I want to be able to know the direction my robot is looking when it’s turned on. I do not want to do a calibration sweep so I have decided to go with an absolute encoder.
https://www.mouser.com/ProductDetail/Om … gKAY_D_BwE
I found a used one for cheap on eBay. So now I need a dc motor with the drive shaft exposed on both sides so I can use a coupling to join them. Since I don’t need fast rpms almost any motor will do. Can someone suggest one? I cannot seem to find a small dc motor with low rpms which has an exposed mating shaft
Brushed DC motors tend to have high RPMs, so you need a gearmotor with a rear shaft extension. Many of those come with quadrature encoders, which you could replace with your absolute encoder. Example: https://www.pololu.com/product/3270
Or, get a gearmotor with a dual shaft gearbox, like this: https://www.ebay.com/itm/6V-DC-160mA-10 … 1525941428
Thank you. This is the motor I have
https://www.openimpulse.com/blog/produc … pm-12-v-2/
You can see the relative encoder attached to the bottom. I am just concerned about taking that encoder off and rendering the motor useless. Clearly there are the 4 leads to the encoder and two to the motor. There don’t seem to be any screws holding the encoder pcb to the motor. Do I just pry it off and hope for the best? I cannot seem to find an ‘exploded’ view diagram so any suggestions would be appreciated before I apply percussive analysis.
It looks like the encoder PCB is held on to the motor by the solder connections to the motor terminals, see arrows on attached photo.
You will have to unsolder those cleanly in order to safely remove the PCB, after pulling off the magnet (best to use a micro-sized gear puller). Otherwise you will probably destroy the brush connections.
You realize, of course, that the encoder will report the motor shaft position, not the output shaft position, so you will have to keep track of shaft revolutions to track the head position.