Freescale Cup DC Motor Specifications

[#1]

Further Reading

MCU 101: How does a DC Motor work?

MCU 101: Pulse Width Modulation for DC Motors

Specifications of Included DC Motor

Conditions of Standard Operation
Driving Voltage:	7.2V
Direction of Rotation:	CW viewing from metal housing
Position of Motor:	Horizontal
Operating Temperature:	10 to 30 (Celsius)
Operating Humidity:	30%RH to 95%RH
Electrical Characteristics
No Load Speed:	16000+/- 3200 rpm
No Load Current	220mA (max)
Mechanical Noise (Distance from housing side A=10cm Background Noise =30dB (max)	75 dB
Stall Current: (two points method 1.2&3.9mNm)	3800mA (max)
Stall Torque (two points method 1.2&3.9mNm)	80g.cm min
End Play of Shaft	0.05~0.60 mm

[miroslavdobrev]

Hello.

The information given here seems a bit outdated already. What motors are currently allowed for the classic format (not the innovation one)?

We have a standard kit but there is a problem with the motors. However on the motor packages it is not specified what is the actual motor model number, so we cannot order the same motors.

In the attached specifications document to this topic it says the model number is RN260. However in the innovation challenge topic there is a different information:

Freescale Innovation Challenge EMEA 2015

In the attached document (Freescale Cup Models.pdf) there is a list of different car used through the years. I guess the current model is car C. If that is true, the motor model number specified in the document is RS-280.

Those two motors (RN260 and RS-280) have quite different characteristics. Can you please specify which one is currently allowed. Accurate specifications data and website to order will be very useful as well.

Thank you.

[FlavioStiffan]

there re have been 2 generations of standard motors delivered with the standard kit. Both are allowed. If any replacement used, the same both motors are allowed for replacement

[dc37]

Hi, after some extensive sleuthing over the 'net with the various incomplete specs that have been given about the 2 generations of motors, I've concluded that the motors are not, in fact, the RS280 motors that are noted, but actually motors with the 260 size and 2670 winding.

Let me explain:

1st generation motors were the 260 size with the 18130 winding. These are quite well approximated with the Jameco 18130 motors. The specsheet on the RN260-18130 motors also specifies them for 4.5V but it's usually fine as long as the power dissipation doesn't go too high.

http://www.jameco.com/1/1/1119-qjt-260-18130-motor-dc-1-5-4-5vdc-0-4a-nominal-voltage-3vdc.html

Some testing that I did seems to corroborate the fact that it is quite similar if not identical to the noted motors:

http://www.standardmotor.net/sc_webcat/ecat/product_view.php?lang=1&cat=205&id=52&page=1

2nd generation motors are very poorly documented. I burned one out quite quickly when testing the stall characteristics, thinking it was equivalent to the spec sheet denoted here - instead, it drew about 2x the current specified in the datasheet and started smoking as soon as I stalled it, drawing about 8A right prior to becoming nonfunctional.

As noted above in https://community.freescale.com/servlet/JiveServlet/download/102757-5-283258/Freescale+Cup+Models.pd...

the motor characteristics are about right for what I observed. However, the RS-280 motor is physically too large to fit in the Freescale chassis.

Therefore, I took some time and used those characteristics in conjunction with the characteristics I observed, and deduced that it must be closest to this motor:

http://www.jameco.com/1/1/1011-rc-260ra-2670-power-misc-4-5-volt-dc-motor-15298-rpm.html

And in fact, after testing, the characteristics do seem just about right.

If any staff member can confirm these results, that would be great.

I am now searching for the proper gears to go onto these motors, since they are quite fragile at maximum PWM, and pulling off the gears from dead motors is rather annoying. If anyone can help provide some more specs on the gears, that would be great; right now I have insofar deduced that they are 9 tooth 0.6? module gears, with 2mm shaft diameter, though I haven't been able to find anything that works yet.