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Apologies in advance for the long post...but I have been tearing my hair out over this stuff for the last couple of days!

OK, let's start with the problem I had with a Scalextric Porsche Spyder. I have three Scalextric LMP cars in total:

C3015 Porsche RS Spyder
C3188 Aston Martin Lola
C3195 Peugeot 908 HDI FAP

All three cars are chipped with the C8515 plug for use on my permanent digital layout.

At the weekend I was racing with my brother and my nephew and couldn't for the life of me work out why the Porsche RS Spyder was so handling so badly. The Aston and the Peugeot were a close match for each other but the Spyder was way off the mark. It was coming off so frequently I ended up taking it off the track and we reverted to racing GT cars for the rest of the day.

I have had the Spyder for a while, I got the last one available from Modelzone last year, but only got around to racing it for the first time the other day as I had only recently acquired the Peugeot 908 and Aston Lola to facilitate races of 3 LMP cars on my layout.

On closer inspection, after we finished racing, the Porsche Spyder appeared to have little-to-no magnetic downforce. This was very noticeable when lifting the car off the track by holding the rear part of the car or the spoiler. Checking the other two cars, you could feel the magnetic downforce when lifting the car off the track at the rear.

I took the Porsche Sypder apart and removed the magnet. It still had magnetic properties for sure but clearly it wasn't working properly in the car.

I then took the W8475 magnet out of the Aston and put it in the Porsche. This appeared to be identical in size to the magnet that was in the Porsche and fitted perfectly in the slot.

The difference was night and day.

How can this be so? Is it possible for Scaley magnets to lose their magnatraction, even though they clearly still have magnetic properties?

Also, I looked at the service sheet for the Scaley Porsche RS Spyder, couldn't find one for C3015 but the sheet for the others mentions W8449. This though is a pack of magnets of different shapes and sizes - does it include the W8475? I presume it must do as this magnets fits the car perfectly.

But when I look around on the web it seems W8449 is no longer available although W8475 seems easy enough to find.

After the problems with the Porsche, I then started checking some of my other cars.

To my shock, the McLaren MPC4-12 (C3200) and Bugatti Veyron (C3199), both of which I recently acquired but hadn't run yet, seem to have absolutely zero downforce, even though they are obviously shipped with magnets in them. They don't handle very well at all.

Looking at the service sheets for these two cars, both have W8695 shown as the replacement magnets but everywhere I look I see that these magnets (which are thinner than the W8475 magnet) are not available any longer from Scalextric! Why is that so, when these cars are relatively new?! That's nuts!

The W8475 is not an option as it's too thick for the McLaren and Bugatti.

...which leads to my next question: what about stacking magnets? Is it OK to stack a smaller magnet on top of an existing one? For example, I've seen 20x6.1.5mm magnets on eBay, which would sit on top of the thin W8695 bar magnet in the McLaren and the Bugatti. Would this be OK to do?

I've also noticed that my Scalextric Maserati MC12 (C2904), which uses a completely different type of magnet (W8902), also seems to be lacking in downforce. These magnets seem easier to find, but I still don't understand how these magnets are losing their magnatraction?

And finally...

A question about putting two magnets in a car with two slots - for example, I have 3 Scalextric BMW 320 Si touring cars, they take the W8475 bar magnet and have two slots for them. I do find these cars somewhat flimsy and lacking in weight so I was thinking of adding another magnet into the spare slot.

Would it be OK to add a second magnet in these cars so that both slots are occupied with W8475 bar magnets?

Any comments and suggestions (apart from cutting holes or other similar suggestions - please) greatly appreciated.

And if my questions can be answered that would also be hugely helpful!
 

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One petunia in a field of onions
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One of the issues is a simple case of magnets. Two different magnets of same size, shape, weight and compound can have variances in magnetic force. An impact shock can be enough to weaken the force offered by a magnet.

The only real way to match magnets would be to measure the magnetic force of a bunch of them and select the closest three to use in your 'matched' cars.

Embs
 

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Discussion Starter · #3 ·
QUOTE (Ember @ 23 Apr 2012, 15:08) <{POST_SNAPBACK}>One of the issues is a simple case of magnets. Two different magnets of same size, shape, weight and compound can have variances in magnetic force. An impact shock can be enough to weaken the force offered by a magnet.

The only real way to match magnets would be to measure the magnetic force of a bunch of them and select the closest three to use in your 'matched' cars.

Embs

Thanks. I didn't realise they could be weakened by crashes.

And how I do measure them? Is there a simple and easy way to do it?

Also, what about stacking magnets and / or putting additional magnets in the spare slots?
 

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Circuit Owner
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More magnetic downforce does make the cars stick better BUT too much down force will slow the car down on the straights and puts more strain on the motor as it has to work harder to drag the car around the track.

Packs of strong magnets are available on ebay - I bought a load to put in my Taurus NASCARs then decided they were more fun without magnets (much slower but needing a much more skillful driver). Just measure carefully and search for neodymium magnets.

Have you thought about taking the magnets out, adding a little weight to the nose and buying some urethane tyres?
 

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I measure the magnetic downforce on my cars using a set of scales which have had a hole cut in them and replaced with a metal plate which has been packed so that the metal plate is level with the top of the scales but does not touch the weighing platform, another slot is cut opposite for the guide. I can use the scales to measure the weights of cars and also the magnetic attraction. This isn't an exact science but it does let me know roughly how even the magnets are in the cars. I have 4 of the Peugeot 908's, the Aston Martin Lola and also the Porsche Spyder. My 2 fastest (lap times not straight out speed) Scalextric cars are 2 of the Peugeots which have a similar magnetic downforce, although one has a motor with a bit more go, the other 2 have less of a magnetic downforce thus don't stick to the track like the others. You will find that not many of the scalextric bar magnets are the same, some have a huge amount of downforce while others seem to have little if no downforce. The gap between the chassis and the rails can also give you a different effect as the magnet can be closer to the rails or further away resulting in different magnetic downforces.

Matt
 

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Don't mess around just get a pack of magnets. Yes you can stick other magnets on top to increase the strength. But really stick them as the magnetic force may not be sufficient to hold them together in a crash
 

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Discussion Starter · #7 ·
QUOTE (Mr Modifier @ 23 Apr 2012, 15:36) <{POST_SNAPBACK}>More magnetic downforce does make the cars stick better BUT too much down force will slow the car down on the straights and puts more strain on the motor as it has to work harder to drag the car around the track.

Packs of strong magnets are available on ebay - I bought a load to put in my Taurus NASCARs then decided they were more fun without magnets (much slower but needing a much more skillful driver). Just measure carefully and search for neodymium magnets.

Have you thought about taking the magnets out, adding a little weight to the nose and buying some urethane tyres?

Yes, I have thought about that but I prefer to race with magnets - especially as I usually race with my young nephews and I don't want to make it too difficult for them.

Also, I have 30+ cars, so changing the tyres on them all would be a lot of hassle. Admittedly I have never bothered to buff the rear tyres with sandpaper and that will be the thing I do next with all my cars.

When one is spending £35 or more on a Scalextric car (I only ever buy high detail, never super-resistant), I would expect there to be a lot more consistency with the magnets.

The Bugatti Veyron and the McLaren MPC4-12 are truly shocking right out of the box, and it doesn't help that the magnets specified in the service sheets for those cars are no longer available
 

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Discussion Starter · #8 ·
QUOTE (RikoRocket @ 23 Apr 2012, 15:48) <{POST_SNAPBACK}>Don't mess around just get a pack of magnets. Yes you can stick other magnets on top to increase the strength. But really stick them as the magnetic force may not be sufficient to hold them together in a crash

Right...so, when stacking magnets, should I do this with magnets that are slightly smaller than the ones held in place by the plastic bits in the chassis?

If I put the same size (or bigger) magnet on top what would happen then?

Surely that's not a good idea due to the plastic clips of the magnet slot only being able to hold one magnet, and then the magnet on top of the stack will be lopsided, right?

And when you say 'really stick them' do you mean using glue with them? If so, what kind?



I noticed when I took the Bugatti apart the thin bar magnet had some gluey substance on it. It looked like it was put on the magnet to hold it in the slot, due to the proximity of the magnet slot to the motor. When I tried to remove the magnet it was sticking to the motor.
 

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QUOTE (mattcrackers @ 23 Apr 2012, 15:47) <{POST_SNAPBACK}>I measure the magnetic downforce on my cars using a set of scales which have had a hole cut in them and replaced with a metal plate which has been packed so that the metal plate is level with the top of the scales but does not touch the weighing platform, another slot is cut opposite for the guide. I can use the scales to measure the weights of cars and also the magnetic attraction. This isn't an exact science but it does let me know roughly how even the magnets are in the cars. I have 4 of the Peugeot 908's, the Aston Martin Lola and also the Porsche Spyder. My 2 fastest (lap times not straight out speed) Scalextric cars are 2 of the Peugeots which have a similar magnetic downforce, although one has a motor with a bit more go, the other 2 have less of a magnetic downforce thus don't stick to the track like the others. You will find that not many of the scalextric bar magnets are the same, some have a huge amount of downforce while others seem to have little if no downforce. The gap between the chassis and the rails can also give you a different effect as the magnet can be closer to the rails or further away resulting in different magnetic downforces.

Matt

It's shocking just how much variation there is...and it's not something I'd really given much thought to, until this last weekend when trying to race with the Spyder it was just horrendous. Only afterwards when I was trying to figure out why the car was handling so badly did I notice the difference in weight between it and the other 2 LMP cars - even though they have identical magnets (W8475) in them.

What I'm discovering, as I check all my cars (albeit in a far more basic and less sophisticated manner to the way you do it!) is that the magnets are either very strong or very weak and the weak ones are therefore next to useless.

Ember's comments about impacts I've no doubt is valid and may explain why my MC12 is the way it is (it has taken a few amount of bangs and crashes, to say the lease - including my nephew flying it into the garage door!) but some of these cars that have what seems like little or no magnatraction at all were brand new out of the box, un-raced cars!

So where is the QC at Scalextric if two cars, even if they are of the same model going by your comments, can have such a vastly different amount of magnatraction?
 

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QUOTE (kipper15 @ 23 Apr 2012, 18:34) <{POST_SNAPBACK}>Right...so, when stacking magnets, should I do this with magnets that are slightly smaller than the ones held in place by the plastic bits in the chassis?

If I put the same size (or bigger) magnet on top what would happen then?

Surely that's not a good idea due to the plastic clips of the magnet slot only being able to hold one magnet, and then the magnet on top of the stack will be lopsided, right?

And when you say 'really stick them' do you mean using glue with them? If so, what kind?



I noticed when I took the Bugatti apart the thin bar magnet had some gluey substance on it. It looked like it was put on the magnet to hold it in the slot, due to the proximity of the magnet slot to the motor. When I tried to remove the magnet it was sticking to the motor.

Yes stack them smaller on top. You can also just stick a round one on top of the bar magnet, that works fine. Use superglue, else the first roll the magnet will end up stuck to the motor. The clips will be fine with more than one magnet, but dont try and fit two bar magnets the same size under the clips or they will no longer be clips...
 

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Nobby Berkshire
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Magnets do not lose their magnetism by taking a few bumps. I think somebody is having a giggle


You need to find out why you are losing magnetism, for this could be caused by a disruption in your time/space vortex. If you don't get Dr Who called in then you may wake up one morning finding a bunch of Cybermen playing with your Scalextric.
 

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Ummm ..... see here: .... note the Tips and Warnings
 

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The difference between magnets in these cars is nothing compared to the difference in ride height. A fraction of a mm makes a huge difference in the amount of force excerted by the magnet on the floor of the car. You lower the height of poor one by trueing a bit off the tyres.
Me, I pull all the magnets out but of course this will lessen the play value for kids.
 

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Greg..where did you find that!!

Nothing to do with magnatraction/downforce on slot cars, but a lot of motor magnets on vintage slot cars naturally lose their "magnetism" over the years, causing the motor to run hot & slow.
Cheers,
Kev.
 

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A wery good story! And also a good reason to race without magnets! ;-) More fair and relevant!

(I use a very small scale thing to measure the power of the magnet. But newer race with them ;-)
 

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Howay Kev,
There are strange forces afoot .......... in my ever so humble opinion, concrete slabs are seriously under valued in slot racing
 

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I`m Sunderland so it`s "Haway" Greg! The daft Geordies say "Howay"....

Perfectly true about motor magnets. You buy some pre 1968 Jouef cars & I promise you that approx 40% of the motor magnets would have weakened over the years....it`s THE major weakness of Jouef....easily remedied by getting the motor zapped or replacement neodid magnets are available from France.
I`ve also seen it happen on a few of the old Triang RX motors.
Cheers,
Kev.
 

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QUOTE (Screwneck @ 24 Apr 2012, 07:23) <{POST_SNAPBACK}>Magnets do not lose their magnetism by taking a few bumps. I think somebody is having a giggle


Sometimes I feel like I was the only one paying attention in Physics class at school.

When I said 'impact shock' I didn't exactly mean impact from the cars, more a case of dropping the magnet. I could probably explain why it happens after another cup of coffee.
 

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QUOTE (Screwneck @ 23 Apr 2012, 22:23) <{POST_SNAPBACK}>Magnets do not lose their magnetism by taking a few bumps.
Don't you ever tire of talking nonsense, Screwneck? I so wish you would.

I'm presuming you don't have children, because if you did you'd undoubtedly have a stack of fridge magnets that have lost their magnetism having been dropped on the floor numerous times.
 

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Keep taking the tablets, maybe upping the dose will help ......
 
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