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Discussion Starter · #1 ·
I have just replaced the standard Slot.it 21,500 rpm motor in my car (which is fitted with a Slot.it HRS2 chassis) with a Slot.it 25,000 rpm one. On my home layout, using standard Scalextric hand controllers and power supply, i note absolutely no change in the car's lap times. The gearing and everything else was left intact. I would have thought that the higher power and torque figures of the 25k motor
(11.2 W, 180 g.cm vs. 9.6 W, 170.g.cm) would lead to an instant improvement.
Anyone else have a similar experience ? The 25 k motor sounds very healthy when revved with the wheels lifted, more so than the 21.5 k one. Is it possible that the 25 k motor needs a better (higher amperage) power supply ?
 

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Rich Dumas
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We run a class where the 21.5K motor is the standard and at 10 volts without magnets they can pull 2 amps each. I expect that the 25K motor would use closer to 2.5 amps. If you were to measure the track voltage with a car running you would see that the voltage will drop considerably. The stock power supply is only good for an amp or so.
 

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With both motors being set up the same i doubt you will see any difference.
The performance difference is the higher rpm and 10gcm.
Unless the length of the straight's have changed your not using the higher rpm the new motor has.
You will have to change the gearing to get any benefit of the higher rpm's the new motor has.
 

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Discussion Starter · #4 ·
Thanks a lot guys . The standard gear wheel (34 tooth) is what I have in now. The other gear wheel I have is a 36 tooth. I'm not sure if the gearing reduction resulting from this would be enough to really get the 25 k motor to sparkle.
 

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QUOTE (RichD @ 27 May 2012, 13:33) <{POST_SNAPBACK}>We run a class where the 21.5K motor is the standard and at 10 volts without magnets they can pull 2 amps each. I expect that the 25K motor would use closer to 2.5 amps. If you were to measure the track voltage with a car running you would see that the voltage will drop considerably. The stock power supply is only good for an amp or so.

steveaca,

What RichD said is very correct.

With the stock Scalextric WallWorts, you are limited to about 200 milliamps, or about one tenth of the power needed to make that motor come alive.

A friend of mine had a track using the same power supply and he bought one of the great TSRF cars. When I was driving the car I felt it was 'soft' coming out of the turns. Now this was on the 14.8 volts that was being supplied.

I did a 'test wiring' in of a power supply with 20 amps of current capability. Wow! What a difference that made. The car all of a sudden became a slot rocket.

Think of it this way, the voltage will make the motor run faster under no load. When you put a load on it, the motor will start to draw a loarge amount of current. The current is what will let that motor accelerate hard under a load.

You will see a huge difference between the 21,500 and the 25,000 rpm Slot.It motors once you get a power supply with some grunt behind it.
 

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Discussion Starter · #6 ·
fl slotter,
thanks for those comments. They are very encouraging. I'll try to run the car on a track with better power and look forward to seeing it come alive .
 

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We did notice a small improvement not Slot.it 25k motor. Using two Wallwarts plugged into the powerbase with the switch connecting both power supplies to both lanes not one supply to each lane. Also one can modify the stock controller by using thicker connecting wires (requires new 1/8" / 3.5mm stereo plugs).

Not much difference but cheaper than a new power supply.
 
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