Wheel runout quality report

[knotthed]

In preperation for Mid America we have been measuring runout of stock wheels.

A fairly large sample size >50.

Minimum .0005"
Maximum .011"

I did not log the measurements and do the statistics, but the bulk of the wheel were in the .004 to .006" runout range.

Bore sizes varied as well - did not sort those yet.

What this means is your typically going to have to remove .008 to .012" off the diameter of a wheel to true it up.

For what it is worth, I don't even look at wheel numbers as they are useless for determining quality. The only exception is at the factory, they can use the number to solve problems going on with the tooling.

[bracketracer]

Given that you are sorting wheels for Mid America, I can assume that you will need to run them with the tread edge intact. You might find it useful to check the lateral runout, the wobble, to sort your pile further.

[knotthed]

Will be machining, but people are usually interested in the quality of the wheels.

[Stan Pope]

I did not log the measurements and do the statistics, but the bulk of the wheel were in the .004 to .006" runout range.
...
What this means is your typically going to have to remove .008 to .012" off the diameter of a wheel to true it up.

I don't follow the logic of this. For the bulk of the wheels, the "high spot" was .004 to .006" above the "low spot". Turning down the "high spot" (and the rest of the circumference) should require removing from .004 to .006" so that it will match the "low spot". Where did I go wrong?

[knotthed]

Stan,

You are correct.

I was in a hurry and hungry when typing and was thinking about depth of cut being x2 off the diameter.

It cannot be x2 off the diameter if there is nothing there to cut.............

[Stan Pope]

Whew! Thought I'd finally gone totally senile!

Good report!

[chobo]

More than likely, they are running them too fast in the machine. Probably faster than the old single gated wheels being as from what i can see online is the walls are thinner. If the tool was messed up, it would always be for that cavity in that mold. More likely than not, it is all processing error.

I am assuming the wheels should be more balanced then they used to after shaving them - guessing if that is true, it is probably from the three drop 3-plate mold they are using.

[Curse You Red Baron!]

FWIW I tested for runout last year and had similar results - with about 40 wheels I found about 4 that appeared to be around .001 or less, another 4 .001 to .002, another 4 .002 to .003, and most of the rest between .003 and .007. I don't have a good setup to test bore sized either. I used a set-up that FB had posted.

[Speedster]

knotthed, your name is very familiar to me. Did you finish in the top 12 of a previous Mid America and machine your own wheels? How much did they weigh?

[murphken]

The radial runout numbers are not too bad for how long those mold numbers have been making wheels. The lateral rounout is also a concern with these aging mold numbers.

I have not checked any new wheels for several years. Shawn and I sold a bunch of our old wheels earlier this year. Those early wheels were sweet. I still remember posting results on the new wheels on Derby Talk.

We still have a stash of good wheels. Don't know what we will do with them. Shawn still has his last Scout Car in a box and I believe he put some #7s on that car. Someday, we might get the itch to get it back out and get it in a local race if they would let us run after the racing. Get the itch once and a while.
Murph