SCX's motors***Updated 10/31/08***, Photos, definitions, and spec's added. Options

[DaveKennedy]

Why not try the SCX Pro gears? They work very nicely. They come in 9, 10, and 11 tooth applications.

[DaveKennedy]

As my Dome are both fitted with 10 teeth pinions, if my engines die, i'm stuck !!

You can do some maintenance to your motor you know to help the life of it.

1. You can make sure it's oiled once in a while.
2. You can take the motor apart and clean the brushes and commutator.
3. Keeping the bearings on the axles greased well will help too because the motor will be under slightly less stress if the parts are all moving well.

I was just looking at the Dome Judd I have an it's got the RX-62 motor which means it's slower than you car with the RX-62C motor, the "C" at the end of the name of the motor is the speed of the motor.

I was given a spec sheet when I visited SCX earlier this year by the design director on that sheet is the following info (no voltage is given but Rob and I are assuming 12 volts).

Motor "numbers":
I'll use the RX-41 and RX-41B for this example.
The first number, the "4" in this case is the armature length and also refers to where the pinion is mounted. So a motor with a "4" is a 50mm shaft with a 9-tooth pinion mounted on the rear of the armature.

The next number, the "1" in this case refers to whether the motor is meant to be used with a motor pod or not.

1. The "1" means a motor made for use with NO motor pod.
2. The "2" means it IS meant to be used with a car with a motor pod.
3. A motor with no numeral means it's for use with a "wire" application like the Pro motors. So the RX-4H is only for use with wires and won't work with the standard "wireless" power system like is used in most all SCX standard cars.

For the RX-62C, the "6" armature shaft is 52.5mm long and is mounted with a 9-tooth pinion at the rear. The "2" refers to a motor pod application and a rated speed (because of the "C" designation) of about 19,000 rpm.

Another example, the RX-81 is a 4x4 motor. The "8" refers to a 73mm shaft (very long) with a 9 tooth at each end.


Motor "letters":
Motors with no letter or an "A" at the end are rated at 16,400 rpm. (Like the RX-41, RX-42, RX-62 etc.)
Motors with a "B" are rated at 18,000 rpm. (Like the RX-42B)
Motors with a "C" are rated at 19,000 rpm. (Like the RX-62C)
Motors with a "D" are rated at 19,000 rpm. (Including the Pro Turbo Plus, and RX-81D which is also called the Pro Turbo 4x4).
Motors with an "E" are rated at 22,000 rpm.
I don't have details for the "F" motors.
Motors with a "G" are rated at 21,000 rpm. (Including the RX-81G)

Older motor have had their names changed to conform to new naming as well. If you have questions about older motors you can ask the rating here.

I'll add photos of each of the motor tab systems in a bit... just for reference.

DaveK

[LanciaB]

Hi dave, thank you for all these informations, very helpful.

I did not saw two engines on your list : Pro Speed and Rx91.

I use to break all my SCX engines during at least 6 hours @ 4.5 volts (3 is too slow) then open , clean and lube as you describe it.
I lube very lightly as i burnt (in my SCX youngness) a rx91 on my Repsol Delta due to excessive lube, and at this time i did not know SCX cans could be open and cleaned so easily.
Since i know this, i rarely buy other brand's engines, that can not be opened for maintenance.

I was quite surprise to see on other topics, that the Pro Speed specs were similar to the Pro Turbo +.

On my track, that has no long straights (3.5 m ) there is no difference, the Pro Turbo + seems even more faster to take revs.

Do you concur ?

For the Pro Gears, these are not well distributed here, i can only find crowns, not pinions. So i buy Slot-it ones.

[Robert Livingsto...]

Dave forgot to mention that the spec for E and G motors is respectively 22,000 and 21,000 RPM at 14 volts, which makes a big difference. The RX-42E in the Club Porsche is supposedly the same motor as the Pro Speed in the Audi R8; rated 19.6k at 12 volts.

As for the washers and spacers on the rear axle, mine don't move at all against the gear hub. The only friction is side thrust against the inner surfaces of the bearings, running against the trued, polished ends of the brass tube spacers. Of course it is oiled (not greased). The car in the photo is very fast.

[DaveKennedy]

I thought I'd post photos of all the different motors I have on hand.

The "4" family:


The two 4x4 motors I have:


Shown below with notations on the photo for each application:

I was honestly surprised to see the RX-44 (shown below) which I didn't know existed. I pulled it out of an SCX Digital F1 McLaren. The power-pick-up-tabs are bent backwards because of the small size inside the Digital F1 car. They pick up the power from small contact patches inside the Digital F1 car.


A Pro Turbo in an old SCX Arrows F1 that I used to race all the time:


The Pro Speed motor (used for wire application and comes with 10-tooth pinion):


The F1 motor (which is a non pod), shown with the RX-42B (for a pod):


The new RX-4H, 25,000 rpm motor:


The RX-62, note the longer shaft (maybe tough to see I know).

[LanciaB]

Hi dave, I may add some other motor pics that you were not showing :



First a very strange stuff : a 4x4 motor, no mark on it, put on a Toyota Corolla, that has either connection for strips AND wires.
That car is a curiosity anyway, as its 4 bearings are free to play in the chassis, giving flex to the axles. Very good system anyway, too bad it was not set on other AWD WRC cars.




This is the first version of 4x4 RX81 engine. Notice "small" lettings RX-81.




This is the 2nd version of the RX81. More powerful, more revs, more torque. You can recognize it as it has bigger RX-81 lettings.



This is the Pro Turbo + engine, just a bit more powerful than the Pro Turbo. I solder two wires on it tu use it on RX42 floating pods without removing the front on the engine, i just put the wires under the connectors..keeps floating and increases electrical conductivity.




This one is an old RX4, mounted on my BMW M1 and Lancia Stratos.




This one is Pro Turbo 4x4, the AWD version of the Pro Turbo +.




This engine, as i know, was only put inside the Lancia Delta Integrale. 19000 rpm as i know. Planned to be inside the Delta S4 either.



And at last, here is the 62c that is inside my two Dome.

Notice that NONE of my motors is labelling SCX, they are all TECHNITOYS.....french particularity ?

Dave, do you think we have all motors here ?

[V8Vantage]

So the biggest difference between an RXn and an RXn<letter> is that the length of the windings is quite a bit shorter on the un-lettered motors - except for the Rx-91 which appears to have the long windings... But it should be easy to spot if someone's put 'B' spec innards in a 'non-B' can to try to fool the scrutineers and get an unfair advantage.

There also appears to be a small visible difference between the 'B' spec and say the Pro Speed in that the winding holder has more and more tightly spaced grooves on it. I wonder if also the clearance between the armature and the in-can magnets is smaller in the Pro Speed.

Talking of in-can magnets, do we know of any differences in their strength/size between the different flavours of motor. I guess the brush timing is about the same?

And are there differences in the armature bearings?

Thanks for the info and pictures though!

[LanciaB]

V8, the RX91 seems to be a sort of alien in the SCX motors....i gess it's name should have been rx81b as it seems to have the same specs...

....by the way i don't see the need of so much different motors.

It should be : 41b for no pod, 42b with pod on most of the 2 wheel cars ; 81B on AWD ; and maybe a 82h/42h/4h for "pro" cars, and aftermarket sales.

That would be more simple and effective. Why continuing to sell 41 or 42 motors ??

Let them to JIADA or other Chinese poor copies !!

[DaveKennedy]

Wow Lancia thanks! Good photos and I sure don't think we have ALL the motors yet for some reason....

There are several things that makes a "B" a "B", the thickness of the plates on the armature stack has to do with it. Also the number of windings and the thickness of the wire used in those windings. I have those spec's and I will post them. Yes, the magnets are also different... I have those spec's too.

Tecnitoys is the company name, SCX is the brand name they use outside the Spain, Portugal, and Mexican market. Because SCX uses the name "Scalextric" in Spain they might have used the "Tecnitoys" name on the motors I guess. Motors marked with the "Tecnitoys" name are older motors from what I have seen. None of the current cars have that name on the motors.

[DaveKennedy]

That would be more simple and effective. Why continuing to sell 41 or 42 motors ??

I think it's because in certain cars a slower motor is appropriate. Do you know the Ninco Classic line? They used to use the NC1 motor in them, this is a much loved motor (especially here in the US). And I think it's fine to have a slow motor in some cars. Further the RX-42 is the motor that's used in the first version of the SCX-Digital system cars. The "V1 Chip" as it's called works with the RX-42 only.

[Robert Livingsto...]

The SCX spec sheet shows that E coded motors have slightly stronger magnets than the others (5.7% stronger!). Whether the E code applies to the Pro Speed and the Pro Speed Double Rally is unconfirmed. The only motor sold with an E is the RX-42E in the Club Porsche. If I had an RX-42E to measure, I could be more sure of the differences (or not) between E and Pro Speed.

The H series (RX-4H) is not on the spec sheet because the spec sheet was written before the RX-4H was developed.

There is no information that indicates that SCX motors vary in timing from model to model, other than normal production variation.

I can only guess at why SCX has taken the road of a different motor for every sub-group of cars. They appear to be changing the performance specs in very subtle, almost undetectable steps. I can understand (possibly) the need for variations in the length of the leaf-spring contacts, or the shaft lengths, but all those different windings, and armature-stack variations? Sometimes the normal production variation between same-type motors is bigger than the difference between different types.

On the other hand, SCX appears to be paying attention to the driving feel of the cars, perhaps more than the other manufacturers. That can be a good thing!

[LanciaB]

Dave, as i'm not a digital user, i didn't remember the need of rx42 in most of digital cars. Shame on me.

Robert, I agree with you, SCX is the brand that has listened the most, during these last years, to the requestings of the users/bayers.

People wanted more revs to fight against the Scalex cars --> B versions
People complained about poor quality cars --> high improvement since the firsts GT's (550, DBR9...)

But SCX has kept what makes this brand different, and innovative : powerful lights, no cables inside the cars, floating pod, good no-axle frontwheels (so it can be done, Mr Barrios !!) ....and low price !

The only things that are to improve again, for me, is the light protection (burns with voltage up to 15v) , the Quality Controls (too much cars come with broken wheels, non-straight axles..) and the tyre compound, too hard. Maybe so changing the standard gear ratio to 10/27 for more speed, SCX motors have more than enough torque to support this.

Then, Slot It and others are.....dead !! (if the price stays same of course !!)

Bruno.

[V8Vantage]

For the lights burning out at higher (e.g. Hornby) voltages, there's a simple do-it-yourself fix: carefully cut one of the strips to the front lights where it won't fall out - usually above the front axle - and solder a 100ohm 1/4watt resistor across the gap. It drops the voltage sufficiently so that the lights stay bright but don't blow. The rear LEDs don't seem to have any issues anyway. One word of warning - if you have a car with silver-coloured strips in the body (like my Solberg Subaru with the extra front lights), trying to attach solder to those strips is just about impossible. I've just wrapped the resistor wire round loads of times to make a firm but dry joint.

Also, the latest 2008 cars that are V2 Digital-ready have a little 'analogue board' where the V2 chip would sit. That appears to have voltage overload protection for the front lights, so things like the Pug 908, Porker GT3 etc. don't blow their front lights on other manufacturers' higher voltage systems.

Back on motors...

It's interesting what Dave says about the different spec motors for different types of cars. I'd agree -- but then my Alpine 110 came with a B-spec motor and I think it was my Audi DTM that didn't...

Now even though the B was a 41, I was able to get good contact in the Audi's pod-based chassis. Bizarrely enough, the shorter, more vertical chicken legs from the motor restrict pod roll just enough to stabilise the car better. No having to solder or glue the motor in, so it's still easy to swap. And the Alpine's non-pod Classic chassis is totally compatible with the 42's longer legs.

I totally agree that SCX have listened to and acted more on comments from its customers that any other of the majors. There's only those two Italian boutique companies of Slot.it and NSR that are right up there with SCX. After all, there's an SCX-Pro pod that can take motors of a type that SCX doesn't even produce!


There's an upside and a downside to so many different sorts of motors: there's the opportunity for getting very well-matched motors and cars (not too fast in the classics, fastest in the Pro LMP cars, best torque in the Pro Rally cars, etc.). The downside is to encourage (and have customers find) stockists to take a wide range of replacements. Fortunately motors (provided they're not over-oiled) are extremely reliable these days, so maybe that's not such an issue anyway...

But it's really excellent to know about the different types and their characteristics and so sort out the 'best' application for each variation. Thanks all!

[Robert Livingsto...]

I have seen only one RX-91 motor in a car; that was in a Norwegian guy named "356 Speedster"'s entry in GT2 class of the RAA proxy race this year (it was not an SCX car). A tachometer test of the motor at 12.0 volts showed 7700 RPM at the rear axle, with 12:32 gears. The actual motor was turning at 20,533 RPM. Since the motor has no letter code, one would assume it is an A-wind, but reality shows it is about the same as a Pro Speed, closer to D- or E-code. A note on the spec sheet Dave obtained from the SCX engineering dept. shows that the RX-91 is actually an F-code armature, so it should have been labeled RX-91F. But it wasn't. F armatures are mysteriously unrated on the SCX poopsheet. They have a long shaft with pinions on both ends, for 4wd.

[LanciaB]

Thank you for this info Robert.

In fact the RX91 is even more powrful than the Pro Turbo 4x4 or Pro Speed 4x4.

But as far as i know, this motor is quite fragile and does not love too much lubrification.

A as saw on Altaya lists, it's going to get inside the new Lancia Delta S4 as well. Maybe the chassis is the same as the Integrale, I don't know.

Strange to see that SCX US techs, don't seem to have any info on the Altaya prods ??

Do you know any way to get these Altaya prods, inside or overseas ?

......that's the kind of service that shall be due to SCX Worldwide Club members, don't you think ?

[Robert Livingsto...]

I found an e-mail in my files, relating to a test of two SCX motors a couple of years ago:

"The RX62C turned 20,218 at 12v.
The Pro Turbo Plus turned 20,340 at 12v.
These motors are essentially the same, as far as no-load RPM goes.
But the RX62C has a longer armature stack, which is often associated with higher torque.
Armature winding resistance for the Turbo Plus is 1.9 ohms, and is 2.2 ohms for the RX62C. All other factors being equal, the lower resistance motor (Turbo Plus) will draw more amps, run hotter, and will put out more power. However, the difference in power is probably minor."

Comparing to the SCX official data sheet, the Pro Turbo Plus is a D armature, rated 19,000 RPM/12v. The RX-62C is a C armature, also rated 19,000 RPM/12v. So, these two motors were revving 1200-1300 RPM over rating. Torque is rated 158 gcm for the D, and 179 for the C, by SCX. I think those ratings are too high. Again according to the SCX data, the size of wire differs in the windings, as do the number of windings, number of plates in the stack, and the thickness of the plates. Just to confuse things further, the C rated armature was sold in the Pro Turbo as well as RX-62C, distinguishing the Pro Turbo from the Pro Turbo Plus. So, the Pro Turbo Plus would the the same as the Pro Turbo at no-load RPM, but have more torque, so it would accelerate faster under load.

Torque ratings for SCX motors from the official data sheet:

A: 143 gcm/12v
B: 153 gcm/12v
C: 179 gcm/12v
D: 158 gcm/12v
E: 165 gcm/14v (?)

A sample A was tested by Davejr at 77 gcm/12v, and a B at 97 gcm/12v. These figures are 54% and 63% of the SCX-rated value.
SCX has announced 140 gcm torque for the Pro Speed, but I measured only 123 gcm/12v, on test, or 88% of the claimed torque.

[ddyke]

#1 Do you have this motor? If not PM me and I will send it to you.



#2

The motor you sent me does very credible laps. We got it to a 10.39 practice lap and 10.7-10.9 race laps. We are now installing it in another club member's car to test.

[DaveKennedy]

Now that's interesting. I don't remember seeing a painted motor before....hmmmm.... keep us updated Dan.

[Robert Livingsto...]

Dan, if you send it to me I can test it for RPM, torque, and winding resistance. I can even return it to you if you want it back!

Where did this motor come from?

50 Morris Rd
Woodbridge CT 06525
USA

[ddyke]

It is from a blue Ferrari 333sp. Cincyslots had it and we wanted the body.

Dan

Dan, if you send it to me I can test it for RPM, torque, and winding resistance. I can even return it to you if you want it back!

Where did this motor come from?

50 Morris Rd
Woodbridge CT 06525
USA