51 replies to this topic

[Pablo]

Why is it this motor seems slow when fresh and new, then becomes faster as time goes by?

I noticed the newest models come with instructions "For best performance, recommended voltage is 12v - 13.4.volts DC DO NOT break-in motor underwater. This will shorten the motor run life! Run motor in at 5 volts for a period of 10-15 minutes."

[MSwiss]

I'm not sure why he recommends the 10-15 minute break-in deal. I'll have to ask him.

Most guys here just put them in fresh. Usually it takes about 40 laps of practice on the flat track for them to get to 97% of max. speed.

The last 3% is usually the last 10-20 laps right before they run out of brushes.

[Pablo]

Concur, it makes sense to me now. No more cheap motors for my cars anymore.

[68Caddy]

Pablo,

Nobody down at BPR talks about this motor.

Nesta

[Pappy]

I just stick mine in and run them with no break-in. I like the Falcon and TSR motors, they seem to have more torque than a Pro Slot to me.

[JerseyJohn]

But you just don't know when they will POP.

[Noose]

That's the way I have been running them. Some slow laps to get everything set and off we go.

These motors surely do have a whole different power curve as compared to the Pro Slots. What you might, and I say might, give up on the straight (not much) you can make up on the short stuff because of all the punch. Some find them a bit harder to get used to after the Pro Slot. On lower power (like Zeps which was real low), the D3 I ran pulled the PS everywhere.

[tonyp]

It may be that timing probably increases as the brushes wear. With the brushes on arms they move towards the commutator in an arc instead of staying in the same plane. I am sure Ron could comment more.

[MantaRay]

But you just don't know when they will POP.

John,

With a bright light and some magnification... you can check the brush wear. I'm sure Noose and his 7000 watt headlight can show you how.

[JerseyJohn]

LOL.

[idare2bdul]

Another factor to consider is that the bushings are getting polished as the motor wears in and the motor spins easier. Combining this with lower drag from reduced spring tension might be contributory. Even the first Falcon motors had the characteristic of speeding up before they died. You just hoped you got your eight heats in before they died on their last run.

There is far more variation in rpm between FK motors than there are between Pro Slot motors. If you test rebuilt Pro Slot motors that have been retrued and rebalanced the differences are very small. Testing at 5 volts no load most Pro Slots vary less than a thousand RPM. Most are far closer than that. The FK style motors at that voltage have turned from 15,000 to 22,800. Most are clustered in the 18,200-19,500 range. I chose the 5 volt no load test because at 7 volts some FKs got into brush bounce. I think TonyP tests his Pro Slots at 7 or 8 volts.

To make a generalization if you have a FK motor above 19,500 rpm at 5 volts you are competitive.

FK motors test higher after a race or two than they do when new. It's hard to test brush condition because on the Trinity tester a new motor with as little as 20 minutes of break-in can often register zero. The lower the number the better. I've never had a Pro Slot register a zero. Expect the Pro Slot arm to be turning in the 28,000 to 34,000 RPM range so gear accordingly. I think a lot of people bog their Pro Slots and fail to get the most out of them. Running 48 pitch gears limits your gear choices. Foamy and I tend to run 64 pich crowns. In RetroPro Foamy and I have been running 72 pitch recently in the 5 to 6:1 range with the 4002C Big Dog motors.

[TSR]

Yadda, yadda, yadda, blah, blah, blah.
Over 2 billion sold.
Add cheese if desired.

[munter]

Great motor the Falcon range.

We are able to purchase a VII and for a couple more dollars we can get the "zapped VII."
Dunno how that fits with what you guys can buy but bang for bucks they are still a great product.

[gascarnut]

It may be that timing probably increases as the brushes wear. With the brushes on arms they move towards the commutator in an arc instead of staying in the same plane. I am sure Ron could comment more.

Are the brushes still installed with the brush face curvature at 90 degrees to the comm? I have not opened a new one in a long time, but I seem to remember the F5 and the Slick 7 motor were like that.

If that's the case, then there's probably more timing change during break-in than there will be from when the brushes are fully broken-in until when they're worn out.

[Pablo]

Are the brushes still installed with the brush face curvature at 90 degrees to the comm?

Yup.

[Mark Wampler]

No one has mentioned that the FK/TSR motors have stronger magnets than PS.

[Ron Hershman]

Yes, they do (when they are brand new and at room temp) until they get hot then the P-S mags have more strength and retain their strength. Take a new TRF or F7 motor and check the gauss. It reads 1050 avg on my meter... put the FK set-up in a toaster over at 200 degrees and let it sit for about three minutes... take them out and they will read about 600 and not go back to 1050.

Take a P-S set-up... take the readings... 900 avg... put in over at 200 degrees for three minutes take them out read them, you will find they read about 750 degrees. Let them cool back to room temp and they will go back to 900.

[Ron Hershman]

We are able to purchase a VII and for a couple more dollars we can get the "zapped VII".

You better find out what type of zapper the "zapped VII" is zapped with. If it's not a zapper made for rare earth magnet material, you're wasting your hard-earned dollars on something that can't be done on a "ceramic" type zapper.

Not too many indivduals in this hobby have "rare earth" zappers in their possession.

[Ron Hershman]

Are the brushes still installed with the brush face curvature at 90 degrees to the comm? I have not opened a new one in a long time, but I seem to remember the F5 and the Slick 7 motor were like that.

If that's the case, then there's probably more timing change during break-in than there will be from when the brushes are fully broken in till when they're worn out.

Yep... still backwards engineering when it comes to the brushes in those motors being 90 degrees off.

Over time they run in and seat properly (hopefully before they quit running)... this increases the timing and gives greater and better contact surface between the brush and comm, making the motor run faster. Also as the brush wears down the brush tension gets weaker allowing the motor to rev more.

Same goes when the magnets get hot and weaker.

[Zippity]

.
Take a P-S set-up... take the readings...900 avg... put in over at 200 degrees for 3 minutes take them out read them, you will find they read about 750 degrees. Let them cool back to room temp and they will go back to 900.

Are you getting your degrees and gauss mucked up?

[Ron Hershman]

Are you getting your degrees and gauss mucked up?

Yep, I meant points.

[TSR]

Yep... still backwards engineering when it comes to the brushes in those motors being 90 degrees off.

May I suggest a chastising letter to the designer of this motor, the Mabuchi Company, which has so far produced nearly one BILLION of these engineering heresies to power the rear-view mirrors of over 500 million cars in the past 40 years? Has anyone here ever had a rear-view mirror motor fail on them?

As a slot car motor, the specification became more radical (windings, comm design, magnets, brush-holder thickness, brush material) to produce more torque and higher revs, but with more heat ,reducing life due to quicker brush wear. The FK's brush system works fine but has a limited life as the brushes are fairly short, something that may be improved sooner rather than later. This limited life versus cost is quite satisfactory in most fair-minded racers all over the nation, with over 50,000 motors sold by JK alone, and another 22,000 sold by TSR.

A simple Penlite flashlight is all what it takes to check brush wear, and it takes five minutes at most to switch a 10-dollar motor for another 10-dollar motor after a minimum of three races with practice time.

Many think that the Falcon motors are the best physical implement ever to happen to the slot car world since the Russkit 23 motor. A Falcon 7 would have cost about a buck fifty in 1966, about 1/3 of the least expensive Mabuchi motor of the period, for greatly superior performance AND life.

So please give it a rest.

[MG Brown]

The FK series motors are an enigma, and like many things coming from the mysterious East, are a source of both puzzlement and delight for we Western heathens.

[Prof. Fate]

Hi,

Come on, P... telling us that the FKs cannot be talked about because of how many they made is like saying JPvR is smarter than you because he has more money!

Some of us LIKE motors, and like working on them. I know how to hand build a better FK, and have. Not as an effort to destroy D3 or beat you, but because I like playing with the motors.

The thing that interests me is that Ron seems to still like motors. I say this because I have seen so many people kill their hobby by making it a business.

Have we reached the point where talking about the motors, not suggesting that D3 use something different, not suggesting anything except that we do use cheap motors, has become verbotten?

Remember when the motors were blowing and folks trusted that I could autopsy them and report on what was wrong? It really is OK for some of us to find the motors interesting.

Fate

[Ron Hershman]

Many think that the Falcon motors are the best physical implement ever to happen to the slot car world since the Russkit 23 motor. A Falcon 7 would have cost about a buck fifty in 1966, about 1/3rd of the least expensive Mabuchi motor of the period, for greatly superior performance AND life.

So please give it a rest.

Parma 16D... as close to a Russkit 23 as you can get today and in the past 20 years or so with greater improvements over the 23. The Parma 16D would have also cost buck fifty in '66'with better life and performance than a 23 and the FK motor.

No need to write Mabuchi... their current FK motors have the brushes in the proper brush radius to comm placement.

Maybe a letter to your FK factory in China is in order? I have their name and address here... I can send a letter later today.