Parts: Motors

Do you want a faster motor?


Tamiya offers a line of motors (made by Mabuchi) for their Mini-4wd race cars and they are made to run on 2xAA batteries just like our monorails.  But there are some big differences between race car motors and train or monorail motors.  A race car motor only has to last until the end of the race, often only minutes or less.  Efficiency (battery life) is not an issue.  Our motors should last for many hours and we expect the monorail to run for hours on a set of batteries.  So what is a good compromise for motors?


Tamiya has a chart showing the specifications of the motors, including: RPM, current draw, and torque.  Current draw is maybe for the motor in a race car, our results will vary considerably. For example, the "Torque Tuned" motor I tested only drew about half of what the chart indicated and turned about half the rpm listed so the numbers don't mean much except as a comparison between motors.  I decided to draw an arbitrary line at 2 A current and am looking at motors below that figure,  The motors of interest are: "Torque Tuned", "Atomic Tuned", Hyper-Mini" and "Rev Tuned".  "Touch Dash" has an auto shut off feature so I will not bother with that one.  I also had to test the "Plasma Dash" because it is the fastest and has replaceable brushes.  It also has a better commutator as I found out later.


There are plenty of Mabuchi FA-130 type motors available on the internet, the same (sort of) as in our monorails.  However, the Disney monorail motor has carbon brushes (or so they appear) that are good for longevity.  Most other almost identical motors have metal leaf brushes that cost less and do not last long.  One test showed a short life for these motors, with one stopping after about 10 hours.  Another motor ran for over 70 hours so I wonder if it had different brushes.  Running the motors on more than 3 V greatly shortened the life.


http://www.pololu.com/docs/0J11/1


Tamiya's "Torque Tuned" motor has metal brushes and the commutator was already showing wear after maybe 10 minutes of running (in a monorail) with 2xAA NiMH batteries.
Btw, most of these motors have identical endbells (the rear plastic housing) and the brush assembly can be swapped between them.  I replaced the "Torque Tuned" brush assembly with the one from the original motor and it fit perfectly.


http://www.mabuchi-motor.co.jp/en_US/technic/t_0300.html


Note the word "economical" in the description for the metal brush!  The designation "FA" indicates a metal brush so the original motor is actually a "FC" type.  The only FC-130 listed for 3 V is not our motor but Mabuchi will make custom motors for a big customer so it appears we have the FA-130 18100 armature and the FC-130 brushes.


http://www.mabuchi-motor.co.jp/en_US/technic/t_0302.html


FC-130 motors are difficult to find, almost all the motors of this size sold on the internet are FA versions.  They may work for our monorails but I suspect the life will be too short, especially for any motor faster than the original.  What to do?
Tamiya's "Plasma Dash" is a better motor with replaceable brushes but it is made for serious racing and takes far more current than the original motor, 3-4 times as much!.  It also makes the monorail run off the beam in a curve.  However, by mixing and matching motor parts we may be able to have it all!  My first choice would be the "Torque Tuned" or "Atomic" (or maybe "Rev Tuned") armature in the "Plasma Dash" housing; that gives more speed, greater longevity, and rebuild capability all in one package.  The only downside is cost since we have to buy two motors to make one.


My second choice would be the "Torque Tuned" motor with the brush assembly from the original motor, giving some of the advantages without the cost.


On to the shameless plug: if you are not interested in doing the work I can provide a motor with just about any combination of components you want!  Bear in mind that the Disneyland monorail with remote will not work reliably beyond a certain current draw, a fast motor may make the control cut out.  The non-remote monorails do not have this problem although the switch or the RFI supressor (little cylinder soldered to the motor lead) may burn out with a fast motor.  My choice of motors with the "Torque Tuned" armature only draw a little more current then the original motor and should last a long time.  They also do not provide a lot of speed but as noted in my article on "power" it is almost double the speed of the original.


Did you really think this was easy?  ;)