Encoder

I have a winch drum rotating with 3500rpm. I have been thinking about using an old mouse as an encoder, since it is easy to make slots in the end plate of the winch drum. How high speed can a mouse handle, and how is it to interface it into arduino. Or is it other solutions which are better?

Kim

3500? almost 60 Rev's per second? Crankin'!
I think making a no contact sensor that puts out pulses you can measure would be better, or to create an analog voltage that you can analogRead would be better.

You could attach/embed a powerful rare-earth magnet on the rotating part if that is possible and pick up the magnet with a hall effect switch or a solenoid. I heard that is how some car engines control ignition. This way there is no contact.

Most persistence of vision displays use this technique but they're not near your speed, possible less than 10rev/s. Your magnet needs to be bigger but the parts are like $2 total so you may as well give it a try.

So can I use sth like this: http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4639

60rps with a drum diameter of 60mm gives me 11m/s, was thinking about have a pulley on the other end to double the force so the actual winching speed will be 5m/s.

How is it wit reflective tape and sensor in something that is gonna operate outside?

Kim