 28,000 or so per second. My understanding is that 40,000 per second is the cRio's limit, so I'm happy getting to 3/4 of it. Also note that the encoder will have to be fairly robust to handle the speeds (3000 rpm+) that our shooter runs.

We've looked but can't find something in stock that meets these requirements. Does anyone else have an off-the-shelf idea?

I understand we could gear the encoder we have now upwards to get the appropriate counts, but we direct drive the encoder to minimize noise and would like to stay that way. We don't have the ability for a drop-over or code wheel style encoder due to mounting real-estate.