Correct way to shape axle thread?

[ZiggyDude]

I have read a lot on the forum about polishing the axles and most of that seems to fit what I am doing. I am just using a white liquid paste after the 2000 grit instead of Brasso I guess.

But the part I am never sure about is what people are referring to as tapering the axle head.

What I have been doing is using either a sharp file end or a point of an X-Acto inside of the head to remove that mold mark or line. When done the axle head is slightly shaped like and umbrella - kinda hollowed out a bit.

Then I take the 2000 on the edge of the head to remove any possible sharp spots.

Is this correctly tapering the head?

 

[derbydentist]

Maybe show a picture so we can see exactly what it looks like when you are done

 

[davet]

Not a great pic but you can see how the underside of the head is not at a 90 degree angle to the shaft. It tapers up as you move out to the edge of the underside of the head. We use a file that has no serrated teeth on the edge. That way the edge of the file doesn't damage the shaft.

 

[derbydentist]

Looks right to me! Take with a grain of salt though

 

[ZiggyDude]

Thank you for the replies.

So, I have been doing the opposite? If my axle was a giant, the inside would be shaped like an umbrella. The axle head having metal removed where the shafts contacts the nail head.

 

[Jimmy & his 2 Kids]

Basically think of the umbrella when a big gust of wind comes and WOOSH!!! Turns it inside out. Basically an inverted cone. This way you are reducing the surface area of the underside of the head that the outer face of the wheels hub is rotating against. Less area, less friction, faster spinning wheel. Dave's pic says it all if you look close. You can also google it. I found close up pics that way. Hope that helps some.

 

[5KidsRacing]

 

[HAB]

5 Kids - Is that drawing to scale or meant for a generic graphic for explanation? It doesn't look like there is much bevel on the underside of the nail head.

 

[5KidsRacing]

to scale, you just want a small contact area between the axle head and the wheel hub....

 

[5KidsRacing]

I posted this when the TX axles came out... it shows how you want a small contact area and you want it close to the axle as possible. Further out, more lever arm, more braking action...

 

[HAB]

Thank you for the diagrams. I have been reducing the diameter of the nail head, but may be putting to much bevel on the underside of it.

 

[ZiggyDude]

My thanks to everyone on this.

Wow - I was doing it backward!

I have not been reducing the second step. So even with my hollowed out I was in the "Not As Good" side.

 

[Briggs_Power]

I posted this when the TX axles came out... it shows how you want a small contact area and you want it close to the axle as possible. Further out, more lever arm, more braking action...

Do I have to buy a photobucket account to see images that are listed on photobucket? Anyone who uses photobucket, I can't seem to look at the images. Sometimes I can open image in another tab but usually it just takes me to the person's photobucket account and I have to look through all images. Sorry for posting this here..I really wanted to see how I should be coning my axle heads. And I also would like to figure out how to put speed grooves on my axles. I already have a khouse groove setup so good on that. Thanks

 

[Jimmy & his 2 Kids]

Here's pics of my axles I prepped for our Awana GP. Wish I could rotate the thumbnail img tho. the 2 together is a before and after.
Hope this helps.
Jimmy

 

[Briggs_Power]

Here's pics of my axles I prepped for our Awana GP. Wish I could rotate the thumbnail img tho. the 2 together is a before and after.
Hope this helps.
Jimmy
View attachment 882 View attachment 883

Awesome thank you. Did you do that with a file? I've been buying cheap needle files here and there, but they akways turn out to be garbage. I need to suck it up and buy a nice set. Do you mind telling me which files you use, that is if you even used a file for that. Thanks

 

[Skywalker Racing]

I posted this when the TX axles came out... it shows how you want a small contact area and you want it close to the axle as possible. Further out, more lever arm, more braking action...

 

[Briggs_Power]

Thanks Skywalker!

 

[M Tull]

Awesome thank you. Did you do that with a file? I've been buying cheap needle files here and there, but they akways turn out to be garbage. I need to suck it up and buy a nice set. Do you mind telling me which files you use, that is if you even used a file for that. Thanks

The following link also discusses axle head modifications and options for files.

 

[Thinkin'Bout Racin]

Sky walker,

I am certainly not going to disagree with this, but I would like to understand. If the contact point is further out, I understand what you are saying about more leverage against the hub. However, isn't the amount of force (friction) that is applied out against the axle head constant? I believe that that force is a constant, so wouldn't you be distributing that same amount of force against a larger surface? So therefore would you not have less pressure per square inch?

Also, is there an advantage as far as stability with the contact point moved outward. Would this contribute to a more stabile wheel with less runout?

Again, I am just trying to wrap my simple brain around this. Any help would be appreciated.

 

[CFD Engineer]

Same amount of force further out radially, yes. But Energy = Force * distance, and while touching further out radially, this is a longer distance the friction point moves in each revolution, hence more lost energy.

Put another way, further out is a larger torque, just like having a longer breaker bar on a wrench, you are able to apply more torque with the same force. Torque also has units of energy (ft*lb).