Optical Tachometer

[DaveT1]

Has anyone used an inexpensive optical tachometer to check to see if all of the motors are running uniformly?

http://www.amazon.com/CyberTech-Digital ... tachometer

 

[Driffill]

You don't want the motors running uniformly.

It wouldn't be able to manoeuvre or compensate for wind etc if the speeds were locked together. That's why there is four separate ESCs

 

[tanasit]

You don't want the motors running uniformly.

It wouldn't be able to manoeuvre or compensate for wind etc if the speeds were locked together. That's why there is four separate ESCs

Agreed the key of the multi-rotor control is the proper varying speed of each motor, plus that Tachometer requires the reflective tape on the spinning object to be measured.
Thus not suitable for our Phantom because the tape weight which is suitable for large spinning lathe or big motors.

For helicopter and airplane rc, we use the light sensor tachometer which detects the light that pass through the spinning blades, so most of them have the selector switch for 2,3 or 4 blades.

 

[DaveT1]

I understand that the motors have to run at different speeds to maneuver, my thought was use the tach at idle speeds to see if all of the motors were close to the same RPM. Thought this might be an indicator for potential motor or bearing problems.

 

[npalen]

I've used one of the inexpensive tachs for comparing the idle and full speed RPM of the motors on an earlier Phantom. This has been two or three years ago and don't remember the results. No problem to attach the reflective tape.

 

[Ramphex]

There's a video guide of a guy doing this test with the stickers. I personally haven't used one.