which rpm sensor? (eagle tree)

[eightythree]

hey guys, i was just reading through a thread about tachs and realized, i dont have one! well i have a little point and push a button deal (made for planks, but tach bcp, trex450, etc). i was considering a sky tach but id rather have a data logger if i can read rpm and other perameters. so which sensor would be most accurate? or which is prefered?? i see sensors for brushless motors you connect inline, hall effects sensor, and an optical sensor... which works best for reading blade rpms? thanks!

[catfight]

eightythree,

I use the optical sensor on my T600 and the Magnetic (Hall) on the T450 - prefer the magnetic because you just ream out one of the grub screw holes and CA magnetic in there then "Shoo Glue" sensor to the frame - simple. I don't like messing with the battery wires or adding connectors.

[alwallash]

I have used the optical and brushless motor sensors.
I could not get a solid reading with the optical.

I switched to the brushless motor sensor on all my helis.
It is easy to solder the single wire to one of motor wires on the ESC connectors.
RPM readings are steady and troublefree.
In the software, you just need to tell it the # of poles in the motor.

I really like brushless motor sensor for EagleTree.
Al

[eightythree]

thanks for the replies. when i purchase a datalogger i'll probably buy a couple different sensors.

alwallash- so how do you figure blade rpm after getting motor rpms?

[Dynamic]

When you configure your model in the software it will ask you how many poles your motor is. This allows it to correctly figure out motor RPM from the motor wires. Right beneath that when configuring your model it will ask you for your gear ratio (varies depending on your pinion obviously), once it knows the rpm of the motor and the gear ratio it can calculate the headspeed of your bird.

[eightythree]

cool, thanks guys! i like the easy way out.. math mixes my brains up.

[Mercuriell]

YOu don't have to solder anything - just one small diameter wire from the brushless sensor easy to just push into a motor/esc plug and put together - works well.

[bullaculla]

Thats what I do. I just stick it in between a bullet connector and shove them together. Plus, I usually only use the eagle tree for testing new setups. I dont think i'd fly with it on all the time.

[Mercuriell]

Originally Posted by bullaculla

Plus, I usually only use the eagle tree for testing new setups. I dont think i'd fly with it on all the time.

I've gone to leaving them permanently in line on my 600s (Logo and TREX) - useful for post mortem analysis and also with the LCD display saves the embarassment of inadvertently trying to fly on an empty pack !

[Dynamic]

What I do is I solder the 2 wires to the end of 2 needles and cut off the excess leaving a 1cm needle on the end of the wire. Then I stab them into my ESC wires. They can be removed if needed and the hole it makes is not large enough to cause problems (hardly noticable). This lets me switch models easilly if needed. Unless I'm using for a specific purpose though I leave it on my 600.

This lets me save every flight log so I can see the progression of my batteries. I addition if anything weird happens you can cleary see if its a power issue. The weight is insignificant.

In addition as I have the power panel mounted on my bird I can verify that my battery is at full voltage before I fly as a safety double check.

[eightythree]

id probably leave it on the 600 as my 450s i just play by ear sort of thing. but using a needle makes for easy changes.. thanks for the tip!

where do you guys purchase eagle tree products..? i havent looked around much and would like the best prices if possible. thanks again for all of the replies!

[catfight]

83,

http://www.readyheli.com/category_s/148.htm

I don't know of any price breaks anywhere but Readyheli is tops and has in stock 0)

[Dynamic]

HDX has them
http://www.helidirect.com/index.php?cPath=174_175

So does dragonfly innovations
http://www.rctoys.com/rc-products-ca...EAGLETREE.html