Motor and Propeller Test Set?

Hi, I'm looking for a device that can collect data from a Motor and a Propeller, running at a duty cycle corresponding to the range of a motor's voltage, to measure and analyze the following parameters:-Propeller RPM-Current Draw-Lift GeneratedAnd from there, can calculate:-Thrust Generated-Power Input-Power Output-Motor efficiencyAnd probably other ratings too. I've looked and can't find anything that could be used for the physical part of this concept, so I've attached a couple ideas.The hard part to me in this is the actual physical construction. Removing friction and inertia to negligible quantities and being able to measure lift accurately will be a challenge. Any input is appreciated.

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You are making it too hard.

Hang 4 equal length rods a few cm long, allowed to move in 1 dimension only ("forward").

From the rods, hang the "sled."

Motor mounts to the sled.

Sled should be able to swing smoothly and make several oscillations before stopping.

There are any number of force sensors, scales, etc. that can determine your thrust. A string can pull a line to an old fashioned fish scale. Do adjust the scale so that the thrusting motor is hanging vertically else a component of its thrust is moving it forward and thus upward.

Friction & inertia are not really worries if the system is generally free to move. Vibration of the motor/prop is sufficient to allow a generally free-to-move sled to move against any small static friction force. Inertia is resistance to change in velocity. Your sled should not be accelerating. It should be held in the neutral position by the force sensor.

Motor efficiency will be harder. You will really only be able to determine motor+prop efficiency without torque information.

Power input to the ESC won't be hard. Electrical power out of a brushless ESC will be more difficult.

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Ken December 31, 2010 at 8:42am

Well, there you go. For that price it isn't worth getting the tool box out.
Admin

Thomas J Coyle III December 31, 2010 at 7:35am

@David,

I have one of these: http://www.bphobbies.com/view.asp?id=A0320107&pid=V267609

You can buy it with the scale if you do not have one. Provides great empirical data that can be used in motor calculation spreadsheets.

Regards,

TCIII

BPH - BP Hobbies Thrust Test Stand Kit

Central New Jersey supplier of radio control models, parts, and accessories. Retail and wholesale to US and Canada.
Ken December 31, 2010 at 7:15am

You are making it too hard.

Hang 4 equal length rods a few cm long, allowed to move in 1 dimension only ("forward").

From the rods, hang the "sled."

Motor mounts to the sled.

Sled should be able to swing smoothly and make several oscillations before stopping.

There are any number of force sensors, scales, etc. that can determine your thrust. A string can pull a line to an old fashioned fish scale. Do adjust the scale so that the thrusting motor is hanging vertically else a component of its thrust is moving it forward and thus upward.

Friction & inertia are not really worries if the system is generally free to move. Vibration of the motor/prop is sufficient to allow a generally free-to-move sled to move against any small static friction force. Inertia is resistance to change in velocity. Your sled should not be accelerating. It should be held in the neutral position by the force sensor.

Motor efficiency will be harder. You will really only be able to determine motor+prop efficiency without torque information.

Power input to the ESC won't be hard. Electrical power out of a brushless ESC will be more difficult.

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Motor and Propeller Test Set?

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