Skiddins

The rules for brushless stock motors for BRCA (based on EFRA and adopted by many international organisations);

10.3 The Stack/Stator: Slot-less stators are not allowed. The stator must be
continuous laminations having the same overall shape, being one after the other
without anything in between. The laminations must be of one homogeneous material
without cut-outs, holes or hollow sections other than for the three slots of copper coil
wires and the three grooves for the screws used to hold the entire assembly together.
Stator minimum length 19.3mm, maximum 21.0mm. The thickness of the stator
laminations is 0.35 +/- 0.05mm. The Inside diameter of the stator must accept a ‘plug
gauge’ of 14.50mm +0/-.005 diameter, clearing the stator, plus its windings and the
electrical collection ring at any end of the stator.
10.4 The Winding: Only three slot (phase) “Y” (star) wound stators are allowed. No
delta wound stators allowed. Only circular (round) pure copper wire permitted. The
three slotted stator must be wound with: -
21.5T Class:- 21.5 turns of 2 x 21 awg. (or 0.724mm) max. wire dia.
17.5T Class:- 17.5 turns of 2 x 20 awg. (or 0.813 mm) max. wire dia.
13.5T Class: - 13.5 turns of 2 x 21 awg. (or 0.724 mm) max. wire dia.
and 2 x 23 awg. (or 0.574 mm) max. wire dia.
10.5T Class: - 10.5 turns of 2 x 20 awg. (or 0.813 mm)
and 2 x 22 awg. (or 0.643 mm) max. wire dia.
Dimensions are before lacquer coating
10.5 The Rotor: Shaft diameter must be 3.175mm where the pinion gear locates.
Only one piece, two pole Neodymium bonded or sintered, or Ferrite (ceramic)
magnetic rotors are permitted. Magnet length will be 25.00 +/- 1.00mm, not including
any non-magnetic balancing aids. Magnet outside diameter will be 12.20/12.51mm
(min./max. with no further tolerance) for the entire length of the magnet. The shaft
outside diameter where the magnet is mounted will be 7.25mm +/- 0.15mm, with this
diameter extending beyond the magnet to facilitate measurement.
10.6 All motors must have the original manufacturer’s logo or name
moulded/engraved by the manufacturer into the end bell/plate. A unique marking or
feature that is difficult to remove must be incorporated into the assembled motor to
identify the motor is either a 21.5T, 17.5T, 13.5T or 10.5T Spec. class motor. Spec.
motors introduced from 2011 onwards must have; the 'wind' # etched/engraved onto
the outer surface of the motor on a part of the motor that cannot easily be separated
from the stator windings. They must also be identified as Spec. class motors.
NOTE: The above rules form the basis for Brushless Spec. motors. If it is found that
variations of these motors from different manufacturers give large differences in
performance, then electrical tests may be adopted.

ROARS Motor rules;
]8.4.2 Specifications and Dimensions:
8.4.2.1 Only industry standard “05” size motors may be used.
8.4.2.2 All motors must have the original manufacturer's logo or name molded or
etched into the end bell.
8.4.2.3 Can must have the original manufacturer’s logo, name or mark.
8.4.2.4 Overall maximum diameter: 36.02mm measured at whatever point yields the
maximum dimension.
8.4.2.5 Maximum length: 53mm measured from the mounting face of the motor to the
furthest most point of the end bell, not including solder tabs or lead wires.
8.4.2.6 Shaft diameter: 0.125”.
8.4.2.7 Motor mounting holes must be on 1.00” centers.
8.4.2.8 Maximum Armature stack length: 22.6mm
8.4.2.9 Maximum Armature stack diameter: 23.2mm.
8.4.2.10 Only three pole armatures are permitted.
8.4.2.11 Magnets: Only ceramic, Neodymium, or Ferrite magnets are permitted. Cobalt
and other rare earth magnets are specifically prohibited.

I wonder why there are so many differences?

Shawn68z

iTrader: (6)

You might want to read ROAR Rule Book 2010, section8.8.4.1 Page 50.


They are more similar then different.

SlowerOne

As the ROAR President and the BRCA/EFRA Electric Boards are in constant communication over BL and LiPo/LiFe specs, methinks you have the wrong part of the Rule Book.

The clue could be in the phrase "only three-pole armatures are permitted", which applies to brushed motors, not brushless. At the risk of an outbreak of red-faced embarrassment Skiddins, are you comparing brushed rules with brushless? Oh, that'd be it...

Skiddins

Quite right, I screwed up, DOH!

The correct section;

8.8.4 “05” Size Dimensions:
8.8.4.1 Can:
Overall maximum diameter is 36.02mm measured at whatever point yields the
maximum dimension, excluding solder tabs, screw heads or lead wires. Maximum
length is 53.00mm measured from the mounting face of the motor to the furthest most
point of the end bell, not including solder tabs, lead wires or original manufacturer’s
logo or name. Motor mounting holes must be on 1.00- inch (25.40mm) centers.
8.8.4.2 Stack/Stator:
For Stock, Super Stock and Spec Brushless Motors: The stator construction must be
continuous laminations having the same overall shape, one after the other without
anything in between. The laminations must be of one homogeneous material without
cut-outs, holes or hollow sections other than the three slots for the round copper coil
wires and three slots for the screws used to hold the entire can together. The overall
stator length parallel to the motor shaft shall be a maximum 21.0 mm. The thickness
of the laminations shall be 0.35+/- 0.05mm. A ‘go-no-go’ gauge 14.500 +0.000/-0.005
mm diameter shall pass into the stator, clearing the stator plus its windings and the
electrical collection ring at the end of the stator.
8.8.4.3 Winding:
8.8.4.3.1 ROAR Stock motor: Only three slot “Y” wound stators are permitted. No delta wound
or slot less stators are allowed. Only circular (round) pure copper magnet wire
permitted. The three slotted stator must be wound with 17.5 turns of 2 strands of a
maximum diameter of 20AWG or 0.813 mm per slot. The resistance for each slot of
the stator shall be tested and a minimum resistance figure will be determined upon
submittal.
8.8.4.3.2 ROAR Super Stock motor: Only three slot “Y” wound stators are permitted. No delta
wound or slot less stators are allowed. Only circular (round) pure copper magnet wire
permitted. The three slotted stator must be wound with 13.5 turns of 2 strands of a
maximum diameter of 21AWG or 0.724mm and two strands of a maximum diameter
of 23AWG or 0.574mm per slot. The resistance for each slot of the stator shall be
tested and a minimum resistance figure will be determined upon submittal.
52
8.8.4.3.3 ROAR Spec 10.5 motor: Only three slot “Y” wound stators are permitted. No delta
wound or slot less stators are allowed. Only circular (round) pure copper magnet wire
permitted. The three slotted stator must be wound with 10.5 turns of 2 strands of a
maximum diameter of 20AWG or 0.813mm and two strands of a maximum diameter
of 22AWG or 0.643mm per slot. The resistance for each slot of the stator shall be
tested and a minimum resistance figure will be determined upon submittal.
8.8.4.3.4 ROAR Spec 21.5 motor: Only three slot “Y” wound stators are permitted. No delta
wound or slot less stators are allowed. Only circular (round) pure copper magnet wire
permitted. The three slotted stator must be wound with 21.5 turns of two strands of a
maximum diameter of 21AWG or 0.0724mm per slot. The resistance for each slot of
the stator shall be tested and a minimum resistance figure will be determined upon
submittal.
8.8.4.4 Rotor:
8.8.4.4.1 Modified Motor: External shaft diameter must be 0.125 inches (3.175mm).
8.8.4.4.2 ROAR Spec Motors: External shaft diameter must be 0.125 inches (3.175mm). Only
one piece, two pole Neodymium sintered, or Ferrite (Ceramic) magnetic rotors are
permitted. The magnet length shall be 25.0 +/- 1.00mm not including any nonmagnetic
balancing material. The magnet outside diameter shall be a maximum of
12.51 mm, no tolerance, for the entire length of the magnet. The shaft outside
diameter, where the magnet is mounted, shall be 7.25 +/- 0.150mm for the entire
length of the magnet. This dimension must be measurable without destroying the
rotor.