The Slot Car World $5.00 Motor

11 November, 2002

A few weeks ago Slot Car World informed me that they had some nice little motors coming in for only $5.00 a piece. Well being that I am like most of you on a budget, I said "Great, send me a couple of them."

I am glad I did!

First of all, I want to make it clear that I am just like 99% of you, and that I am just a regular home racer. I do not have any technical testing equipment, so this small article will not have exact voltages, amperage draws or actual RPM results. If you are one of those people that need all the small details, such as what I have listed above, then this may disappoint.

For myself, I don't mind testing by hand to find out the results. As I was searching for a candidate to test on, and unfortunate (or for this test, fortunate) event occurred. My wife was doing laps in her new GT40 when right at the top of "Big Piney" the motor gave out on her. As she coasted slowly to the start/finish line, I thought:  "Well lets just see if these motors will fit..."

Luckily, they do. Of course, first step is to get your soldering iron out and remove the wires connected to the old motor. Then simply pop it out by hand. After removing the old motor, I used a small flat tip screwdriver and popped the pinion off the shaft. Ninco makes a great gear puller for times like these, but in many cases I just use a screwdriver. I have never damaged any gears or motor casings doing it this way, and if you don't have this puller handy, give the old reliable flat tip screwdriver a chance.

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The Scalextric Sport motor pictured has splines on the shaft to hold the pinion in place tightly, and works very well. However, the new motor has a smooth shaft and I was concerned the pinion would not hold tightly, and therefore spin freely on the shaft. So after looking at it, I test fit the pinion on the shaft and found it to be quite a snug fit. I still wanted to see about getting this pinion mounted with more reliable strength, so I decided to use Super Glue. After looking at the shaft, I wondered how well the Super Glue would hold on the smooth surface of the shaft. So I tried using some Emory cloth sand paper and lightly scored the shaft, this didn't take put a few passes until it was roughed up enough for my taste, to allow the glue to have a better surface to adhere to and make a stronger bond.

BEFORE you add the glue, slide the pinion in place, and test fit it into the car. It is a painless snap in process and the motor fit perfectly in the car. Now I took the rear axle assembly and rotated it by hand to make sure the pinion was lined up right. I also rotated it and moved the axle assembly from side to side, to check the pinion flange clearance. Next it was time to re-connect the wires, I hooked them exactly as they were attached on the original motor. I tinned the motor tabs first with a slight amount of solder, and then re-attached the wires.

There is a flat flange edge along the pinion, and you don't want this edge (flange) making unnecessary contact with the larger Spur gear. Then I put the car on the track, and while having the rear end raised, I applied some power to hear if I had installed the gear properly. After this, I slowly applied power and cruised the car around the track, listening for any abnormal sounds coming from the gears.

There wasn't any, and she ran just as quiet and smooth as the original. Now it was time to apply the Super Glue. I used a VERY small drop on the front of the gear applied with the tip of a toothpick. This was just enough, and it created a tight, durable bond.

Again, I cannot confirm or deny the rating of 24,000 RPMs, but I can inform you that this motor is QUICK. This GT40 ran as smooth and fast as it had before, with even more power! In extended testing and racing, so far this motor has performed well.

For $5.00, it isn't a bad investment to have a couple handy "just in case".

 Harry

As always, feel free to email me at wiseone@yhti.net about this technical tip, or just the hobby in general.