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Electric Stunt => Gettin all AMP'ed up! => Topic started by: jim gilmore on March 26, 2015, 09:30:10 PM

Title: electric motor test stands ??
Post by: jim gilmore on March 26, 2015, 09:30:10 PM
Does anybody bench mount their setups prior to installing them in a model and how do you set it up ?
Title: Re: electric motor test stands ??
Post by: John Cralley on March 27, 2015, 10:45:33 AM
I have run some setups (component combinations) in the past simply using a plywood motor mount attached to the end of a 1" x 4" in turn attached to a work bench. I wanted to check static amps pulled with various prop/motor/rpm combos. I used a watt meter to monitor the amps. Small light objects, papers and so on should be clear of the slipstream!  >:(  :(  At least you don't have to worry about exhaust fumes (unless you flame some components LOL).

Bare in mind that static amps will be higher than what the combination will pull in flight. ALSO you should NOT run a setup that is drawing near max capacity for any length of time!!! You may be sorry if you do!!!  y1

Such measurements are of limited usefulness - the proof of the pudding being what you get during an actual flight situation.

I also have jury rigged a digital scale to measure the thrust generated in a static situation from a combo mounted in a model. Again this only gets you into a fairly large ballpark. The proof is in the flight situation. Some Castle Creations ESCs can record parameters during flight and this can be very useful.

Title: Re: electric motor test stands ??
Post by: Motorman on March 27, 2015, 09:09:21 PM
Don't do it you'll fry your ESC.


MM
Title: Re: electric motor test stands ??
Post by: CircuitFlyer on March 28, 2015, 08:06:55 AM
If you monitor the temperatures of all the components it doesn't hurt a thing.  Mount the ESC in the prop slipstream to be safe.  I bench test all my power systems.  As John says, it gets you on the ball park and you know the systems limitations.  I have a set-up with a digital scale to measure static thrust.  I like to have a record of volts, amps, RPM, temperature and thrust for a selection of props.  The final selection and settings are determined after some test flights at the flying field.  If you don't at least know the static current (usually the peak current of any flight) you run the risk of overheating components. 

Paul
Title: Re: electric motor test stands ??
Post by: Fredvon4 on March 28, 2015, 02:08:41 PM
I have a friend who is learning the in and out of electric...I am still a slime guy

He has one of these in his shop and it works well

http://www.hobbyking.com/hobbyking/store/__66623__Turnigy_Thrust_Stand.html

He learned enough to stop testing motor and esc combos and now has a largish motor and adjustibility of RPM set up on it

He sets a base prop and records thrust at specific static RPM then as he trims or reshapes his similar brand and size props he knows something useful

He also uses it to test all new props at a low RPM and can tell immediately if one is out of balance

Just another tool and he claims it cuts down the in flight testing that he is fanatical about

Hell he even set up a strobe so he can track a blade and see if it is flying on the same plane as the other
Title: Re: electric motor test stands ??
Post by: Joe Yau on March 28, 2015, 04:18:55 PM
Don't do it you'll fry your ESC.


MM

I've heard that you could actually run the motor with no prop for testing.. that way it minimize the load to prevent frying the esc.
Title: Re: electric motor test stands ??
Post by: David Hoover on March 28, 2015, 07:34:07 PM
I've heard that you could actually run the motor with no prop for testing.. that way it minimize the load to prevent frying the esc.

But that won't tell you much about propellers.

Title: Re: electric motor test stands ??
Post by: Howard Rush on March 29, 2015, 12:20:19 AM
Operating a propeller at zero airspeed won't tell you anything about it either.
Title: Re: electric motor test stands ??
Post by: Mike Anderson on March 29, 2015, 09:28:37 AM
But that won't tell you much about propellers.



It won't tell you much about motors, batteries or ESC's either.
Title: Re: electric motor test stands ??
Post by: CircuitFlyer on April 03, 2015, 08:10:15 AM
The first thing I do with a new motor is run it without the prop.  You would be surprised how out of balance they can be straight from the factory.  I usually need to add a tiny bit of weight (electrical tape) to the outside diameter of the can to get it to run smooth and quiet.  Always check the balance any new props before use as well.

True, operating a prop at zero airspeed tells you squat about the prop.  But, testing 6 various props on the test bench will confirm that you have 6 very different props, then you can decide which 3 to leave at home and which 3 to take to the flying field.

Paul