DESIGN: Electrotor-SloMo ~ Special Tool - Test Stand - Dynamometer I

• Testing and Development of motor for Electrotor - SloMo.

• See Access program 'Motor.mdb'
• The RRPM - Drag (induced & profile) which will play a role. The equations for this are probably in the Helicopter.mdb.
• The torque-pitch will play a role.

• Bolt Retention: All 3 threads on the F&P axial have conventional CW for tightening the nut or the bolt. The current electric-rotor is attached to the shaft by a spline therefore I assume that it can safely rotate in either direction. The current propeller hub is attached to the shaft by taper lock. If the propeller is driven in a CW direction, when standing in front of it, any slippage of the hub on the shaft may want to loosen the bolt, particularly if the bolt is wire-tied to the hub. Check the direction of rotation.
• Torque Arm: If we wish to move the torque arm from the stator on the motor to the brake pad supporting frame this are will want to rotate in the opposite direction. Assuming that weights are still to be used, this means that the arm must be relocated to the operator's side of the stand. This maybe good since it places a greater distance between the operator and the arm.
• Consider using the very heavy plate as a counterweight. Have one end rest on the ground and the other end hung from the arm. To vary the resisting torque place notches or holes in the arm at select intervals. The plate weighs approximately 120 lbs, which is 60 lbs for one end. The maximum operational torque to be measured by all motors will be under 100 lbs-ft, therefore the greatest arm length for the notches/holes will be (100/60) * 12 = 20". The shortest are length, because of the drum brake will be at 6" which will be 100 lbs-ft * (6/20) = 30 lbs-ft. The current maximum torque achieved is 18.4 lbs-ft. Note that the 100 lbs-ft is at operational RPM. At slower rotational speed the torque will be higher. Therefore the maximum arm radius should be longer than 20". Ie. the flat bar should be about 4 feet long.
• Eventually consider the use of the actual rotor so that it can be tested once the motor is developed and/or develop both together.
• This may require that the rotor be remote from the test equipment and personnel.
• Should aero-rotor be mounted to electro-rotor? Perhaps not initially.
• 
• Perhaps the stator should be mounted on a tube, which intern is mounted on the two bearings. This tube would extend away from the stator so that it is easier to mount the torque measurement arm. This tube will probably better represent the eventual hollow core.
• Mounted horizontal or vertical?

• Sensors:
• Voltmeter. Have 2 from Kelly.
• The resistors for setting 100% to 52.3V (the maximum from the power supply) are 2 * 64.9K (in parallel) and 1 * 4.7K in series = 37.15K.
• Purchased small 2-way On-On toggle switch. For 48V and 72 V but are not using them.
• The second Voltmeter may be used across phase windings, to determine what the 'mean' voltage is [PWM percentage]. See Pulse Width Modulation Meter: lower down on this page.
• Ammeter.
• The multimeter is only good to 20 amps. We may need to measure up to 300 amps. Can we get ammeter on bench working? Check it out with multimeter at <20 A load.
• Have ammeter from Kelly, but it is not reading correctly.
• Kelly Ammeter positive connects to 5V power supply of controller Orange (4) wire, negative to Dark Blue wire (8). Black from Kelly manual, supplemented with pink added by me.
• The following is my initial testing of the ammeter.
• The resistance in the ammeter at 4.28 kΩ.
• The total resistance of the 75 Ω resistor and the ammeter, in series, is 4.37 kΩ.
• The ammeter shows 100% when it is connected in series with a 75 Ω resistor at 5.13 V.
• The multimeter shows the current flowing through the loop as 0.04? I = V/R = 5.13 / 4.37 = 0.00117 A = 11.7 mA
• The voltage drop across the resistor is 0.089 V.
• The voltage drop across the ammeter is 5.05 V.
• Using http://www.allaboutcircuits.com/vol_1/chpt_8/4.html
• Get it working properly if it is intended to be used.
• July 22, 2010. When the multimeter was reading 18A the needle on the current gauge was reading 16%. This might imply that the current gauge is set for 100% at 100 amps and not 100% for the 50-amperage maximum of the controller.

• Current transformers. These may only be good for AC currents.
• Clamp-on Ammeters: They are uncommon for DC but can be found.
• Here is one but it only goes to 200A DC. http://www.powerstream.com/DC-clamp.htm . The DC ones are quite a bit more expensive.
• The Hall effect type is more sensitive and is able to measure both DC and AC

• In the iron vane type, the magnetic flux in the core directly affects a moving iron vane, allowing both AC and DC to be measured

• Coil temperature indicator. Have 2 from Kelly. Their part number is KTY83-122. Plus have the multimeter one.

• Re motor temperature. The Kelly controller has an input for motor over temperature detection and protection with recommended thermistor. Also, the temperature setting can be changed with the configuration program. Perhaps this is the way to get motor coil temperatures.
• The thermistor for the Kelly controller is KTY83-122, which can be bought from Kelly for $5.00. Main Electronics says that they can get it in a weeks time. These are the specifications on the KTY83-122.
• The 2 thermistors from Kelly came with 2 1K resistors. I assume that they are to be connected in series, or parrallel?.
• Temperature Sensor - Motor:
• Winding Thermistors
• For more information see; OTHER: Electrical - Control - Temperature Sensor
• Perhaps this information comes from the Hall sensor assembly.
• Hall-1 has a wire that has been taken to the unused terminal in the connector. It is connected to a diode in the Hall. Perhaps it puts out a pulse a once per electrical 360º and could be used in conjunction with a timer to count the RRPM. If it is not used for temperature pickup.

• Bearings: We have them, except that the stator's bearing(s) and the plastic stator must be strengthened.

• Brake:
• First; See page with notes on fireplace hearth.
• Bought new 3.500 lbs electric trailer drum brake and controller.
• It is Left Hand. I.e. the drum turns CCW when looking at the brake linings with the drum removed.
• The bolts on the sheet metal brake plate are +/- 7/16" diameter. Form a square pattern with 2-13/16" between bolt centers. Will accept a square width of 4-1/4". Have a hole of 3"
• Consider buying 4-hole flange bearing (25mm?) to support internals and take the torque from the torque arm with torque measuring ability.
• Have one 4 hole cast flange bearing with 25mm insert. The 4 holes have a diameter of 11.5mm (29/64"). Form a square pattern with 69.8mm (2.75") between bolt centers. Have an overall square width of 95.2mm (3.75"). Has a width through set collar and to flange base of 1-3/8" Has a body diameter of 2-5/8". Bearing is a FYH F205G with a 25mm insert. It was bought from Ringball. The Fafnir number would be GE25KRRB. Housing number is T-40230.
• Note that is a self-aligning bearing and will therefore not hold the pads in alignment with the drum disk.
• Need 4-only 7/16" nuts (looks like NF) and lock washers.
• Need bar with hole pattern to suit above bolts in brake plate
• Bolts are 3/4" long. Housing is 1/2" thick. Nut and lock washer will be at least 1/4" thick. Arm must be 3/16" to 1/4" thick.
• We will need to drill 2 or 4 new holes in the plate to attach the bar. OR can the existing stud bolts be removed and replaced with longer bolts?
• Need adapter to connect drum to 25mm splined shaft and steel bolt and fastening to attach with.
• The bench must be modified to accept the drum brake.
• Torque indicator ~ Attach to the brake pad plate.
• The recent extension of the torque arm adds weight and the combined total should now be considered as 2.17 ft-lb for future calculations.
• http://www.flexibleassembly.com/Products/torque-tester/ATC-Series;jsessionid=1vv6M8kpv717cNKPddnhTMHzjT6zQ4SsGqQJN0kKnZ9B9LQBljbygpJRHvhxpMZJT4cyRW91Mt8Dd97pX8JL1wfy9Rsn3RrHsWmzmLBvS62gSzV2FgqfwghJHpQy51GL!1486307381
• Load Cells:
• http://www.transducertechniques.com/index-google-ad.cfm
• http://www.transducertechniques.com/HFG-Force-Gauge.cfm
• http://www.strainsert.com/pages/load-cells.php?gclid=CLyLoZj966MCFRk6agodTU5MCg

• See Inputs and Outputs in Access program 'Motor.mdb'.

• OTHER: CNC Work Station - Controller - Power Supply Unit (PSU) ~ KEPCO 21311, 48VDC, 12 Amp:
• Batteries Rick's 6 x 12 V =72 Volt.

• Honeywell; http://hpsweb.honeywell.com/Cultures/en-US/Products/Instrumentation/tempsensors/default.htm
• For the phasing graph see; DESIGN: Electrotor-SloMo - Control (flight & electric) - Control Circuit - Three-phase - Overview

• Using 2nd voltmeter to display PWM percentage.
• I think that the resistance should be half the 37.15K for 52V across the power source because this PWM is only reading the voltage drop across 1 of the 2 active coils. I.E. this resistance should be 18.575K.
• A small capacitor is across the meter to reduce pulsation.

• Control box to 2A Fuse: The wire (pink) is 22AWG and it can therefore handle 7 amps for chassis wiring.

 Calculations:

• The power output can be calculated as: Rotary power (Nm/s) = Pi × 2 × lever length (m) × revolutions per second × measured force (N)

• This Site:
• Access program 'Motor.mdb'
• Outside Site:
• Motor Calculations

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