Clamp on timing belt pully or other mid-shaft encoding method?
Clamp on timing belt pully or other mid-shaft encoding method?
(OP)
I need to put an encoder mid-shaft on some old equipment we are retrofitting. We can't put anything at the end of the shaft. The shaft is about 1 3/4" Dia.
Is there such a thing as a clamp-on timing belt pulley that we can put on without having to dismantle the machine?
I have very vague recollection about reading about a company making a shaft encoder that sensed the shaft position mid-shaft. But at the time I wasn't really involved, so am uncertain if I actually understood was it was.
A few more details if you are interested. A continuously rotating shaft, about 5 RPM. We need absolute position or angular measurement of 1 rotation, approx .1 deg precision.
Thank You,
Joe Dunfee
Is there such a thing as a clamp-on timing belt pulley that we can put on without having to dismantle the machine?
I have very vague recollection about reading about a company making a shaft encoder that sensed the shaft position mid-shaft. But at the time I wasn't really involved, so am uncertain if I actually understood was it was.
A few more details if you are interested. A continuously rotating shaft, about 5 RPM. We need absolute position or angular measurement of 1 rotation, approx .1 deg precision.
Thank You,
Joe Dunfee





RE: Clamp on timing belt pully or other mid-shaft encoding method?
What sort of stuff do you have on the shaft already?
You can get a gear tooth sensor, which ought to detect existing gears and sprockets, especially if they are steel. You would need some feature to provide an index pulse.
JHG
RE: Clamp on timing belt pully or other mid-shaft encoding method?
Joe Dunfee
RE: Clamp on timing belt pully or other mid-shaft encoding method?
I think in order to get absolute position in 0.1° precision you will need a hollow shaft encoder.
ISZ
RE: Clamp on timing belt pully or other mid-shaft encoding method?
But, I did find the term I needed to figure out for a clamp-on gear or sprocket. In the industry, it is known as a "split gear" or a "split sprocket". We will go with a split gear that we will clamp onto the shaft. A mating gear will be attached to the encoder.
I found a custom gear maker who has done this, but we may just purchase a pair of finished gears, and cut it ourselves. (the two are needed because, of course, we can't cut something in half and not loose material - the curf.)
Thanks for the input.
Joe Dunfee
RE: Clamp on timing belt pully or other mid-shaft encoding method?
FWIW. If it fits with minor modification, it might save you some time and $$$.
Griffy
RE: Clamp on timing belt pully or other mid-shaft encoding method?
So, no split gear is going to be needed.
The next challenge is that this part of the shaft seems to have a redundant bearing and collar added, that we would like to take off to make more room for our stuff. But, the mystery is what is inside this undocumented gear box that is next to it... what is really inside? Are these apparently redundant parts REALLY redundant?
There are definitely some challenges to upgrading old equipment. But, it is also nice to work on old stuff. You see things you don't see on new equipment. Since we machine a lot of 1/2" plate in a CNC machine, we can make the items any shape we want. So I am inspired to make the brackets with some ornamental curves in them.
Joe Dunfee
RE: Clamp on timing belt pully or other mid-shaft encoding method?
Ted