Simple mount for a custom A/B encoder at a windscreen wiper motor. Those motors are cheap and powerful worm gear devices, which can be used for various hacks and projects. By modifying them and attaching a A/B encoder, they can be driven by a H-bridge with a feedback loop and used as servo motor.

This mount fits on cheap wiper motors which can be bought for ~17 € at Autodoc (part number: Ridex 295W0002). It can be fixed to the motor with cable ties. The following modifications to the motor itself are required before it can be used with H-bridge drivers and encoders:

1. The motor cover has to be removed (2 screws).
2. The rotor shaft has to be removed (the carbon brushes have to be retracted and fixed for this).
3. The third asymmetric carbon brush for the second speed has to be removed completely - only the opposing brushes are needed.
4. The carbon brushes have to be rewired to isolate the housing from the negative pin.
5. I have drilled a center hole with a thread into the rotor shaft on a lathe for fixing the encoder wheel. Maybe there are other ways to achieve this (e.g. glueing).
6. The motor cover with the magnets has to be cut or drilled at the end to expose the rotor shaft.
7. All parts have to be reassembled.