NAMBA March 2021 Web

Proposal – Modification to Section 28 – Electric, Rule E.6 – 1/8 SCALE UNLIMITED HYDROPLANE. Reasoning: The 2018 rule change incorporated several technical values that were not physically measurable without destructive testing, using equipment that is not in normal circulation. With the rule change these specifications are removed. Much like P-ltd, the motor list has already had at least one of three listed options go out of production. The motor list is replaced with a dimensional limit and testable kV limit. The change establishes an inspection process to regulate motor performance that is not cumbersome or intrusive. The end result is an enforceable rule set that will not need to be readdressed in the near future, and again allow 1/8 scale FE to be run as an official national class eligible for records. Motor Tech form to follow if rule passes. To be supplied by FE chair Current (areas in bold will be deleted if rule passes): E. SPECIALITY CLASSES 4. 5. 6. ELECTRIC 1/8 SCALE UNLIMITED HYDROPLANE a. General Rules i) Electric Scale Unlimited Hydroplane rules will follow the Scale Unlimited Hydroplane rules (see Section 21) with the exception of the following: ii) Electric Scale Unlimited Hydroplane rules are intended as a supplement to the Electric general rules. In the case of a conflict with the Scale Unlimited Hydroplane rules (see Section 21), the Electric rules will prevail. b. Power Specifications i) Approved Motors (a) NEU 1527 1.5Y 850KV (b) HET Typhoon 700-98 840KV (c) Turnigy SK3-3994 850KV ii) Twin motors are not allowed. c. Drivetrain Specifications i) Either a cable or hard shafts may be used, no gear boxes allowed. ii) Any propeller may be used up to maximum of 57mm in diameter. d. Electronic Speed Controls (ESC) i) Any ESC may be used as long as it is rated to a minimum 130 Amps and rated to handle a minimum of 8S battery configuration. ii) Anti-spark resistors are advised on all speed controllers. e. Batteries i) A maximum capacity of 8S Lithium Polymer (LiPo) batteries are allowed. The maximum mAh capacity of the battery pack(s) will not exceed 6000 mAh. Only LiPo batteries with a cell rating of 4.20 or less volts per cell are allowed. ii) LiHV batteries with per cell capacities to 4.35 volts or higher are not allowed. iii) Manufacturer’s minimum discharge of 30C constant but no higher than 65C constant is allowed. Proposed (areas in bold are new additions if rule passes): E. SPECIALITY CLASSES 6. ELECTRIC 1/8 SCALE UNLIMITED HYDROPLANE a. General Rules i) Electric Scale Unlimited Hydroplane rules will follow the Scale Unlimited Hydroplane rules (see Section 21) with the exception of the following: ii) Electric Scale Unlimited Hydroplane rules are intended as a supplement to the Electric general rules. In the case of a conflict with the Scale Unlimited Hydroplane rules (see Section 21), the Electric rules will prevail. b. Power Specifications i) Motors shall not exceed the manufacturer’s kV rating of 860 kV (950kV breakout threshold). ii) Motors may not have a motor case exceeding the following dimensions, including any bearing protrusions: (a) Length: 105 mm (4.134 in.) (b) Diameter: 42 mm (1.654 in.) iii) Motors without permanently marked factory kV rating will undergo technical inspection to verify rule compliance. iv) Twin motors are not allowed. c. Drivetrain Specifications i) No gear boxes allowed. ii) Any propeller may be used up to maximum of 57mm in diameter. d. Batteries i) A maximum capacity of 8S Lithium Polymer (LiPo) batteries are allowed. Only LiPo batteries with a cell rating of 4.20 or less volts per cell are allowed. ii) LiHV batteries with per cell capacities to 4.35 volts or higher are not allowed. e. Motor kV inspection procedure and formulas i) The following formula will be used to determine a brushless motor kV output. k = (120f/p)/(1.343 ) Variable definitions: = frequency of the motor, as measured in hertz (Hz) = number of poles in the motor = voltage measured across the motor, as measured in volts (V) ii) It is recognized that identical technical inspections of FE motors can provide different results for two or more identically represented motors. Because of this, 950 kV is the “may not exceed” kV output value. iii) Technical Testing Process for Determining a Brushless Motor KV Output: (a) Tools/motor information/KV formula needed for testing: (i) Drill motor capable of at least 1200 RPM. (ii) Multimeter with frequency-checking capability. (iii) Number of poles on the motor to be tested (I.E., 2, 4, 6). (iv) Formula as stated in rule E.6.e.i in this section. (b) Testing motor KV output: (i) Attach the multimeter leads to any 2 of the 3 wires extending from the motor. (ii) Connect the motor shaft to the drill motor chuck. This can be done by removing the motor from the boat and directly attaching the drill chuck to the motor shaft. If the motor is still in the boat, remove the propeller and attach the drill chuck to the stub shaft/cable driveline. (iii) Set the multimeter to “Frequency” mode and spin the motor with the drill until the reading is shown. Record the frequency. (iv) Set the multimeter to “Voltage” mode and spin the motor with the drill until the reading is shown. Record the voltage. (v) Plug the f, p and V values into the equation provided (28.E.6.e.i). The result is the motor’s KV output.