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Circuit Owner
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Discussion Starter · #1 ·
Having trawled SlotForum for the answer and not finding it I think it is time to ask this question.

I have a pair of C.7 Mini Coopers. Both appear almost identical mechanically and were bought as part of a job lot from a guy who had them as a kid in the 70's.

The glaring difference is that, although both cars are fitted with Johnson motors - one has copper coloured windings and the other has green windings.

Can anybody tell me if there is a difference in performance between these motors? They seem pretty close on my Sport layout BUT I will be rallying one of them next week and wondered which motor I should be using.

Thanks
 

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Premium Member
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Hi Mr Modifier,
The last Scaley c7 Minis (of the 70s) had the Johnson 111 Small Can motor fitted. Within the tolerance of manufacturing difference performance would have been similar when new. However, after all these years wear & tear might make a difference between your two cars performance now.
The slightly later Mabuchi small can motor sometimes had green windings which made no difference to performance.
cheers
Kev
 

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Jim Moyes
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Green windings would suggest an MRRC version of the Johnson to me. What colour and material is the pinion......erm.......Mr.M?
 

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Circuit Owner
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Discussion Starter · #4 ·
Hello both,

Loosesalute - these are definitely Johnsons. I have a Mk1 Escort with a Mabuchi with green windings.

Mr. M - the pinions on both Minis are mid-to-dark grey plastic (nylon?) and not the usual white Scalextric offerings. The rear wheel bearings on both Minis are white.

The Mini with the green windings has black spacers on the front axle (like a standard bearing but with one side without a flange). The Mini with the plain copper windings has white bearings used as spacers for the front axle.

Both have yellow contrate gears.
 

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Put a pic up of the Minis please Mr Modifier?

What era are you referring to Mr M? I`ve just checked a lot of my Airfix & Airfix/ MRRC motors from the 1970s to 1980s & the windings are either a light copper or dark reddish colour .

Quite a few of my cars with the Mabuchi small can do have green windings, with no difference in speed.

Cheers,
Kev.

Mabuchi small can with green windings.
 

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Premium Member
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Hi Mr M,
There is almost certainly no difference in the actual wire used on these different coloured windings.
The difference is purely in the insulation coating used.
Back in the '60s I worked for a company that manufactured motors of various types, mostly for the military, and, from memory, the different colours indicated the following.

Brown/copper colour = standard insulation (shellac I believe).
Green = high temperature inulation.
Pink or red = self fluxing insulation. ie. you didn't need to scrape off the insulation before soldering as the coating had a flux in it.

None of this made any difference to the performance of a motor except that the green insulation could withstand significantly higher temperatures than the other two. With a Johnson motor the endbell or commutator core would melt long before heat would affect the wire insulation of any of these coatings.
Burnt out windings were usually caused by the insulation being rubbed through against the armature stack, causing a short circuit and consequently excessive current consumption, as most of these motors had no protective coating on the stack.

In modern motors the insulation is of much higher quality, and can be almost any colour, and armature stacks are powder coated to prevent any possibility of a short circuit.

So sorry but the colour of the windings is unlikely to give any indication of performance.
Cheers.
****.
 

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Jim Moyes
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QUOTE (Mr Modifier @ 13 Apr 2012, 22:46) <{POST_SNAPBACK}>Mr. M - the pinions on both Minis are mid-to-dark grey plastic (nylon?) and not the usual white Scalextric offerings. The rear wheel bearings on both Minis are white.

Keep hold of those pinions, I've never had one of those split. That's one problem with Johnson motors - pinions. The original white ones are invariably split and the replacements that Scaley produced with the collar seem to not like the extra heat of the Johnsons and lose grip on the motor shaft.

I'm probably wrong about MRRC motors having green windings, Kev. It's just that I put together a set of 4 C7 Minis for a club class many years ago and I had some brand new motors from MRRC which I thought I had used. I checked them last night - but couldn't get back on the forum
- and one has green windings and a brass pinion so assumed from that it was an MRRC motor. But now I have checked my remaining stock of new MRRC motors they have copper windings.

I have found two C7s with green windings on the shelves, one has the black front spacers and one has white. I forget how many I've got. If I see them cheap at swapmeets I can't resist them - I bought two at the last Orpington swapmeet from Barry Smith and I bought a parcel of 4 Minis off Ebay a few weeks back.


Going back to the 4 I used for my club class - they were all very equal in performance and only one has green windings, so I guess it's not an issue. Perhaps Scaley ordered a batch of motors and could only get the green winding ones for a while, so absorbed the extra penny or two into the cost until they could get the copper ones again.
 

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Circuit Owner
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Discussion Starter · #10 ·
Thanks for all your help gents.

I am going to run one of these in the Classic class at a rally meet so I wanted to build up the best mini I could from the two sets of parts I have. It looks like I can use either motor.

I appreciate the help.
 

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Hi,

I think the green winding version of Johnson 111 was used in some Scalextric cars 1970- circa 1973-74. I have seen these motors only on the first '111 cars': Dart GP (C20), Cougar Sports (C21) and early (narrow tyre) Scalletti Arrow (C23). End bell of this motor was white plastic and material of pinion was brass. According Scalextric Service Sheets the code number of this motor was W.1603.

The later version (W.2030) launched (probably) 1974. The color of windings was something like light orange/copper. I have also seen red windings. End bell was black plastic. And plastic pinion was dark gray (later white). I have only seen W.2030 version in cars produced 1974:

C.007 Mini
C.012 Shadow
C.013 Tiger Special (according some factory sources this car has been also produced with W.1603)
C.015 Ford Mirage
C.016 Ferrari P4
C.017 Lamborghini Miura
C.023 Scalletti Arrow (wide tyres)
C.052 Ford Escort Mexico

I don't know if in these 'Super Formula Cars' were used RX motor instead of 111 still 1974:
C.025 Ferrari 312 B2
C.026 March-Ford 721
C.050 JPS Lotus

Mr Modifier: If you like to build up the best C.7 Mini I recommend RX-motor instead of Johnson 111. Especially for twisted tracks without long straights.

Regards
 

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Circuit Owner
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Here they are...



As you can see - green windings and black end bell.

Ignore the black contrate gear, axles and wheels on the red mini - these are brand new as the old axles were rusty and the yellow contrate was worn; this car will be rallied at Wye Valley club on Thursday so I wanted it to have a chance of making it through the night! The yellow one is also going to Wye Valley but will not compete.

The yellow mini is stickered number 2 on the sides and the red one number 6.

The chap I bought these from as part of a job lot had them since he was a kid and as his partner had produced 3 little girls he had given up all hope of ever using it again! The condition of the cars I bought from him are best described as "unloved". I got the impression he played with them but didn't have enough mechanical nouse to fiddle with them. What I am saying is that I believe there is a low chance they were upgraded and the Minis were probably part of a set.

I was just curious about the difference in the motors.

In case you were wondering about the tyres - they are home made - Shore A50 fronts and Shore A20 rears. And yes there are a few air pockets (I have it sussed now) and no - it doesn't seem to affect performance - these beasts fly around my Sport track like they have magnets in!
 

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Hi Kai,
The very first Lotus 72, March & Ferrari F1 cars did come fitted with the RX motors.

Are they solid coloured Minis or chequered roof versions Mr Modifier?
The solid colour Mini was only available in 1973, & a very few early ones had the RX motor fitted. The original chequered roof version was made between 1974 & 1975.
Your cars have had the guides changed at some point in their life.
BTS Mouldings do an excellent repro bumper for your yellow Mini, it`s well worth getting one.

Nice tyres. How much dosh do you save going DIY?

Cheers.
Kev.

For your ref.
Two solid colour Minis. These two are rarer still because they were made in France. Deeper red colour. Left hand drive & no co-driver. Different crash helmet. One car has the unusual French Scalex dish wheels, the other has standard Scalex Mini wheels. The chassis & guide were slightly different to the UK cars.



Chequered v solid.



A very early UK flare arch Mini with the RX motor fitted. Note the ribbed tyres which were originally fitted to 1970s Minis.

 

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I have a French C27 Lotus Turbine, the motor is the first type described: Green winding, white endbell. The contrate is metal and the performance dreadful! Even after zapping (with neodyms, usually works) the magnets seem weak (a rough check with a compass) and it only does about 12000 RPM on the tachometer.
 

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QUOTE (Mr Modifier @ 17 Apr 2012, 16:32) <{POST_SNAPBACK}>Here they are...



As you can see - green windings and black end bell.

Ignore the black contrate gear, axles and wheels on the red mini - these are brand new as the old axles were rusty and the yellow contrate was worn; this car will be rallied at Wye Valley club on Thursday so I wanted it to have a chance of making it through the night! The yellow one is also going to Wye Valley but will not compete.

The yellow mini is stickered number 2 on the sides and the red one number 6.

The chap I bought these from as part of a job lot had them since he was a kid and as his partner had produced 3 little girls he had given up all hope of ever using it again! The condition of the cars I bought from him are best described as "unloved". I got the impression he played with them but didn't have enough mechanical nouse to fiddle with them. What I am saying is that I believe there is a low chance they were upgraded and the Minis were probably part of a set.

I was just curious about the difference in the motors.

In case you were wondering about the tyres - they are home made - Shore A50 fronts and Shore A20 rears. And yes there are a few air pockets (I have it sussed now) and no - it doesn't seem to affect performance - these beasts fly around my Sport track like they have magnets in!

A lot of these motors will run better backwards depending on how "off" the comm timing was set from the factory. Try running the motor backwards by swapping over the wires to the guide and then flipping over the crown gear. See if the car goes better with the motor running "backwards". Easy check, should only take you a few minutes to test.

cheers
rick1776
 
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