Should I use a potentiometer or Quadrotor encoder?

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Jarfi
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Specifications:
Measuring angle from -90 to + 90 degs.
Low friction
Low moment of inertia
Requires high speed
Accuracy about 1° degree.
Needs to be durable, handle mechanical vibration

I use a dc motor as an actuator, this is a custom built servo. This is a very small device, and the encoder must be low in weight, just several grams

Main problems:
Potentiometer: Noise, high friction
Simple ADC reading, no programming required nor are there any interrupts

Quadrotor encoder:
High CPR encoders are typically made for large motors, too big and clunky. They are also more complicated as they include interrupts
No friction, no noise

What should I generally go for, what are people using in servomotors for small but accurate robotics

I'm having trouble finding either, that fit the space requirements and accuracy requirements(at least 360 CPR)
 
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Avoid a resistive pot if possible. Do you need to know where zero is ?
A rotary encoder with an optical disk will probably be your best minature low mass integral solution.
An example would be the AVAGO; HEDS-9040#J00 with an optical code disk.
http://www.mouser.com/ds/2/678/V02-1132EN_DS_HEDS-9x40_2014-03-170-1130980.pdf

Start here to see an example of possibilities: https://au.rs-online.com/web/p/rotary-encoders/7967874/
Essential accessories show optical code disks, with through holes, that will mount directly on a shaft.

https://www.ebay.com.au/itm/HEDS-9040-J00-Optical-Incremental-Encoder-30000rpm-Digital-2000-Count-Multi-Qty/302531789915?hash=item46704cc45b:m:mDIJZ1jmIVQhLHIYKJaX6ww
 
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Baluncore said:
Avoid a resistive pot if possible. Do you need to know where zero is ?
A rotary encoder with an optical disk will probably be your best minature low mass integral solution.
An example would be the AVAGO; HEDS-9040#J00 with an optical code disk.
http://www.mouser.com/ds/2/678/V02-1132EN_DS_HEDS-9x40_2014-03-170-1130980.pdf

Start here to see an example of possibilities: https://au.rs-online.com/web/p/rotary-encoders/7967874/
Essential accessories show optical code disks, with through holes, that will mount directly on a shaft.

https://www.ebay.com.au/itm/HEDS-9040-J00-Optical-Incremental-Encoder-30000rpm-Digital-2000-Count-Multi-Qty/302531789915?hash=item46704cc45b:m:mDIJZ1jmIVQhLHIYKJaX6ww
Thanks.

I've been weary of resistive pots, its simply that they are ubiquitous.

I do need a zero location, however I use a simple calibration on startup methods, where the motor drives the mechanism to a certain start point, all the way to the end, where a switch might be located. So an absolute sensor is not required. Dead reckoning is enough.
 
Jarfi said:
I do need a zero location, however I use a simple calibration on startup methods, where the motor drives the mechanism to a certain start point, all the way to the end, where a switch might be located.
You do not need the switch with the HEDS-9040/9140 series, since it has three channels, two are phases in quadrature, the other gives one index pulse per revolution.