EagleTree RPM sensors

[Motions]

I want to get an RPM sensor for my Micro logger. I'm using this on large electric helis and want to know which sensor you guys have found to be the best and easiest to use. I want it to be easily removable so I can use it on several models.

What's your opinion... new brushless motor sensor or the optical sensor.
No hall effect.

[gin]

I just received my Eagle Tree MicroPower data logger yesterday. I went with the brushless rpm sensor and just logged my first flight (short flight, very windy today and the TRex 450 was getting tossed around a bit). It worked great. One wire hookup from the rpm sensor to any of the three motor leads. There are two wires on the sensor, the instructions say you should only need one of them.

[Motions]

I'm leaning towards the brushless sensor but don't like the extra module and wires. How is the "head speed" calculated for helicopters or gear boxes? The sensor is measuring motor RPM so does the software have a ratio you enter to get actual head speed?

[Gus]

Motions,
You specify when you set it up. Setup asks for the number of Poles(Magnets) and the Gear Ratio.

If you don't have two motors to monitor, just twist the two wires together and plug them into one of the BL Motor wires.

I put a female plug on one of the motor wires one each of the models that I may want to monitor. That makes it easy to move the sensor and Micropower between planes. In fact I just velcro the sensors to the esc on the bird that I want to monitor.
Gus...

[Motions]

Thanks Gus. Eagle Tree just replied and said the same thing.

So do you actually solder a plug to one of the motor connectors or is the wire small enough to "slip into" the bullet connector?

[Gus]

Motions,
I actually use a small bullet connector set, I solder a short piece of wire to the female connector, cut a short piece of insolation off of the motor wire between the motor wire bullet connector and the motor. I then solder the new bullet connector to the motor wire and put heat shrink over the exposed metal of the solder connection and the small bullet connector.

I shorten the leads from the RPM sensor to the max length that I wll need (Normally less than 6 inches). I solder both RPM sensor leads to the small male bullet connector.

I repeat step 1 for each bird that I will be using the RPM sensor on.

if you send me an PM with your e-mail address, I will send you pictures of my setup.
Gus...