> On Dec 2, 2015, at 10:50 AM, Rod Smallwood <rodsmallwoo...@btinternet.com> > wrote: > > Thanks Jay > Yes there's an optical encoder on the other end of the motor. > Depending on the pressure of the roller on the cassette drive wheel it will > deform more or less. > That effectivley changes the diameter and hence the speed. So you need to set > it.
Actually, it's the circumference that matters, not the diameter. Does the circumference of a rubber roll change significantly when you press on it? paul