92 replies to this topic

[bluecars]

Just drink some brake fluid, Pablo.

[tonyp]

Howie,

Bob tried those cars at Nutley when he got back from Texas, and in his words they were hunks.

[Howie Ursaner]

Bob tried those cars at Nutley when he got back from Texas, and in his words they were hunks.

 

Thanks, Tony, that's why I said "probably for the better" they wouldn't let us race LOL.

[tonyp]

Too many new ideas in one car all untested except in Bob's head.

[SlotStox#53]

Were they the chassis with the low CoG pan stops or bite bars (or whatever they were called LOL).

[tonyp]

I believe these were the small axle low CoG pan stop cars.

[Martin]

"Nutley, when Bob got back from Texas", (Mid 1969).

 

Was Bob Emott the first on the pro circuit to use 3/32" axles (mid '69)? As often happens with a new race car design when you are trying more that one concept at the same time the results are not always the best, but can we say that the 3/32" axles was significant in itself and why did he not use them from that point on?

 

How long did it take for most top pros to convert to 3/32" axle. I'm trying to understand this timeline from racers that were there.

 

So we can say that most Pros were using 3/32" axles early '70, as Tony suggests. How much of an advantage was it?

 

Did anybody ever try 1/8" hardened steel tubing; that would have been a better fit for existing gears and wheels, but maybe not as strong? Now thinking the set screw would have distorted the tubing, so dumb idea. 

 

Side note in the how-to article Model Cars... Bob is using 1/8" axles so that is while still in England after the September 7t open race at Tottenham.

 

Bob was also building with split pans at that time. How long did that trend last with Bob and others? What was the thought behind this idea?

 

Tony has already answered this in another thread Pro chassis ID challenge:

 

"It was probably very late '69 or most probably early '70. It took quite awhile for gears and tires to come out for the smaller axles. Nutley had machined adaptors but they were a pain to use so most stuck with 1/8" axles at least in the rear until proper gears and tires were available."

 

I may be repeating myself in an effort to get greater understanding. 

[tonyp]

Martin,

 

Bob believed this may be his car from the Texas race they were not allowed to race in after missing tech. It was the first small axle chassis as well as Jerry Brady's who was the one to come up with the surgical tubing to use as reducers in the wheels and gears.

 

I used to have all the old slot papers on my iPad to look this stuff up but no longer have it to check dates.

[Eddie Fleming]

Love the flat wire and the pan stops. Very cool. I am not sure how strong the stops are.

 

He was using limiters to control body flex and now they run paper-thin bodies letting them bend. Things change.

[MSwiss]

Tony,

 

I'm kind of surprised they weren't able to just use regular K&S brass tubing as reducers.

[tonyp]

It fit on the axle too lose.

[Bill from NH]

I'm kind of surprised they weren't able to just use regular K&S brass tubing as reducers.

 

Some West coast guys did use K&S when they ran Cox 48 pitch spurs. The Lee Gilbert car in the Car Model multi-issue build is one example. East coast guys mainly used the Fass machined reducers.

[Martin]

Thanks for posting that chassis Tony. Do you have any theory s on why the pans seem to have been made in 2 parts? Maybe from a split pan chassis?

 

Also the drop arm hole has been filled. All part of development i guess?

 

Very advanced looking chassis for mid 69, love the flat wire too, looks a little tricky  to work with it  though?  

 

K&S 1/8" tubing with a .014" wall looks like this. .125" minus .028"=.097" minus .0937(3/32")= a little over 3 thou  loose. Like Tony said. Would have had to make from scratch on a lathe to get a closer fit which I am sure some folks did while waiting for gear and wheel manufactures to catch up?

[tonyp]

Bob built that particular chassis in the hotel room, so he may had originally planned to use a light weight drop arm and split pans up until he saw the track and that's what he had for parts.

[Martin]

Just to get a feel for the times, would you all travel as teams and end up at the same hotel  or were you all independent. Were there rivalries between manufacturers, or was it an east vs west thing?

Looking forward to that book.Ive been hearing about.

[MSwiss]

K&S 1/8" tubing with a .014" wall looks like this. .125" minus .028"=.097" minus .0937(3/32")= a little over 3 thou  loose. Like Tony said. Would have had to make from scratch on a lathe to get a closer fit which I am sure some folks did while waiting for gear and wheel manufactures to catch up?

I think you meant 3 ten thousands loose.
 
I'm not sure if the ID ever varies much, but OD certainly does, from batch, to batch.
 
My original batch of precut K&S sleeves were probably right at .125" OD.
 
I had to ream the Parma King Crowns to make them fit.
 
The next batch I got in, 2 or 3 years later, were more like .1235", thus don't require reaming.
 
Instead, I have to put a drop of crazy glue, on the end, after installation, so they stay in place, with the set screw clearance notch, correctly oriented.
 

[Martin]

Mike, I am not sure what you mean. I meant 3 thousandths  that's .003" loose on the i.d. for a 3/32" axle. Not that bad but would have to feel it first to really know if it is good enough. You might get lucky.

 

I tried to make this as clear as possible, let me know if it is not? the mathematical number is actually .0033"  that's 3  one thousandths of an inch and  3 one tenths of a one thousandth of an inch.

 

.0001"= one tenth of a one thousandths of an inch

.001"= one thousandths of an inch

.010"= ten thousandths of an inch or 1/100th of an inch

.100"=one hundred thousandths of an inch or 1/10th of an inch( one lap around your dial )

 

All materials have specs with tolerances as you know. The best way to get that perfect fit is to machine i.d and o.d in the same operation. I do this stuff for a living. Just saying.

 

Found this to confuse you, but just so you know I speak machine shop not math class.

TalkMachinist
In general conversations or math class you may hear numbers spoken one way, in a Machine Shop, you may hear the same number described differently for example:
Keep in mind for the following:
In math class everything is based on 1.0
In a Machine Shop using Inch measurements, everything is based on .001" (one thousandths of an inch)
So, how would we say the following?
0.1000
in math class = "one tenth"
in a machine shop = "one hundred thousandths
    WHY? because if everything in a machine shop is based on .001 then there are 100 - "thousandths" of an inch
.0100
in math class = "one hundredths"
in a machine shop = "Ten thousandths"  
.0010
in math class = "one thousandths"
in a machine shop = "one thousandths" or "one thou"
.0001
in math class = "one ten-thousandths"
in a machine shop = "one tenth"
     WHY? because if everything in a machine shop is based on .001 then there is 1/10th of one thousandths of an inch
.00001
in math class = "one hundred-thousandths"
in a machine shop = "Ten Millionths"

 

 

 

[MSwiss]

Mike, I am not sure what you mean. I meant 3 thousandths  that's .003" loose on the i.d. for a 3/32" axle. Not that bad but would have to feel it first to really know if it is good enough. You might get lucky.
 
I tried to make this as clear as possible, let me know if it is not?
 
.001"= one thousandth of an inch
.010"= ten thousandth of an inch or 1/100th of an inch
.100"=hundred thousandth of an inch or 1/10th of an inch
 
All materials have specs with tolerances as you know. The best way to get that perfect fit is to machine i.d and o.d in the same operation. I do this stuff for a living. Just saying.

 

.003" loose would be awful.

That would be an .096"+ ID tube.

It would be unusable on a G7 car.

You must be used to dealing with MM, because your take on U.S. measurements, and it's terms, is way off.

You're right and wrong in the same sentence.

.100" is a tenth of an inch
.010" is a hundredth of an inch
.001" is a thousandth of an inch
.0001" is a ten thousandth of an inch

1/8" K&S brass tubing, if loose on a particular 3/32" axle, is loose by .0001"s, or ten thousandth's.

Along with the other junk on my resume, for 19 years, I was general manager of Koford Engineering, out of a lack of a better term, the Ferrari of slot racing.

[MSwiss]

Martin,
You totally edited your post.

It's way different than what I quoted and responded to.

Regardless, I reread your original post, and I misunderstood it, because you were going by doing the math K&S advertises, whole I've had 1,000's of pieces of that tubing, and sold 1,000's of Parma crown gears, sleeved with it.

It doesn't have an .097" ID, or I wouldn't of been able to sell 1,000's of gears.

PS- part of your issue is not having an "s" after "thousandth", to make it plural.

[Martin]

It fit on the axle too lose.

Mike I was trying to put some numbers on what Tony had experienced. It sound like you had a much different experience. I thought the math room talk was interesting. Now I know why people that do not live in a machine shop have different terms for the same measurements. Like I said I only speak machine shop not math class. But I did learn something.

Over and out. 

 

P.S. I fixed the s plural thing.

[Pablo]

For those of you who find the reducer tube issue interesting, I'm sure you'll love this also.

See posts 172 to 184 here:
 
HERE.
 
There are many ways to do it. The best method is the one that works.

You can do math until the cows come home but until you spin it at high speed you'll never know.

[Howie Ursaner]

Not only was it the first car to have a 3/32" axle, it was the first car with a cut-down can for low CoG. That was the thing that was concerning to us. We had never tried those motors.

[Martin]

Thank you, Howie, for confirming the first use of 3/32' axles on the July '69 Texas car.
 
It makes total sense to me also that the car he raced in Tottenham September 69 and maybe all of his cars from that point on had 3/32" axles?
 
I had not noticed this until an old friend brought it to my attention. I scaled it from the 3/4" front tires and got 3/32" front axle. Please take a look and tell me what you see.

[tonyp]

Martin,

 

Once Bob and Jerry went to 3/32" axles they never went back. It took awhile for others to follow because of a lack of suitable wheels and gears.

 

I know I used 3/32" front axles with 1/8" rears for awhile until 3/32" rear hubs were available and Fass started selling his gears with built-in adapter.

[Martin]

Thanks, Tony.

"Hard to un-ring a bell" I believe is the saying. I got out of slots soon after I got my first motorcycle and my local commercial track closed. I never saw 3/32" axles, serious air control, or a lot of things to come.

But I did get a good foundation for building and problem solving. Hope you know us kids were trying to figure out what you pros were going to come up with next.

Appreciate being able to communicate today with the trend setters. Not sure a lot of younger folks today are getting that hands on experience that I am so grateful for. Great times.