# A couple short trackers I'm working on



## micyou03 (Apr 8, 2003)

These are a couple 1/43rd short trackers I am working on. I will be decaling them over the next couple of days.




























I'll be getting to some HO stuff soon.


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## scratch (May 16, 2005)

*Pretty cool so far . . .*

micyou03,

Pretty cool so far, will be looking for more as you complete them. Don't want to sound, ah, uninformed. But when posting next time, tell what they are/came from . . .

Cheers,
Jas


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## micyou03 (Apr 8, 2003)

The coupe started as a little toy model that they used to sell at the local race tracks. It had a plastic chassis and plastic wheels. The stocker is a standard run of the mill Artin car that comes with the figure 8 tracks. I got the drivers from Hot Laps Racing and the aluminum wheels on the rear of the stocker from Liberty FLHRC from the Home Racing World board.


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## WesJY (Mar 4, 2004)

Hey Mic.. they look great man!! :thumbsup:

Wes


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## micyou03 (Apr 8, 2003)

OK, so hee are some before and after shots of the coupe, starting with the chassis. The before chassis and body are not the same chassis or body, but they are identical to what I started with.




























The motor is a robot motor I bought from Goldmine Electric for $1.25. This motor is a lower prifile than the Artin motors so it lowers the center of gravity and makes the cars handle better. It is much faster, has better brakes and can handle more voltage than Artin motors. It also gives me room to add drivers to my cars. I was building this car for a race and that's why I added the super strong magnets.When I race it it will have a standard Artin magnet. I may even try just adding weight to it instead of a magnet.


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## micyou03 (Apr 8, 2003)

OK now the body. I decaled the car, but I still have to add nerfbars and bumpers.


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## Ragnar (Aug 22, 2006)

Those look like they would be fun to race. Let us see them as you make more progress on them.


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## scratch (May 16, 2005)

*Amazing transformation . . .*

*micyou03*,

Most cool . . . always fun to see another builder's imagination. 

The before and after pic on the red car is a classic, I'm archiving that one, way to go . . .

Could've guessed Artin on the one. But ... no way could have guessed the "scaled" down red car.

Cheers,
Jas


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## micyou03 (Apr 8, 2003)

Hey scratch, You do 1/32nd right? Think you can do something with one of those bodies?


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## T-jetjim (Sep 12, 2005)

Pretty impressive work scaling down that coupe. I never would have guessed that is what you started with.
Looking forward to seeing your HO work!
Jim


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## videojimmy (Jan 12, 2006)

cool stuff!


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## scratch (May 16, 2005)

*You bet . . .*



micyou03 said:


> Hey scratch, You do 1/32nd right? Think you can do something with one of those bodies?


Hi micyou03,

You bet ... 1/32 is what I mess with. Love messing with oldies, they have character - allowing me to spiff them in ways I cannot do with much more modern rides. 

Use a lot of wire and metal bits when diddling with rides. Such as grilles, side pipes, bumpers, hood ,and side moldings, drop axles, radius rods, and so forth.

Now ... need to know how to get my hands on the raw material . . .

Take care . . . 
Jas


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## micyou03 (Apr 8, 2003)

Yea, you do very nice work. I would like to see what you'd do with one of the coupes I used.

Here are some before and after shots of the stocker now. Same deal as with the coupe.


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## micyou03 (Apr 8, 2003)

And now a few more angles on the stocker.


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## micyou03 (Apr 8, 2003)

And two more.


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## scratch (May 16, 2005)

*Nice go . . .*

Hi again,

Have to remember 1/43 scale. Really like what you did to these cars.

When seeing motors, really makes me think, you are _detailing _ a very small car. 

Assume these are Artins, really like the color schemes, especially on the one with the gold. Really stands out, would be easy to spot, nicely done . . .

Nasty a** big rear wheels as well. More chassis pics would be welcome . . .

Cheers,
Jas
PS, where did you get the red car from?


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## noddaz (Aug 6, 1999)

*Micyou03... A question about the motors...*

What is the part number of the motors you swapped in?
They look like they can be useful ..
Especially at that price...
Thanks..
Scott


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## micyou03 (Apr 8, 2003)

noddaz said:


> What is the part number of the motors you swapped in?
> They look like they can be useful ..
> Especially at that price...
> Thanks..
> Scott


G9330

Here's a link.

http://www.goldmine-elec-products.com/prodinfo.asp?number=G9330


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## noddaz (Aug 6, 1999)

*Thanks...*



micyou03 said:


> G9330
> 
> Here's a link.
> 
> http://www.goldmine-elec-products.com/prodinfo.asp?number=G9330


I saw those.
But they are only rated to 6 volts...
But if they work..
They work..
Thanks again..
Scott


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## scratch (May 16, 2005)

*6-volts*

You'd be surprised how many volts a 3 or 6 volt rated motor [arm] can handle.

Especially if run on smaller home tracks.

Biggest bane in cheapie motors is sometimes the brushes. Always check them, if copper, make them into carbon.

Cheers,
Jas


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## micyou03 (Apr 8, 2003)

We run them regularly at 16 volts with no problems. One guy has an oval track with 24 foot straights. He occasionally burns one out, but on my track with the 11 foot straights 16 volts is no problem at all.


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## scratch (May 16, 2005)

*Thanks -- PMDC motors*

Thanks . . . *micyou03 * appreciate the PM and so forth . . .
- - - -
Caveat, don't attack or "flame" the following stuff. Granted, it is simiplified, but may help some newer types get their hands around back-EMF developed by DC motors and what happens when it falls off. So, for the Electrical Engineers out there, keep your pants on and relax. This is just an exercise . . .
- - - -
Most probably know this about PMDC motors

* They "draw" amps they need, akin to torque.
* Volts are sort of "pushed" through them, the horsepower side, so-to-speak.

Note: PMDC torque is greatest at start up, one reason some slot types run their motors at higher RPMs taking advantage of the horsepower side. 

Since, after start up "0", torque has been exercised for the most part, PMDC motors become more like _horsepower _ units. The higher RPMs they spin, the more horsepower and response one gets from them. Manufactures build PMDC motors to deliver best performance at rather high RPM thresholds. Hence, it is prudent to take advantage of what and how PMDC motors are made.

* Since volts push through an armature in the motor, certain overage amount of it sort of passes through to an extent. A P [power] loss, but since most slot cars are way over powered in the first place, not noticeable.
* At rest, stiction & friction cause most distress for motors, since motors have to break these to get going. Stiction is electrical resistance, friction is of course, gearing, motor, bushings, wheels/tires, crab? alignment, twisted flag, sloppy/floppy braids, and so forth. Max torque comes just coming from rest.
* DC motors are designed to run best at higher speeds. Some tune them for home tracks at 5:1, 4.5:1. Keeping them at high rev a good bit of the time. So "motor" reaction time is instantaneous.

There are plenty of online sources for how DC stuff works. One thing all slot types should understand about DC motors, is back-EMF, _E_, understand this concept, and will rarely ruin motors. And will win more races.

P = _E _ [V-_E_] / R … P is power, _E _ is back-EMF, V is Volts, R is Resistance

EMF is Electromotive Force

As said, if don’t know back-EMF, _E_, might want to get a handle on it, since understanding back-EMF, _E_, will help in making motor choices and the like for tracks, power supplies, cars, and so forth. This knowledge can make a difference in winning and coming in second. 

As many know, back-EMF, _E_, is energy developed by motor armature as it spins. Much like a DC generator in a 1950s car. PMDC motors generate slightly less voltage, _E_, than applied voltage, V. This relationship is critical to the motor running in harmony in the car, on the track, for hours and hours. Any deviation from this relationship spells trouble for the motor longevity, and perhaps a win.

The other side of the equation current or amps, terminology, which has become interchangeable these days, is and can be the real issue. Amps will used in this little missive.

If read this far, amps is where the problem can be recognized when motors become hot or even burn up is simply this.

When the motor becomes bogged down, back-EMF, _E_, decreases since the armature spin _slows _ down, as the arm slows, it of course generates less energy, back-EMF, _E_, in this instance.

The applied voltage is still the same, even though back-EMF, _E_, is less because armature speed is down  because of more resistance being applied to the motor. Could be bad gearing, too much magnet force to track, power delivery issues, any number of things.

So, something needs to compensate for the power loss. The compensation comes from _amps_. And that spells trouble for the motor.

Perhaps an example might help, since the amps side is “missing” above. 

Slot Car Heroes has a PMDC motor a SS10 DC Motor, 
operating voltage 6-*12 * volts, 
20 to *30 * ohms, 
amperage range 0.3-0.4 amps, 
RPM 16-32K,
stall torque about 90 grams or 3.17 ounces

P = _E _ [V-_E_] / R … P is power, _E _ is back-EMF, V is Volts, R is Resistance
This illustration assumes fixed *12*-volts, and R-*30 * ohms from Heroes motor above.

The variables will then be back-EMF, _E_, due to say some sort of mechanical resistance, and of course amps as they fill the void.

Assume P = _11.33_ [12-_11.33_] /30 = 0.25 amps, within SS10 range
Assume P = _11.00_ [12-_11.00_] /30 = 0.36 amps, within SS10 range
Assume P = _10.58 _ [12-_10.58_] /30 = 0.50 amps, outside SS10 range and dangerous for motor armature.

Simplified illustration, but shows as back-EMF, _E_, falls off, because armature slows down for whatever reason, amps will increase to fill the void. The whole point is to show that when this condition takes place, DC motor is vulnerable and will either stop running or burn up.

As illustrated the closer back-EMF, _E_, is to applied voltage, V, better for the motor.

A little on the commutator, too much voltage from Turbo-Charging a layout will cause harm to commutator. Excess voltage will burn away the film put down by the carbon brushes as they brush against the comm. Burnt orange is good, dark drown is bad. Once the dark brown appears, electrical pass through of voltage is hindered. Causing more arching and fire between the comm and brushes. This condition will eventually ruin the comm, rendering the motor useless.

Turbo-Charging also will cause more arching and fire between track and brushes, causing pitting in the track rails. Track pitting causes further resistance to the braids and increases arching and fire. You can feel with your finger nail tracks where someone has consistently ran cars at rather high voltages over a period of time.

This got long ... think of volts as pressure and amps as quantity and if caring for motors means anything, try to remember as the armature _slows _ because of resistance or other distress on the motor, amps will compensate to make up the difference and fry it.

Another thing, can have a 200 amps available in a circuit, won't matter. Motor may take .5 amps, maybe 2.5 amps to start off from stiction & friction. But it will only use what it will draw. A great layout is one powered by pure DC batteries, cars run cooler and with noticeable increase in performance.

Many Turbo-Charge their layouts by upping the voltage applied. A 12-volt motor can handle short bursts of voltage beyond 12 volts. Since most home layouts do not have that many instances where cars are running flat out, it really does little harm.

Hope some of this made some sense. Many will argue with the above, many will have their version. This was typed extemporaneously, off the cuff. If replies get too hot, will simply reach for edit and delete button. But thought might help some in dealing with certain motor issues.

The main point trying to be made was how amps make up for loss of motor generated back-EMF, when the motor begins to stall and applied voltage remains the same.

Cheers,
Jas


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