23 replies to this topic

[Alchemist]

My inquiry has nothing to do with rules of sanctioned racing of any sort.
 
I'm just curious, other than "convenience" of using Set Screw Wheels on the rear of our slot cars,  do you notice a difference to the threaded axle/wheels with regards to handling?
 

 
I presume the extra weight of the threaded axle/nuts would assist in keeping the rear end planted.
 
I'm interested in observations please.
 
Thank you.
 
Ernie

[Steve Deiters]

Way back when the technology shifted from threaded axles to set screw for a variety of reasons:

 

-SS ran truer

-SS easier to change out.

-SS axles were stronger.  The threaded axle was as strong as it's thinnest point which was the cut of the thread.

-SS offered more compact axle assembly

 

These come to mind off the top of my head...

 

The good thing threaded axles taught me?  That you can use opposing items on a threaded shaft and lock them together. It has served me well for years in fact I assembled something today using that old slot racing tip. LOL

[Alchemist]

Thanks for that great info Steve - it's appreciated!

 

Ernie

[Dave Crevie]

Threaded axles did tend to wobble if they weren't threaded perfectly straight. Plus, with the nuts, you had to figit too much to get the right side play. The threaded spur gears made the situation even worse. When Cox came out with their tapered axles, I started switching to those because the wheels generally ran true. Some of the set screw wheels had some runout, especially if the axle hole was reamed a bit oversize. Tightening the set screw could cock the wheel some. But soon everyone went to those, and they were cheaper than the Cox set-up. 

[Isaac S.]

I agree with Steve, it was a great explanation. 

[old & gray]

Way back when the technology shifted from threaded axles to set screw for a variety of reasons:

 

-SS axles were stronger.  The threaded axle was as strong as it's thinnest point which was the cut of the thread.

 

 

From a machining point of view:

 

A thread profile creates a stress concentration at the sharp corners weakening it even further. (Yes I know about J threads but in 1965?)

 

Cutting a thread in a hardened piece of 1/8 steel can be a stone cold bear. Hardening after cutting can result in distortion. 

 

Last lower rotating weight means faster acceleration. 

[Bill from NH]

Not all threaded hubs are threaded true either..

[MSwiss]

I presume the extra weight of the threaded axle/nuts would assist in keeping the rear end planted.

That's an interesting take, but I've never heard of one purposely making a rotating wheel heavier.

If that was the case, one could make a wheel much heavier, and gain strength in the process.

[jimht]

Brass wheels were available sometime somewhere. Anyone else remember?

 

Threaded axles bent constantly; there was no joy in the Sixties when one bent a threaded axle during a race and had to deal with changing threaded gears and nuts and wheels. It was easier to drop out and wait for the next race.   

[Bill from NH]

AJ's had their silicones on brass & aluminum hubs in the late 60's.

[MSwiss]

Yes, and that they weren't all brass confirms the added weight wasn't going to be an advantage.

[Martin]

When it comes to wheel "run out" I wondered why the Champion's collet design never really became the standard. 

 

Possible reasons are cost and they got jammed, but that is after decades of sitting.

 

But, boy are they true. That's why we use the same method on our machine shop mills.

 

I found a pic of Atlas's collet wheels and K&B had them too.

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[Phil Hackett]

RE: Brass wheels

 

They do not work for "planting the car" *. I know because some things must be tried to be proven (1970s). One try, one fail.

 

 

 

 

 

 

 

 

*unless you're trying to achieve planting the car into a wall. Then it works perfectly.

[Martin]

That's pretty obvious, heavy wheels are slower to accelerate and slower to slow down. Not good features for going fast.

 

Found another pic of collet wheels. I know its not threaded or set screw but I am interested if anybody has thoughts on this design?

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[Bill from NH]

Yes, and that they weren't all brass confirms the added weight wasn't going to be an advantage.

 

I don't know what you're talking about. The ones I saw during 1967 & 68 had all brass hubs which looked identical to their aluminum ones. I didn't run them, but more than once I had them in my hands. They were heavy & hard, nobody ran them for long. Cox & Candies worked much better.

[MSwiss]

"AJ's had their silicones on brass & aluminum hubs in the late 60's."

 

How you worded that, I assumed you meant they had a brass insert, in the threaded area.

 

I don't remember all brass hub AJ's, but I won't dispute there was such a thing.

 

Someone like Brad Blohm or Don Siegel certainly could confirm.it.

[Bill from NH]

So you don't understand "yankee." 

 

Here's a photo of the AJs brass hubs I found with Bing. Not a good one, but it's what I could find.

 

[Ramcatlarry]

Threaded axles used right hand threads on both sides.  ONE side wheel ALWAYS came off during a race - the side that did NOT have left hand threads to self tighten.    Anyone who has ever had an MG or other car with wire wheels can tell you that the nut is different on the wheels.

 

Contrary to common myth,  3/32 axles were used before 1/8" threaded axles - came in the 1957 MRRC rail racing kits with brass wheels.  Press fit or could be made free wheeling.  Brass rims are a massive flywheel compared to aluminum or magnesium.  Foam tires were also less of the flywheel effect than solid rubber or silicones.

[Steve Deiters]

So you don't understand "yankee." 

 

Here's a photo of the AJs brass hubs I found with Bing. Not a good one, but it's what I could find.

 

NH brass Hubs.jpg

Those things weighed a ton.  There was convoluted logic floating around that time that the rotating mass aided handling.  I never really bought into it, but it sounded good for wide eyed kids in the new world of commercial slot racing.  It would seem to me they would act more like a flywheel making the braking band on your controller virtually useless. Whoa Nellie!!!

[Phil Hackett]

Those things weighed a ton.  There was convoluted logic floating around that time that the rotating mass aided handling.  I never really bought into it, but it sounded good for wide eyed kids in the new world of commercial slot racing.  It would seem to me they would act more like a flywheel making the braking band on your controller virtually useless. Whoa Nellie!!!

 

Yes, to all of the above. At least no one has thought lead wheels would be a good idea. Somehow stopping at brass was good enough.

[Rotorranch]

K&B also made brass wheels. I have some NOS somewhere around here. I never saw anyone use them in the 60's.

 

Rotor

[Jairus]

I don't believe one is better than the other regarding balance or handling.
Threaded are not "drill blanks", but unless you are driving like an idiot hitting walls, don't use either threaded or 3/32", because they will both bend.
 

[mickey thumbs]

Threaded axles used right hand threads on both sides.  ONE side wheel ALWAYS came off during a race - the side that did NOT have left hand threads to self tighten.    Anyone who has ever had an MG or other car with wire wheels can tell you that the nut is different on the wheels.

 

Contrary to common myth,  3/32 axles were used before 1/8" threaded axles - came in the 1957 MRRC rail racing kits with brass wheels.  Press fit or could be made free wheeling.  Brass rims are a massive flywheel compared to aluminum or magnesium.  Foam tires were also less of the flywheel effect than solid rubber or silicones.

 

 Nothing more embarrassing to an 11 year old drag racing the older guys than to have your wheel spin off when the light turns green.   Especially after you had smoked them your first time at the track the week before.

[Ramcatlarry]

 

 Nothing more embarrassing to an 11 year old drag racing the older guys than to have your wheel spin off when the light turns green.   Especially after you had smoked them your first time at the track the week before.

THAT was when we started using set screws on our dragstrip in the early 1962 or '63......