# magna vs non



## leonus (Dec 17, 2013)

yesterday I received two old beat up cars I got off eBay for about $8 a piece. They were in very poor condition, barely running, but I have found that half the fun for me is working on them and bringing them back to life.

one was my first afx non mag chassis. It has a green armature. After refurbishing it runs nice and smooth, but is still quite slow compared to all my other cars, and doesn't have much in the way of throttle response. Is it normal for a non mag chassis to be slower than the mags?? The brushes were in kinda bad shape, is this the cause of the lack of performance? Also, if I replace the brushes, I know they need to be the ones with the little wedge slot in one end, but to they have to be beveled on the contact end, or can they be flat? Both types are available, and it has the ones with beveled ends now.

also what's the deal with the "mean green" armature? Is it supposed to be higher performance than the one with red tips?

Thanks for the info&#55357;&#56841;&#55357;&#56985;


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## Ralphthe3rd (Feb 24, 2011)

*Mean Greens Sing !*

Leonus, your A/FX Mean Green is a 6ohm arm, and was alot faster than a Magna Traction with it's 15ohm arm. EXCEPT- the MT has much stronger magnets, so they should be close in speed- IF the A/FX isn't spinning it's tires due to lack of Magna Traction. Also, the old brushes are an issue, and those silver notched brushes should go, in favor of something like Wizzard E81 or Slottech Brushes. And if you can, throw in some DASH magnets and good silicones, and the older A/FX may whomp the newer MT's if the Mean Green is not worn out.



leonus said:


> yesterday I received two old beat up cars I got off eBay for about $8 a piece. They were in very poor condition, barely running, but I have found that half the fun for me is working on them and bringing them back to life.
> 
> one was my first afx non mag chassis. It has a green armature. After refurbishing it runs nice and smooth, but is still quite slow compared to all my other cars, and doesn't have much in the way of throttle response. Is it normal for a non mag chassis to be slower than the mags?? The brushes were in kinda bad shape, is this the cause of the lack of performance? Also, if I replace the brushes, I know they need to be the ones with the little wedge slot in one end, but to they have to be beveled on the contact end, or can they be flat? Both types are available, and it has the ones with beveled ends now.
> 
> ...


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## vickers83 (Mar 8, 2010)

Leonus, You may want to check that the chassis has the correct magnets. If there are stock tjet magnets in it, The chassis will be slow. If the beveled brushes are silver, they will be fine...JMHO....GK :wave:


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## Ralphthe3rd (Feb 24, 2011)

BTW- all things being up to snuff, in a 21' Dragrace, the AFX MT will always get the Hole-shot, but *usually, the Mean Green equipped Non MT A/FX will usually run him down in the top end.
PS, unlike Vickers83 suggestion on the OEM Silver beveled brushes, I still suggest pitching them, as they tear up the Comm on the Arm pretty bad for one thing. Actually, you can gauge how much usage the non MT A/FX had, but the deepness of the Groove worn into the comm by those dam abrasive silver brushes.


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## vickers83 (Mar 8, 2010)

Ralphthe3rd said:


> BTW- all things being up to snuff, in a 21' Dragrace, the AFX MT will always get the Hole-shot, but *usually, the Mean Green equipped Non MT A/FX will usually run him down in the top end.
> PS, unlike Vickers83 suggestion on the OEM Silver beveled brushes, I still suggest pitching them, as they tear up the Comm on the Arm pretty bad for one thing. Actually, you can gauge how much usage the non MT A/FX had, but the deepness of the Groove worn into the comm by those dam abrasive silver brushes.


If you have the proper angle & tension on the beveled brushes R3 they are outstanding performers, they don`t spin & they don`t gouge the arm. I`ve got about 5-7 AFX chassis equipped that way & they fly. I`m trying to help the guy use what he has on hand... :thumbsup:


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## leonus (Dec 17, 2013)

Thank you gentlemen, I knew I could count on you for a answers. The old motor brushes are not silver, they are black. They started out like charcoal, and looked like pencil lead after my attempts to clean and resurface them. The armature does not seem damaged or grooved on the contact surface. The magnets did look odd also, since instead of the normal red and white, these were red and blue on their bottom surfaces...

This car revs very low, which seems uncharacteristic of what has been described. I should add I suppose that both of these cars chassis seemed to almost be assemblages of non standard parts.

It might be interesting to note that the armature on the chassis of the second car, the usual red tipped type seems to be "potted" in a clear resin. The coils of wire are coated in a clear material. This chassis is a mag type, but with a curious metal piece under the front axle I assume is a weight of some sort, and a steel guide pin. After rebuilding, this one absolutely screams in the rpm department, but is difficult to drive, almost too fast, and not at all smooth on throttle response. I think that with new shoes instead of my solder and wire repaired old ones, it may smooth out. It has a tendency to fishtail like crazy as well.


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## old blue (May 4, 2007)

For entertainment sake, swap the top plates and arms on these two cars. You may see better performance out of the mean green arm. 

Old Blue


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## Bubba 123 (Sep 10, 2010)

It might be interesting to note that the armature on the chassis of the second car, the usual red tipped type seems to be "potted" in a clear resin. The coils of wire are coated in a clear material. 

the clear coating is insulation & "Potted" might mean over-heated @ sometime/place......

After rebuilding, this one absolutely screams in the rpm department, but is difficult to drive, almost too fast, and not at all smooth on throttle response. I think that with new shoes instead of my solder and wire repaired old ones, it may smooth out. It has a tendency to fishtail like crazy as well.[/QUOTE]

hi ;-)
try using a better control (Parma Economy about $25 MSRP..usually Less..)
also, cut back the voltage on the transformer (assuming u are using 18V - 22V
down 2 about 12V - 15V...)

Bubba 123 :wave:


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## Bill Hall (Jan 6, 2007)

old blue said:


> For entertainment sake, swap the top plates and arms on these two cars. You may see better performance out of the mean green arm.
> 
> Old Blue


OB is right! Do the swap and see.

If your going to stick with it, get an ohm meter and learn to test your armatures correctly. 

A cheap digital is more than adequate. :thumbsup:


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## ParkRNDL (Mar 20, 2002)

leonus said:


> (snip)
> 
> This chassis is a mag type, but with a curious metal piece under the front axle I assume is a weight of some sort, and a steel guide pin.


SCORE! That weight is from a Super Traction car. Check this thread for a little historical info and some pics to confirm what you have:

http://www.hobbytalk.com/bbs1/showthread.php?t=350100

Did you get these two chassis from the same seller? It's possible that the weight that is now in the Magna-Traction chassis was originally in the nonmag chassis that you have there...

--rick


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## joegri (Feb 13, 2008)

leon if you go to the tuning threads you,ll find the truth. its called fray tuning.read that, there you will learn all the triks to making a great running car be it tjet or afx or magnatraction.there are so many things to know but you will learn them in time. but keep playin you wont be disappointed!:thumbsup:


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## leonus (Dec 17, 2013)

Thanks park, that thread was informative. Sorry I can't post pics, but I do this on my phone which doesn't like to do that. 

It would seem to me now that the two cars have their parts mixed together. Both bodies (an orange McLaren and a black shadow with a gold wing) appear in folks pics of super traction originals, but the chassis with the weight installed is a mag...which is incorrect.

Did any of the super traction cars come with green arms? 

Is the correct orientation of the weight above or below the front axle? Mine is below, and drags on the axle...

What is the best way to remove and install wheels, especially fronts?

Thanks for all the answers, and happy racing!


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## Ralphthe3rd (Feb 24, 2011)

YES- the Super Tractions were ONLY the Original A/FX non MT chassis, and I think they ALL came with the Mean Green Arms, as for the 20 originals I own, all have Mean Greens, but I could be wrong.
Your weight is in wrong, it shouldn't touch the axle. Note the shape of the front of the chassis and the shape of the weight, the sloping parts match up with one another.
To remove A/FX independent wheel axles, just pull (hard sometimes) on the wheel that had the pointy tip, and not the side that has the hub. BUT, IF your axle/wheels were swapped to a non Independent type, you may need a wheel puller.


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## leonus (Dec 17, 2013)

Thanks Ralph, I knew you'd know.


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## slotcarman12078 (Oct 3, 2008)

That epoxied arm sounds like a rewind drag arm, with epoxy to either protect the windings from unraveling and/or to balance the arm. Get that digital ohm meter!


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## leonus (Dec 17, 2013)

The chassis with the sealed armature is ridiculously high revving it also has light olive green tips, and seems to have marks on the ends of two sections, almost like its been filed.. Could this mean it was balanced? I'm learning fast, but still guessing at alot of this stuff.. I have an ohm meter in my shed... No idea how to use it to test an armature though..

After a running it for a while, the other nonmag chassis with the green arm is performing a bit better. Still not what you'd call fast, but more responsive and smoother. 

Also, today I received my latest acquisition, a Porsche 917 afx mag, with the little pivoting wing on the back. It was in mint condition except for rotten tires. All I had to do was oil it and shine the shoes. It is another surprise, as it is so ridiculously fast it is hard to even run. I sent it down the long straight on my track on the outside lane into the guardrail to see what it could do at full power, and it blew over the guardrail, flew through the air, across the room and bounced off the wall!!

Please let me know if all these questions are a pain, I just get overwhelmed trying to sort through 1000 pages of threads..:freak:


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## Boosted-Z71 (Nov 26, 2007)

You can make a very fast magna traction car with some BRST or Nacho poly mags and that mean green arm, add a 19 tooth crown gear, some sili-foam rear tires, a shoe adjustment and it will fly on a big track, a well tuned build like that will rival some in lines.

Good find on the super-traction

Boosted


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## slotcarman12078 (Oct 3, 2008)

Not a problem leonus..High revving arms (99% of the time custom wound) can be protected from slinging the arm wire due to the high RPMs. Balancing arms can be done by adding or removing epoxy, or taking a little off the lams on the ends. 

To measure the arm's Ohms, set your meter to 200 Ohms, or there-about. Touch the probes on 2 of the copper (or silver) panels under the arm at a time, and check your readings. Do this across all 3 combinations of panels. Normal T Jet arms are in the 17 to 18 OHM range. I think Mean Greens are around 5-6 Ohms. Drag arms can go as low a .2-.5 Ohms. It's all in the wire's resistance and the number of wraps.


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## leonus (Dec 17, 2013)

After a little research I may know why the one old car is so fast. The motor brushes in it are not standard. They are a copper color, and have no "button" on one end, but are plain cylinders. Are these "wizzard" brushes? If so, will these work in a non mag chassis, without springs? If so, I am getting some, even though they are kinda expensive, cause wow that car is like it has nitrous compared to the others. Its also super smooth, and operates really low on the throttle,like its getting more "juice" somehow...


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## cwbam (Feb 8, 2010)

A low ohm chassis (6 ohm) may work better with a 45ohm controller 
90- 60 ohm controller could work well with 16-18 ohm controller

Pancake chassis are delicate motors, you can have identical setups on multiple chassis
and some may run great and a few may need or never run good. Lots of great tuning ideas here. 
My recipe is Magnatraction chassis (springs and brushes more forgiving) , good magnets
(AW, poly, ect..) and Yellow Jacket armatures or green tip /green wire from AFX chassis top plate (sometimes called non mag) try +-.470 rear tires and +-.40 front
Harbor freight tools has a cheap multi gage for ohm check.
and some armature info 
http://slotmonsters.com/slot-car-thunderjet-500-pancake-motor-armatures.ashx


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## Ralphthe3rd (Feb 24, 2011)

Leonus, those brushes will Work in *all Pancake motors, and btw- A/FX Non MT and T-JETS have springs too, they are just those single leaf springs that sit under the brush.
To date, Slottech makes the fastest Comm Brushes, then maybe Wizzard E81's although the E85's are supposed to be an improvement, and finally are JB Brushes which have a higher silver content. Back in the Day, Aurora sold High Silver content Brushes as High performance items, but also included them as OEM in the Wild Ones and Tuff Ones T-Jets, as well as the domed/grooved version in the original A/FX Non MT Cars.

*PS... NOTE- the Brushes in Slim Line T-Jets are a different size, and I believe ONLY JB's makes a replacement for those brushes.


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## TeamMadMarsupial (Dec 23, 2012)

Great thread here, following along and enjoying everyones input on the Mag/Non-Mag differences and tunning tips.

These two chassis have always been my favorites. Started mostly with Magna Tractions, but when I joined up with our race club had to, among other classes, build and tune AFX Non-Mags.

Found the Non-Mags to be a handful at first, but my brother and I spent the better part of two seasons doing a complete 180 on our ideas of what would make them work. Now, they are by far my favorite chassis to work on.

I have found the addition of weight similar to the SuperII set up and the balancing of the weight to get bite and keep it slotted has made this my favorite class to tune.


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## Ralphthe3rd (Feb 24, 2011)

And Oddly, I'm also one of those guys that prefers Non MT A/FX over the MT's....although MY personal preference, comes from the fact they were the LAST Slot Cars I was buying back in the early 70's -before I put them away, and started with 1:1 cars.
But I still prefer their brush spring design, which it shares with T-Jets. And also, with the addition of Power Steering Shoes, can slide the ass end out, as well and as far as T-Jets can.


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## Grandcheapskate (Jan 5, 2006)

Long ago, I purchased AW XT gearplates (with armature) and magnets from Bud's figuring to use them to rebuild used blank Aurora AFX and MT chassis I've had for a while. Other than the gearplate/armature, magnets (Dash magnets for the AFX chassis) and springs (mine), the chassis are built using old parts out of my parts box.

A question was asked about removing the front end. Because a lot of the cars we buy are used, we cannot be sure what has been done to them over the years. They may or may not have the original fronts. AFX and MTs had a pin style axle with one wheel free spinning and the other press fit - the press fit wheel turned the whole axle. This pin axle is about .040" in diameter. Four gear chassis appear to have come with a different front end where both wheels are press fit, there is no "head" on the end of the axle, and the axle is about .047" in diameter. The larger 4-gear axle will not fit in the axle holes for a AFX or MT unless the axles holes are opened slightly. I have a few AFX/MTs which are using the larger axle; these were no doubt modified by a previous owner probably because of the axles which were available. 

The speed I got out of the five chassis I built so far (2 MTs and 3 AFX) are equal to each other and at least as fast as any of my older cars. I believe the reason to be the magnets since the armatures are in the 16 ohm range (and AW armatures are not made of the highest quality). Both the AW XT magnets and the Dash magnets are no doubt stronger than those in my older cars. In fact, they really need to be used with a 100 Ohm controller on my 20v power source or they are too twitchy. Using older magnets really slows them down - a lot.

On my originally owned cars, I always found the MT to be faster than the AFX. However, I'll bet if I gave both types of cars new magnets, they might even out. I actually have a hard time controlling AFX cars as a good one can seem overpowered when there is no magnetic downforce. 

Joe


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## leonus (Dec 17, 2013)

Wow, so much info, I am learning volumes from u guys thank you &#55357;&#56842;

when I bought those two old clunkers, I never thought they would be so unusual and lead to so much learning. 

what I thought would be a couple of cheap runners, turned out to be a rare super traction green arm car, and an mag with a balanced drag arm from somewhere, and the weight from the super traction stuck in it.(now removed, awaiting re installation in its proper chassis..)

The mag now is running well, since the incorrectly installed weight is no longer dragging on the front axle, and even keeping the front axle from sitting straight.

the old green arm st is still slow, but I suspect with new shoes and brushes it will be hauling again. 

new question... What are power steering shoes??


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## slotcarman12078 (Oct 3, 2008)

AW/JL arms differ from Aurora's arms because there are 3 lams on the AW stuff vs. 2 on Aurora's. Whether it was to make up for inferior magnetic properties of the materials AW chose to use, or if it was to "hot rod" the arms and make them snappier to run I don't know.


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## rholmesr (Oct 8, 2010)

Grandcheapskate:
To my knowledge, the early AFX non-mag's had a .039 dia front axle. Later non-mags and all mag tractions had .047 dia front axle

There might be an exception in the short wheelbase mag tractions that perhaps continued to use the .039 axle for a while longer (Baja bronco, Porsche Carrera) - not sure about that.


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## leonus (Dec 17, 2013)

Just a little update..

The super traction shadow is now completely back together with its weight in the correct place. I put on a new set of aw shoes today, and learned else where about shimming up the loose magnets, which I also did. 

She isn't crazy fast, but she's fast enough to throw herself off the track, which is fast enough for me, and she runs smooth as silk and super quiet. All in all a success, and fun to work on. Now if I can restore the cruddy old body to better condition...


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## Grandcheapskate (Jan 5, 2006)

rholmesr said:


> Grandcheapskate:
> To my knowledge, the early AFX non-mag's had a .039 dia front axle. Later non-mags and all mag tractions had .047 dia front axle
> 
> There might be an exception in the short wheelbase mag tractions that perhaps continued to use the .039 axle for a while longer (Baja bronco, Porsche Carrera) - not sure about that.


If the non-mag AFX used the larger axle, then Aurora must have modified the mold at some point. I have a group of 12 old/used blank AFX chassis and none of them will accept the larger axle. Two others are using the larger axle, but they could have been modified by a previous owner.

I also have a couple of the bodies with detached front axles (Vega and Pinto). The axle holes on the bodies are also too small to accept the larger axle.

I only have a couple opened AFX and MTs I originally bought new and never swapped out parts. All have the smaller axle. Every four gear I own has the larger axle. A number of the used AFX and MTs I have purchased use the larger axle.

I guess the bottom line is be prepared to find either one.

Thanks...Joe


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## tasman (Feb 17, 2007)

I have seen in other threads on HT that the AW X-traction magnets are stronger than the original Magna-traction mags. If you have a pair of AW magnets you might want to give that a try.

I have several old magna-tractions that I have put the mean-green arm from an AFX in and they generally are very fast. I will say that due to the lower ohm of the arm it takes more of my Parma controller to get them going than it does for an original arm or a new AW x-traction.


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## jensen b (Nov 3, 2009)

Hi leonus,

More tips on the MT, this is what I do here in the UK.

Change the rear hubs to Tomy turbo ones they are wider and there is a better selection of tires too.

Fit new brush springs if you havn't already, this will help with the loss of power in the green arm powered car.

We are racing them on 18v, makes them interesting to drive with wheel spin using silicones.


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