[samste]

Guys Just a Heads Up,

Re - Rare Bear Setups.

From some Testing and Trying different Esc's and Lipos i have Noticed that in actual Fact the motor setup is sweet for 3s But 4s its Running way over the specs.

How Do I know this, i have found that when you are full throttle on 4s setup. the Standard Esc is blocking all the extra current to the motor and is running in burst zone of the Esc.

I found this out on my on my eflite as i thought it was maxing at 38 amps on my 30 eflite esc but that was its burst max zone. Hence the reason for it burning out when you are full throttle, it just too long and too much, as it cannot get rid of the heat and its stopping any excess current to motor..

I have thrown in a 50 amp Esc and sure enough i drawing now 56 amps on full throttle.

I'm Using Nano Techs that can produce 45-90 amps so hence the amps just pour into the motor.


Here is some Tests Data all 1000ma lipos

Using 50 amp esc and stock motor and a Watt meter

5x5 prop 3s turnigy 20-30c 23 amps full throttle

5x5 prop 3s nano tech 45-90c 30 amps full throttle

5x5 prop 4s nano tech 45-90c 56 amps full throttle 769 watts

4.75 x 4.75 prop 4s nano tech 45-90c 51 amps

4.5 x 4.5 prop 4s nano tech 45-90c 41 amps

Rare Bear Stock prop 4s nano tech 45-90c 58 amps


i am Now Thinking that a 30 esc is prob what you would want to put in as it will limit the amps to max 40 which in turn will protect the motor from burning out.
But in Turn you will burn out the esc if pushed too far.

Can this stock motor cope with 56 amp bursts, will it stay cool enough ? I think Not !

Possibly need to re think the way to fly the rare bear in short bursts at high speed and plenty of esc cooling.

Possibly fit the a lower Amp Esc to outside of the body for full cooling so in burst limit zone it won't over heat and reduce max amps to motor.
Or Limit Throttle max on Tx to a safer amp level.

Alternately change flying habits with rare bear, do one fly and let esc cool before next flight on 4s

I'm Curious when they produce these high spec setups did they actually try a higher amp esc and see the actual current drawn by motor and prop configuration or they thought people will fly only in short full throttle bursts.

PLEASE LET ME KNOW IF MY TEST DATA IS WRONG AS I HAVE DONE THESE TESTS BASED ON A ASSUMED GOOD WORKING ORDER STOCK MOTOR

Steve.

EDIT 03/05/2012
I believe the Results above are a Clear Indication of a Faulty Motor windings and a Esc issue caused by faulty motor as new Tests Reveal with new Stock Motor and New 35 amp esc testing at Full Throttle yet with old esc same results -

New Test Results
28 amps 400watts on 4s 1000ma lipo 45-90c, 6x5 apc prop