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Discussion Starter · #1 ·
Hello!

Getting deeper into this great hobby, I am wondering what the definition of Magnatraction is. The search-function was no big help.

Is it in general the magnetic force, that keeps the slot car on the track? Or is it a certain type of magnetic force, i.e. by the magnets in a motor? In that case, a slot car with removed magnets can still have magnatraction? Scalextrics uses that as a special feature in the product descriptions wich seems to be trade marked.

Any hint will be welcome.

Thanks in advance!

Markus
 

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Markus,

Very simply, it is the use of specific magnets to hold the car on the track, which means that the contact rails must also be in a magnetic material.

Certain motors may also have an inadvertant magnetraction effect, if the magnets are open, and the car is low enough to the track. With most modern "can" (Mabuchi) type motors, this effect is very slight. It can be very significant on older open-frame type motors (as used in older model trains).

Magnetraction first became popular in HO slot cars, where the magnets on the popular Aurora AFX cars were held separately in the chassis, and I believe that somebody lowering them, perhaps for other purposes, realized that there was a significant magnetic effect.

Mr. TSR can give you some more info on this...

Don
 

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Taking into account that all electric powered slot cars will have some form of mild to profound source of magnetic downforce produced by the electric motor, my definition of "magnatraction" is any form of additional devices added to a chassis which produce magnetic downforce to increase levels of grip.

"MAGNATRACTION" was the definition used by Scalextric to "market" the use of additional magnetic devices to the public.

I don't think the term is one used in scientific circles, hence failure of a search on the internet to give you a satisfactory definition.

Thats the beauty of SLOTFORUM! Ask and ye shall find!
 

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QUOTE (Ian H @ 8 Mar 2012, 14:18) <{POST_SNAPBACK}>Taking into account that all electric powered slot cars will have some form of mild to profound source of magnetic downforce produced by the electric motor, my definition of "magnatraction" is any form of additional devices added to a chassis which produce magnetic downforce to increase levels of grip.

With the "development" of the 1/32nd motors and offset motor brackets in the last couple of years, and with some years of "rule making" under the belt I would skip the "additional devices" in the definition.

Magnatraction= amount of pull of a slotcar on a metal surface, usually measured in grams.

Which is why most rules in the Netherlands specify a max number of grams of magna traction and is usually measured like this


Measure the weight of the car with the car on its side on the scale = (74 gr) reset the scale to zero....


place the car over the metal bar (simulating the slot) and presto, the stock Fly magnet gives an extra 228 grams of "downforce"

Which BTW is also why the magna cars tend to "fly" off the track once they go over the limit


(images courtesey of http://porscheharry.blogspot.com/2010/02/m...t-marshal.html)
 

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The term magnatraction was first used by Aurora in the early 70s, Aurora sold a whole range of 1:64 Magnatraction cars, they differ from the earlier AFX cars in that the motor magnets are lower in the chassis and exposed underneath just where HO track rails are and was done deliberately by Aurora to make the cars corner quicker. This is completely different to the seperate traction magnets now seen on slot cars, I believe the first company to fit seperate traction magnets were Tyco, who beat Matchbox to it by a matter of weeks.
As far as I know Aurora got the idea from what HO racers in the US where doing at the time.
 

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QUOTE (Ian H @ 8 Mar 2012, 13:18) <{POST_SNAPBACK}>Taking into account that all electric powered slot cars will have some form of mild to profound source of magnetic downforce produced by the electric motor,
That only works where there track is attracted to a magnet. For example there will be downforce when running on plastic track with mild steel rails and on routed tracks using "magnabraid".
There is no magnetic downforce on tracks that are not attracted to a magnet. For example there will be no magnetic downforce on routed tracks using copper tape or copper braid.
 

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A young fellow by the name of Tom Bowman had been playing around with seperate magnets on his HO cars, and Aurora saw and took the concept mainstream. Tom never got full credit and recognition, and some have tried to claim the acheivement for themselves subsequently.

Amazingly, Tom still races HO to this day, and makes awesome resin bodies under the BRP name.
 

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QUOTE (300SLR @ 8 Mar 2012, 13:57) <{POST_SNAPBACK}>There is no magnetic downforce on tracks that are not attracted to a magnet. For example there will be no magnetic downforce on routed tracks using copper tape or copper braid.

I think Ian can be forgiven for not being specific about the rail type, we all got what he meant.

It could be that you are wrong anyway, just as with the tree in the forest thing one could argue the magnets create a field even in the absence of anything for it to react against.
 

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Thanks for the additions guys, and that looks like a very good system Tamar!

For what it's worth, I found the US model train manufacturer Lionel using the term "magnetraction" back in the 30s or 40s, I think, as an aid to hill-climbing for its choo-choos... I'll have to find the exact quote and date though, but it might be on the Net somewhere.

Don
 

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QUOTE (montoya1 @ 8 Mar 2012, 14:07) <{POST_SNAPBACK}>I think Ian can be forgiven for not being specific about the rail type, we all got what he meant.
I wasn't criticising Ian, simply adding more information to the point he made.
It's rare indeed for anybody to say all that could be said on a topic.

I don't doubt you knew about that point already, but not everybody who reads these posts is as knowledgeable as you are. I recall several posts on other threads from SF members who didn't understand that point.

QUOTE (montoya1 @ 8 Mar 2012, 14:07) <{POST_SNAPBACK}>It could be that you are wrong anyway, just as with the tree in the forest thing one could argue the magnets create a field even in the absence of anything for it to react against.
The field will be there in the absence of anything for it to react against, the downforce won't. My post was about downforce, (and was correct) it didn't mention the field.
 

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Fair enough. If it is a bullet-proof definition we are looking for then the motor magnets and rail type have to be factored in to the wording, granted.
 

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QUOTE (Mars @ 8 Mar 2012, 13:11) <{POST_SNAPBACK}>Scalextrics uses that as a special feature in the product descriptions wich seems to be trade marked.
A bit of googling reveals Magnatraction was registered as a trade mark in the UK by Hornby Hobbies on 30 March 1990. Apparently the registration expired on 17 September 2008

Magnatraction seems to be used by AFX although I couldn't find a record of it being registered.

(If anybody is interested, Magne-traction was registered as a trade mark in the US by Lionel on May 19, 1953, they seem to have used it on their model railways at the time.)

There seems to be some doubt if the definition of Magnatraction should include the magnetic attraction of the motor or just of additional magnets.
In the absence of any authority to decide, who is to say which is right?
For many purposes it doesn't matter which is right. When it does matter, doesn't it makes sense to make it clear which you mean to avoid misunderstandings
 

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The manufacturers will use it for their ends, with no compatibility, but if we the end users want a working definition then we have to factor in the motor attraction, IMHO.
 

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The net effect is what can be handled. Ie whatever magnetic downforce there is will effect the car's handling.
After that it's up to setting the magnets up to be as effective as possible.
As an example the one managing to place his motor lowest in the Ninco championship wins.

The weight variant to measure magnatraction is easy, but not very precise. Not very precise at all. And perhaps more important, it's expensive.

That steel plate is a magnet all by itself. It's not good at saturation (the ability to keep being magnetised) but it still is a magnet, and thus either add to the magna measured, or deduct from it.
There's also a matter of where the car is on it. It measures one thing of far front, another when far back.

But if using a few restrictions it's a help.
Restrictions as pole direction, placement in car, motor variants (angle, location, type, rotation) etc. Things to minimize effects of iron being used as medium for weight measure.
And there's also the matter of how the plate gets magnetized from car to car being measured.
 

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QUOTE (dgersh @ 8 Mar 2012, 13:16) <{POST_SNAPBACK}>Certain motors may also have an inadvertant magnetraction effect, if the magnets are open, and the car is low enough to the track. With most modern "can" (Mabuchi) type motors, this effect is very slight. It can be very significant on older open-frame type motors (as used in older model trains).

Nothing inadvertant about it IMO, but for me yes Magnatraction is a compund word meaning a Magnet is used in order to increase Traction but the effect is evident in cars even without a specific magnet installed for the purpose.
 

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Phew!

I would have thought it obvious from my post that I was referring to the magnetic downforce exerted when the chassis is running on steel rails.

I must be more specific in future . . . .

Anyone fancy a pint?
 

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The word "Magnatraction" is marketing speak for magnetic traction improvement. Various firms lay claim to its first use as others have noted. Incidentally, Hornby/Triang were using it on their choo choo trains long before their sister company of Scalextric decided to make a big thing of it.

In practical terms it means adding a strong magnet to slot cars in order to hide deficiencies in other parts of the product. Why spend time, effort and money on building a half decent chassis with round wheels and grippy tyres when you can simply bung a magnet in it and glue the car to the track?

Magnatraction is also the toy car version of aerodynamically produced down-force in full size cars. Both have the same effect - increased cornering speed at the expense of slower straight line speed. Both also have the same defect - very little warning that the limits of adhesion have been reached followed by a very large accident.

I don't like either of them but at least I can remove the magnet from a slot car - I doubt you can uninvent aerodynamic down-force.
 

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Discussion Starter · #19 ·
Thank you all VERY much for your answers! Very interesting, very entertaining! I hope, one day I get the chance to pay back what I got from you!

Since then, stay on the track (wether with or without magnetic traction
)

Markus
 

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In my opinion, 'Magnatraction' is a term used by Scalextric to denote cars which are fitted with an additional magnet (ie. not the motor magnet) to aid handling. The word has gradually come into general use for all brands in much the same way as 'Hoover', which many people don't know is a brand name and call all vacuum cleaners by.
 
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