391 replies to this topic

[gotboostedvr6]

Mike,

Your taking Stu's words too literally.

If you trim the trailing edge and leave the leading edge in place you increase the median timing, the firing point stays the same.

If you trim both edges equally the median timing stays the same and the firing point gets retarded.

When the leading edge is trimmed and the trailing edge is left in place you decrease the median timing and the firing point.

[MSwiss]

gotboostedvr6, on 18 Mar 2017 - 12:30 AM, said:

 the median timing

A new term.

 

Maybe when you supplant Stuart as slot car's #1 motor authority, you can "officially" add it to the slot car car lexicon.

 

When the Hawk 6 came out , 5 or 6 years ago, I did extensive testing with cut down brushes.

 

Despite only being approx. .070" tall, brushes with both sides trimmed back, performed as well as ones with just the trailing edge trimmed.

 

IOW, the motor, with your so-called increased "median timing", was not any faster.

[Trevor Neilson]

gotboostedvr6, on 18 Mar 2017 - 12:30 AM, said:

Mike,

Your taking Stu's words too literally.

If you trim the trailing edge and leave the leading edge in place you increase the median timing, the firing point stays the same.

If you trim both edges equally the median timing stays the same and the firing point gets retarded.

When the leading edge is trimmed and the trailing edge is left in place you decrease the median timing and the firing point.

so, in theory what effect would would these 3 different cut bushes have on a motor. 

[Samiam]

Zippity, on 17 Mar 2017 - 11:40 PM, said:

"Rules are written by FEAR; and that Racers are motivated by the Fear that somebody may have something that gives others an Edge." - Rocky Russo

This may be true but is only relevant if what Racers fear is unavailable to all or only available at great cost. Here, the "Fix" is both available and of little if any cost. It also gives no "Edge' other than not melting motors and controllers. Racers shouldn't have to fear that their motor or very expensive controller may inexplicably go up in smoke.

 

These are spec sealed motors that really can't be cherry picked. Forcing racers to buy more motors looking for ones that work is counter productive and accomplishes the opposite of what rules were supposed to do.

 

"Only thing we have to fear... is fear itself" - Franklin D Roosevelt

[swodem]

I'm still unconvinced we are on the right track.

 

If the issue was purely the short, then

 

1. No PS4002FK would be a push start until the brushes had worn down

2. All the PS4002FK motors would ALL do this when the brushes were worn down

3. push start motors would be push start ALL THE TIME not just occasionally

 

But the above are simply not foolproof rules

 

There must be another variable and I think it is the comm not being true

 

I really want to hear from someone that knows what they're talking about, not people that are repeating what they have read or heard and stating it as biblical fact

[Samiam]

Isn't the cure more important than the symptoms?

[swodem]

Samiam, on 18 Mar 2017 - 04:00 AM, said:

Isn't the cure more important than the symptoms?

 

of course. Understand what is creating the symptom and you can work on prevention/cure 

[swodem]

MSwiss, on 18 Mar 2017 - 12:54 AM, said:

A new term.

 

Maybe when you supplant Stuart as slot car's #1 motor authority, you can "officially" add it to the slot car car lexicon.

 

 

 

How about you ask him then!? See if he can provide the answer. That would be helpful....

[Samiam]

I don't think the Chinese engineers are going to stay awake at night worrying about the woes of a few hundred people worldwide. What are the chances the factory will send one of their technicians to a raceway to study this issue? Less than zero. If it were the motors in Carrera or Scalextric cars letting the smoke out it would be a different story. 

 

In the case of 4002FKs in NZ racing, it seems to be more of a rule problem than a motor one.

[swodem]

Don't understand your comment
Who even suggested this ?


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[Samiam]

Who else is going to change the manufacturing process to affect a cure of this issue then? Racers can't change magnets, comms, timing, or open the motor. Their only recourse is to fix the hoods and play with brushes. Or race cars with Koford motors. Stu would like that. 

[swodem]

When Koford put out a sealed FK give me a call


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[Trevor Neilson]

Zippity, on 17 Mar 2017 - 01:26 AM, said:

Here are the New Zealand PS4002FK motor rules as they currently stand:

 

4002motor rules.JPG

OK. Am I getting confused here. Yes the rules do state what you can do with the motor, but they also state that you must use the Turbo Flex chassis and not the C43 that is being used now. From my understanding Auckland broke away from the NZSCA (and made there own rules?). ditched the TF and went with the C43. If this is the case I can't see any reason for them to follow the NZSCA rule of not trimming the motor brushes as their cars no longer conform to the NZSCA rules anyway................... NZSCA = New Zealand slot car association   

[MSwiss]

swodem, on 18 Mar 2017 - 03:29 AM, said:

I'm still unconvinced we are on the right track.
 
If the issue was purely the short, then
 
1. No PS4002FK would be a push start until the brushes had worn down
2. All the PS4002FK motors would ALL do this when the brushes were worn down
3. push start motors would be push start ALL THE TIME not just occasionally
 
But the above are simply not foolproof rules
 
There must be another variable and I think it is the comm not being true
 
I really want to hear from someone that knows what they're talking about, not people that are repeating what they have read or heard and stating it as biblical fact

Your 1,2, and 3 comments are all based on the hoods all being perfect, (fit and alignment) and the comm slotting, perfectly 120 degrees apart.

I've never measured the slotting because you need an optical comparator to do that.

It of course is a shorting issue.

No one has ever posted that cutting down their brushes didn't solve the problem.

If you truly believe it's an untrued comm, next time you come across one, take it apart and cut the comm.

It will surely get worse, with the comm being even smaller.

[swodem]

The chassis matters not
The NZSCA rules are what is up for debate
Individual club rules are not


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[swodem]

MSwiss, on 18 Mar 2017 - 06:06 AM, said:

It of course is a shorting issue.

No one has ever posted that cutting down their brushes didn't solve the problem.

It's always a shorting issue when you can apply power to an electric motor but it doesn't turn
Regardless how many poles are live

The thing is Why Won't It Turn??


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[Trevor Neilson]

swodem, on 18 Mar 2017 - 06:09 AM, said:

The chassis matters not
The NZSCA rules are what is up for debate
Individual club rules are not


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what's stopping you from trimming the brushes then.. Just use untrimmed bushes when you race under the Wellington club rules. 

[MSwiss]

I edited my post to add a but more detail.

I'm sorry you can't accept the fact that cutting the brushes always fixes it.

If you can't, obviously there is no helping you.

Rather than waste your time here, coming up with an alternative theory, why don't you appeal to your rules maker's.

Letting EVERYONE cut their brushes doesn't give any one racer an advantage.

[swodem]

Swiss
You're sounding like I'm not welcome here if I don't agree with you? Somewhat narcissistic.
I'm not interested in changing rules to put a patch on a problem, I'm interested, as I said all along, in identifying what the actual problem is.
This is my thread, if you're disinterested in it, don't join in. So far you've added Zip


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[MSwiss]

You can disagree, but when you ignore posts like 66 and 72 that corroborate what the easy cure is, it just shows you are unreasonably stubborn.

A cure is a cure, not a patch.

[swodem]

Spurred on by the warm support of my New Best Friend (Swiss), tonight I thought I'd continue on my investigation into the three Meltdown motors I have been kindly donated, like this one



Not being an Ostrich, I don't believe in sticking my head into the sand and hoping **** goes away

None of the motors I broke down had trimmed or cut brushes

The only thing I could see that they had in common was they each had bad blackening buildup from arcing on ONE com gap. I grabbed one and put it in the lathe and trued up a light cut to see what the result was.

Turns out one com segment was proud, and the first cut only took the surface off the one segment.

So I did the same to the other two. Almost identical result.



It's not definitive, it could be that
1. All 4002 motors have a proud com segment
2. Maybe the heat from the short through one segment swelled it slightly

Or possibly..

3. Push start/melting motors are what they are because they have an elliptical uneven com (what I said from the start)

Draw your own conclusions. I've stubbornly drawn mine....you don't CURE headaches with Tylenol, NBF...







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[Kim Lander]

Man this has been very interesting reading, I am now 64 years old and have been into slotcars since I was 12, never seen so many opinions.....kinda like a Baptist Deacons meeting with 8 deacons present and having 9n different opinions....race on my friends.

[MSwiss]

swodem, on 18 Mar 2017 - 08:50 AM, said:

push start/melting motors are what they are because they have an elliptical uneven com (what I said from the start)

But yet, until they self-destruct, they are fast motors on the track, just like their hypothetical, non-ellipitical counterparts.

At one of out hardbody races, one that popped in the bank,after a track call, raced by the future owner of Proslot, was turning the fastest race laps ever in this class.

So it's secret to speed, but not reliable restarting, was it's ellipitical comm? Lol

[Guillermo Suar]

swodem, on 18 Mar 2017 - 08:50 AM, said:

Spurred on by the warm support of my New Best Friend (Swiss), tonight I thought I'd continue on my investigation into the three Meltdown motors I have been kindly donated, like this one



Not being an Ostrich, I don't believe in sticking my head into the sand and hoping **** goes away

None of the motors I broke down had trimmed or cut brushes

The only thing I could see that they had in common was they each had bad blackening buildup from arcing on ONE com gap. I grabbed one and put it in the lathe and trued up a light cut to see what the result was.

Turns out one com segment was proud, and the first cut only took the surface off the one segment.

So I did the same to the other two. Almost identical result.



It's not definitive, it could be that
1. All 4002 motors have a proud com segment
2. Maybe the heat from the short through one segment swelled it slightly

Or possibly..

3. Push start/melting motors are what they are because they have an elliptical uneven com (what I said from the start)

Draw your own conclusions. I've stubbornly drawn mine....you don't CURE headaches with Tylenol, NBF...

 

 

 

This would not explain why my motor was fixed cutting the brushes. So, I also already have drawn my conclusion about what is the cause. Time for a poll?

[MSwiss]

Guillermo,
If this guys head was stuck in a vice, instead of turning the handle counter-clockwise, he would stand there until he figured out a way to shrink his head.