OPTICAL TACHOMETER KIT: This kit measures RPM of propeller shafts etc. without physical contact. Similar to the kit published in Silicon Chip magazine May 1988, but includes a crystal controlled calibrator. Use a Digital Multimeter on 200mV or a 3.5 digit panel meter as the display. Kit includes PCB and all on-board components.
That optical sensor kit looks like what i've been looking for, includes all the major parts, all i have to do is provide a multimeter? Have you any personal expirence with this kit? I think this is what i'll end up with. Simplest solution to my problem of measuring rpm. If i can't find anything homemade i'm gunna probally order this.