# Slot Car Motor Heads



## Mike Clark (Apr 28, 2007)

Hi guys,
I race 1/18 scale R/C cars and we use the PARMA 502 motors, green end bell, no timing adjustment. Looking to Blue print about 10 of these motors but had a few questions.

(1) These motors have timing built into the com, is there any way to retard the timing?

(2) On 4 AA batterys, these motors operate at 4.8VDC max so how can I get more power from the motors? We race on a oval and I want more pop than top end RPM.

(3) We use the Gold Dust & Big Foot 2 brushes are these the best brushes to use? Springs are the stock issue that comes on the motor.

(4) Brush springs, Other than changing the current draw, what other changes should I expect if a brush change from a soft to a medium or hard brush spring?

How about a little help.


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## wnovess99 (Mar 1, 2006)

*parma*

Why don't you go to a 7.2 NimH pack? Or are you limited to what batteries you have to use? 

The gold dust brushes are about the best around. 

I dunno about retarding the timing, with drag cars we typically use a small amount of advance to take some torque away. You can do that by cutting the top point of the brush back a little or turning the end bell. Parma now has a super 16 D that you can turn the end bell, the can is slotted. I think it only costs 18 dollars. 

Try a set of Pro Slot red brush springs on it.

You could solder some shunt wires on it too.


Back when I had my Mini-T I wish I was into drag racing slot cars. A nice pro slot super 16 D would probably blow the doors off that over priced Trinity stuff.


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## brownie374 (Nov 21, 2007)

Pull them apart, cut the comms ,align the brush hoods, gold dust brushes with mura red springs then break in the motors in water.the motors will then be as fast as they will ever be.remember these are machine wound arms and are not the highest quality.The only thing after that you could do is zap and match the magnets but it is a hassle getting the mags back in.You could also get the arm rebalanced after running it for awile.


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## Hornet (Dec 1, 2005)

In case nobodies specified, use Distilled Water if your breaking in your brushes in water.Tap water is a conductor,distilled water isn't:thumbsup:


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## sonsracingteam (Oct 29, 2007)

How do you break in the brushes under water? Please explain.
Thanks,
Steve


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## blubyu (May 4, 2008)

hornet, Never had a problem using tap water to break in HO motors. You have,PLEASE EXPLAIN?


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## Hornet (Dec 1, 2005)

Tap water has enough iron and minerals in it to conduct electricity.
Pure water or distilled water doesn't have those particles,so it won't conduct electricity.
Your wasting your time breaking in your HO motors under water,might work for the 1/24th guys,but not very productive in our case.
Use clean dry bearings or plastic bushings if breaking them in using water.If your car is equipped with an oilite type bushing,the water will float the oil out of the bushing,and onto the brushes/com etc.as it floats to the surface of the water.
Blubyu,what kind of cars are you breaking in under water,if your doing cars that use a sealed barrel system,ie:Tyco/Wizzard/Slottech,slot the barrels,otherwise hyd pressure will grind your brushes to nothing in a matter of minutes under water.
The brush acts like a piston in a sealed barrel


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## blubyu (May 4, 2008)

Hornet, no barrels on a BSRT G3. Thats the chassis I run under water and no oil either. I guess your using well water with a full days worth of iron & minerals. Thats the whole point of breaking in under water is not to waste the time sitting on a breakin box for a hour........


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## brownie374 (Nov 21, 2007)

Indiana tap water works fine, did it many times.


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## tjettim (Nov 29, 2005)

We used to break in 12th scale motors in Budweiser.
You do need to rezap the motor magnets after any
wet break in though.


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## Hornet (Dec 1, 2005)

And you've went "how" much faster doing this
I've used tap water lots too,but for everybody else's safety,lets give them the proper tip huh guys:woohoo:


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## blubyu (May 4, 2008)

Just save more time for the track,yes much faster and perfect segments with the extra practice and dial in time.


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## Hornet (Dec 1, 2005)

And that was how much faster.:wave:
And how much life expectancy did it add:wave:
A Wives Tale:thumbsup:


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## blubyu (May 4, 2008)

Hornet,times are only for pole position,I'm preparing for the Race:5min mains....and yes I've made those. Not looking for life expectancy,but then again I run my cars till the brush is pretty small...#1 car has 4 races (2wins,1third,1fourth & 1HOPRA main) and as for your times ran the fastest lap in practice for up coming race were I hope for #3,all on the same brushes.


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## Mike Clark (Apr 28, 2007)

wnovess99 said:


> Why don't you go to a 7.2 NimH pack? Or are you limited to what batteries you have to use?
> 
> The gold dust brushes are about the best around.
> 
> ...


At the present time our lap times are 2.80 to 2.60 seconds per lap no need to go faster. Besides we also run 125 & 250 lap races on the 4 AA batterys, so run time is not a problem. We have tried to keep our racing as cheep as possible!

Use Gold Dust, they are the best!


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## Mike Clark (Apr 28, 2007)

brownie374 said:


> Pull them apart, cut the comms ,align the brush hoods, gold dust brushes with mura red springs then break in the motors in water.the motors will then be as fast as they will ever be.remember these are machine wound arms and are not the highest quality.The only thing after that you could do is zap and match the magnets but it is a hassle getting the mags back in.You could also get the arm rebalanced after running it for awile.


Yea we have thousands of laps on these motors, they are one of the more reliable motors out there. I'll check on the Mura springs. Yep water dipping is standard to break in new brushes and have recently purchased a Brush radius tool that seems to do a good. The best dipping liquid is Freon. It cuts the brushes will polish the bushing and arm shaft with out removing a ton of materal. Since the dry cleaners quite using it, very hard to come by.


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## Mike Clark (Apr 28, 2007)

brownie374 said:


> Indiana tap water works fine, did it many times.


Yes most tap water will work fine. Most cities filter the crap out of drinking water now a days. However if you live in the country and have a Iron water supply well, stay away from it. The motors will short out.


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## Mike Clark (Apr 28, 2007)

Hornet said:


> And that was how much faster.:wave:
> And how much life expectancy did it add:wave:
> A Wives Tale:thumbsup:


Nope no wives tail. Ben water dipping R/C motors since the late 70's. The fastest way to break in motor brushes & bushings before a race.


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## Hornet (Dec 1, 2005)

R/C motors are a differant animal.
On an H/O car,i've never found any improvement.
The theory is cavitation,hate to say it,but the com slots on a h/o motor,spinning at only a couple thous rpm on a 3volt break-in box,won't provide the vacumn vortex needed to be of any benefit.
You guys been reading the 1/24th board to much.
By the way who ever came up with the cavitation theory is only a man,so just cause you've read it on a bb board somewhere,doesn't mean it's right,everybodies prone to mistakes,especially the so-called experts in this game.
Find yourself 2 as close to identical arms you can(ie:balance and ohms wise),and do a documented test,i think you'll find a water break-in isn't all it's cracked up to be on a H/O scale car,somehow i ended up in here,and i was referring to an h/o scale car,not a r/c or bigger scale slot carcar,but hey if you guys think it makes you faster,go for it:thumbsup:
I'm assuming the theory behind the freon trick is the amount of shrinkage provided by the rapid cooling cooling effect of the freon,if that's the case,try nitrogen,it's quite a bit easier to get,and should provide close to the same effect.
The best break-in i've found is a 15 min dry break-in and then run the damn car,forget the fancy snake doctor oils and stuff.2 benefits not only do you get practice,but it seats everything better and faster,axles/gears and brushes,run it the same as you would a 1:1 car,take it easy for the first couple hundred laps,then beat the hell out of it.:woohoo:
I sure as hell hope you don't take a brand new unknown car to a big race,that's only had a snake oil break-in,at least put a couple hundred laps on it to loosen up the axle holes etc.


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## blubyu (May 4, 2008)

Hornet, who said anything about the 1/24 board & cavitation? YOU! I never had a problem with tap water and yes I only use 3volt battery pack to breakin under water.I would not call it snake oil break-in. Use what works for you, Hope to race with you in a Hopra Main.........


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## Hornet (Dec 1, 2005)

LMAO,you guys are the ones who took the swipe at me first,next time think before you type:thumbsup:
Okay,now i'm curious,whats your theory on why a water break-in speeds up your break-in procedure.This i'm curious on,as to my way of thinking,the water is going to act as a lubricant and actually slow down the break-in(did a few tests on this a few yrs back myself),so explain your theory please


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## blubyu (May 4, 2008)

Your a man who came up with your theory,does that mean your right? Use what works for you. Sand your brushes if thats your theory,I'm not a so called expert.


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## Gary#8 (Dec 14, 2004)

Been using water break in on all types of DC electric motors. Not sure of the THEORY but sure is quick. I only dip motor for about 5-10 seconds at a time. Then you need to check brushes. You will be amased at how fast brush will get desired curve to fit comutator perfectly to that paticular motor comm. I also have been doing this since the 70's. Works real good when racing a handout car or motor that is brand new. Also don't need full voltage when doing this all you need is a 9 volt battery and a cup of water.  Also helps to have some type of dyno so you can see before and after results.


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## Hornet (Dec 1, 2005)

Well i'll be dammed,been around industrial DC motors all my life,and that's been since the 70's,and never seen one dipped in water to break it in.
Sorry guys but on this one we'll have to agree to disagree.:thumbsup:
Might be something to it in the bigger scales,but in HO i think your wasting your time


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## blubyu (May 4, 2008)

Hornet I guess you use nothing when drilling or cutting metal as it will slow down the process? Think outside the box DUDE!


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## Hornet (Dec 1, 2005)

That's done for cooling and lubricity dumb-ass.
I will qualify my statement a bit,you can grind a set of brushes to nothing in a matter of minutes on a Sealed Brush Barrel system,like a tyco/patriot/panther has,but that's from strictly hyd'ing the brush,and it's not a break-in procedure,it's more like smash the brush into the com so hard it has to grind itself down,but on an open brush or unsealed brush barrelled HO car,it won't speed up the process


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## blubyu (May 4, 2008)

You're Funny! Always have an answer for your theory's so it works for you. Have you tried it with a G3 yet? Or a T-jet?


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