PDA

View Full Version : Discussion Brushless RPM Sensor/Tach from Eagle Tree Systems, LLC


billpa
Dec 04, 2006, 12:21 AM
Brushless Motor RPM Sensor from Eagle Tree Systems, LLC

Eagle Tree Systems is pleased to announce our innovative new Brushless Electric Motor RPM Sensor/Tachometer. Our Brushless RPM sensor makes it extremely easy to measure RPM with any of our Eagle Tree data systems.

http://www.eagletreesystems.com/accessories/images/brushless-rpm-sm.jpg

To measure RPM on your brushless electric Plane, Heli, Car or Boat, just tap one wire from our tiny new sensor into one motor lead, enter motor parameters in our software, and you are ready to go!

The Brushless RPM Sensor is compatible with our MicroPower, PowerPanel, Seagull and Data Recorder products, and will be shipping to our dealers and customers on approximately December 14, 2006 (just in time for Christmas)! Preorder yours today!

http://www.eagletreesystems.com/images/brushless-screen-sm.jpg

See your Dealer, visit our site at http://www.eagletreesystems.com or email sales@eagletreesystems.com for more information.

http://www.eagletreesystems.com/images/brushless-graph-sm.jpg

Note: Using the Brushless RPM Sensor with our Seagull and Data Recorder products requires firmware level 4.XX or higher, which has been shipping since approximately August, 2005. Click here (http://www.eagletreesystems.com/Support/Manuals/Upgrade-Info.pdf) for Upgrade Info (PDF).

pmackenzie
Dec 04, 2006, 12:23 AM
Cool product.
I notice there are two leads , motor 1 and motor 2.
Can you measure two motors with this, or do you need to hook up to two phases?
Pat Mackenzie

Larry3215
Dec 04, 2006, 01:31 AM
Cool idea!

Good question Pat!

Larry

green66
Dec 04, 2006, 03:15 AM
....just tap one wire from our tiny new sensor into one motor lead.... Can the sensor wire just be soldered or clipped to a spot of bare motor lead anywhere along the lead?

Could the sensor have any load/timing/phasing effect on the ESC, or otherwise affect system performance?


....enter motor parameters in our software.... What are those parameters?

Will the accuracy of measured rpm's be affected by the accuracy of the input values?

billpa
Dec 04, 2006, 09:27 PM
Hi All,

Thanks for the feedback.

Pat, for the large majority of motors, Motor 1 lead only need be attached. For some motor designs, both leads will be needed.

Green66, yes you can just solder or clip the sensor lead to the motor lead, anywhere along the lead. No, the sensor should have no affect on the ESC whatsoever. Of course, we recommend a ground check before flying after installing any new electronics.

The motor parameters are simply the # of motor poles (available from your motor mfg), and the gear ratio (normally 1.0 for planes). If one or both of these parameters is unknown, the simplest way to determine them is to run a test with a handheld tach, noting the max RPM. Then download logger data, calculate the % error, then adjust the input factor read the correct value.

Regards,

Bill, for Eagle Tree Systems, LLC

everydayflyer
Dec 04, 2006, 09:42 PM
A few known Tach numbers or ones which work for me.

HiMax 2815 (14) Same as the number of magnets

Mega 16/7/6 (6)

Mamba Max 5700 (2) according to CC All of the Mamba motors (1/18th and 1/10th) are 2 pole slotless designs.

FYI I used servo leads (pigtails) on the ESC to Motor lead(s) and matching pigtail on the ET Tach expansion board so that it is very simple to move from on application to another.

Charles

mjdoz
Dec 04, 2006, 10:32 PM
Bill,

went to place an order and noticed shipping to Australia was more than the cost of the sensor. Any idea when the local Australian suppliers will have stock?

Thanks

Michael

Bthree
Dec 04, 2006, 10:53 PM
Who sells Eagletree in Aus ?

ExtremeRC but who else ?

mjdoz
Dec 05, 2006, 12:46 AM
Wattsup as well.

also fast electrics http://www.fastelectrics.com/eagletree.asp

Not sure if anybody else. Try Google with "Australia only" selected

Michael

xorbe
Dec 06, 2006, 10:50 PM
How can I get this new RPM sensor sooner than later?
edit: Well I did the pre-order via ETS website...

xorbe
Dec 14, 2006, 02:20 PM
The Brushless RPM Sensor is compatible with our MicroPower, PowerPanel, Seagull and Data Recorder products, and will be shipping to our dealers and customers on approximately December 14, 2006 (just in time for Christmas)!Ding ding! Today is the 14th!

billpa
Dec 18, 2006, 02:55 PM
Hi All,

We have been the unfortunate recipients of this:

http://www.komotv.com/news/4935976.html

We now have power back on, and are using cellphones for internet access.

The mail has started to run again, and we are supposed to receive the brushless expanders from the factory today, which means shipping starting tomorrow.

Sorry for the delay!

Regards,

Bill, for Eagle Tree Systems, LLC

xorbe
Dec 28, 2006, 03:26 AM
I have RPMs on my charts now! :D :D :D
Just one lead needed for JGF 500T 12-pole outrunner.

update: seems like my CC60 never goes all the way to 0 RPMs... stuck at ~4K minimum -- is this due to the active brake function? No big deal, because I'm interested in max RPMs at speed really.

billpa
Dec 28, 2006, 04:50 PM
Hi Xorbe,

Great news!! Yes, I suspect the active brake is sending pulses to the motor to keep it still. Is it possible to briefly turn off the brake, to see if the pulses stop? We can do some things in firmware to detect/eliminate that if need be.

Regards,

Bill, for Eagle Tree