Basic size

[psycho]

Hi everyone!!!
Will like to know the physical size of the basic 4200. Are they smaller than a brushed 540? Did you know if they are legal for 2wd buggy racing?
Thanks:037:

[coolhandcountry]

The basic 4200 has the same diameter as a 540. It is shorter than a 540 s can.

[joostin420]

they do look small, but they pack quite a punch. the 5300 is very fun on 7-8cells:



justin

[maxxdude1234]

Look on here psycho: www.bk-electronics.com . The BASIC is 36mm in diameter and 37mm long.

[Batfish]

Originally Posted by psycho

Hi everyone!!!
Will like to know the physical size of the basic 4200. Are they smaller than a brushed 540? Did you know if they are legal for 2wd buggy racing?
Thanks:037:

If you are asking about ROAR legality, that's up-in-the-air as far as I know. Take the specs of your controller and motor and compare to the ROAR rules. There's nothing in the rules that say you CAN'T use a sensorless motor and controller, but there must be a rules reason that noone is using them.
If you're wondering if it's legal to race at a local track, only the track owner(s) can make that decision.

Either way, you're sure to be pleased with the motor however you choose to run it :)

[SpEEdyBL]

The basic motors are not roar legal. Five reasons. 1. Can length, 2. rotor size, 3. winding style, 4. $$ cost 5. I think they need to have solder tabs.

[squeeforever]

is that why all the novaks and stuff have tabs?

[Batfish]

Here's a copy and paste from ROAR's actual brushless motor rules:

Modified Electric Classes include brushless motors using the following rules:
Modified Brushless ROAR Rules
8.7.5.0 GENERAL DEFINITION OF A BRUSHLESS MOTOR
8.7.5.1 Sensored or sensorless motors are allowed.
8.7.5.2 The motor has to be rebuildable. Ball bearings are allowed.
8.7.5.3 If the motor is sensored:
It must use a six position JST ZH connector model number ZHR-6 or equivalent
connector with 6 JST part number SZH-002T-PO.5 26-28 awg contacts or equivalent.
Wire sequence must be as follows:
Pin #1- Black wire-ground potential
Pin #2- Orange wire-phase C
Pin #3- White wire-phase B
Pin #4- Green wire-phase A
Pin #5- Blue wire-temp control, 10 k Thermistor referenced to ground potential
Pin #6- Red wire-+ 5.0 volts =/- 10%
For clarification pin #1 is on the left hand side of the above connector with the wires
exiting the top of the connector and the plastic tangs that hold the contacts in the
housing are facing forward. See drawing below.
Compatible speed control must use the six position JST header part number X-6B-ZRSMX-
TK (where the X denotes the style of the header), or equivalent.
The power connector has to be clearly marked A, B, C. on both speed control and motor.
A for phase A
B for phase B
C for phase C
42
8.7.5.4 “ 05” size dimensions.
Can:
Overall maximum diameter is 36.02mm measured at whatever point yields the
maximum dimension, excluding solder tabs or lead wires. Overall minimum diameter is
34.00mm measured at whatever point yields the minimum dimension, excluding solder
tabs 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. Minimum length is 50.00mm 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.
Stack/Stator:
Stack minimum length 19.30mm, maximum 21.00mm. Stack inside diameter minimum
12.50mm, maximum 16.00mm. If a stack is used then it must be continuous. The
laminations have to be one after the other without anything in between. The thickness of
the stack plates is 0.35 +/- 0.05mm. All laminations must be of the same material.
Winding:
Only three slot (phase) “Y” wound stators are permitted. No delta wound stators allowed.
Only circular (round) pure copper wire permitted. No turn limit.
Rotor:
Shaft diameter must be 0.125 inches (3.175mm). Only one piece, two pole bonded
Neodymium or Ferrite magnetic rotors are permitted. Magnet minimum length 23.00mm,
maximum 27.00mm. Magnet minimum diameter 12.00mm, maximum 15.50mm.
8.7.5.5 All motors must have the original manufacturer’s logo or name moulded into the end bell.
8.7.5.6 A minimum of two thousand (2000) brushless motors must be available at the time of
approval. A minimum of three hundred (300) brushless motors must have been sold to at
least three (3) distributors or hobby shops or OEM’s at the time of submittal. The
manufacturer has to provide an address of a hobby shop or the like, that any driver who
wishes to obtain these motors at the time of the approval can do so. No hybrid (mixing of
parts from approved brushless motors) allowed.
8.7.5.7 The maximum retail price of a modified brushless motor shall be $129.00

8.7.5.4 Would seem to indicate that either solder tabs or lead wires are acceptable, since it mentions both in the measurements.
8.7.5.5 Appears to be a problem for the motors we use because I haven't seen Lehner or Feigao or BK moulded into the motors.
8.7.5.7 Is an issue with the Lehner since the Lehner is $150 and the limit is $129.

Others can also scrutinize this information, dis-assemble their motors, and break out the calipers to see if the motors we use break any other rules :003:

[coolhandcountry]

It seems the motor is to short as well. If it is 37 mm long and it requires a minimum of 50mm. That is very interesting.

[pcnutz]

just to let you know even though I done the 1/8 scale buggy tripple with my 4200, thier is a unbanlance in the truck or buggy with a lighter motor you have to compensate on jumps

[Batfish]

It may be a little bit of a thread hijacking here, but I've often wondered if it's possible to put together a sensorless brushless setup that meets all ROAR rules requirements. Maybe a pre-configured system like the Mtroniks would work, but I don't think they are considered rebuildable since they have a pressed end bell.
Either way, it's something I've wondered since ROAR first added these rules last year and it would be nice to find a way to satisfy these requirements with a sensorless system.

[rchippie]

A lot of people dont know that NOVAK help wright the roar rules for brushless. I think thats why there sensored BL sestems are legal & other companys sensorless BL systems are not legal.

[Batfish]

Originally Posted by rchippie

A lot of people dont know that NOVAK help wright the roar rules for brushless. I think thats why there sensored BL sestems are legal & other companys sensorless BL systems are not legal.

Novak and LRP both had a hand in helping ROAR with the brushless rules, as far as I am aware. As far as I'm concerned, Novak earned the opportunity to help shape the brushless scene by pushing forward and releasing the first consumer-friendly, drop-in brushless system that just about anyone could use. Whether you've owned either the SS5800 or SS4300 systems or not, you probably know someone who did/does. It's that type of popularity that has brought the brushless technology into common R/C lingo now.
People actually know what you are talking about when you say "brushless" now, whereas as recent as just a year ago people would still say "huh?". :003:

[RC-Monster Mike]

You will see "legal" sensorless systems soon. Bk is working with Orion developing a system, which is being tested as we speak(has been in testing for quite a while).