I think all that really matters is wheel alignment and smooth axles
and wheels. The areodynamics are way down the list. Weight is, of
course, assumed to be brought right up to the limit. Measure in
grams, (141.7 if memory serves) you will likely have better resolution
on your weigh scale.

Some say the weight needs to be toward the rear.

The wheels should have been on a day or two before the competition.
(I know, hindsite is 20-20). Roll the car down a sheet of plywood,
over and over, watch to see where it goes. Bend axles accordingly.

Yes, pull them suckers off, yank the axles anyway you can. re-drill,
and re-set, if you still have time. Otherwise, push, bend, whatever.
You will see a very very slow time at the rate of turning you have
now.

if you are re-drilling anyway, drop the car a few thou. You should
drill for the axles at around .218 up from the original bottom. That
will leave you the required 3/8 inch ground clearance. Use a #44
drill.

tighten up on the 1/16 to 1/8 space you talk about. Look at toe in,
are the wheels sitting stright up and down?

Our pack runs a Dad's class. Takes some of the heat off some of the
boys. Including mine, I am sorry to say I really want him to have a
fast car. He just wants one that looks cool. So we have compromised.

The dad's class turns out some pretty fancy stuff. The rules are.....
bent. Last year I got tromped by a guy that used wheels he turned off
a CNC lathe. Tall wheels. His frame was carbon fiber screwed to a
little bit of pine. He works for a race team here in Indy. His kid
had the winning car in the boys class. My wife asked his kid, how did
your car get such a nice paint job? He said, I don't know. Later I
heard the boy say he was not allowed to touch his car.

Sour grapes? Maybe a little, I came in second place with stock
wheels. And my kid lost to his kid.


This year, we are backing off a little, I am not building a car at
all, my kid is handling all body duties on his car, I will just handle
his axles and wheels.


Okay, maybe I need help!!!! But the boys will all have fun, anyway.

-Dan V.


On 6 Mar 2004 07:40:23 -0800, (usenetdg) wrote:

I'd like to thank the many who offered great suggestions in this
thread, to which I'd originally posted a few weeks ago. The car we
made wasn't great, but we learned a few "what not to do" things for
next year.

The car is about to be weighed and impounded. Last night, I put the
wheels on. I was really disappointed.

The big problem is that the car pulls sharply to the left. In fact,
when pushed (i.e., not using gravity), it winds up going in a circle
with a 10-12 foot radius!

I had put glue in the axle slots before putting the axles in, so I
didn't want to mess things up worse by removing the axles. I tried
pushing the front wheels a bit so as to bend the front axles to
straighten the car out, and that may have helped a bit.

What is the best way to assure straight alignment next year? And any
suggested alignment fixes for this year? I don't want to tear the
axles out. Both front wheels have (guessing) 1/16 to 1/8 an inch of
space between them and the body.

The other issue is wheel spin. I read somewhere that well-turned
axles, properly polished and lubed with plenty of graphite/moly,
should cause the wheels to spin for 20-30 seconds freely. I doubt
ours spin for much more than 10 seconds. I have added PLENTY of
graphite!

Our bottom line is we had fun working together on this (with me doing
98% of the work - my son is barely 7 - but he was watching and we were
talking the whole time). But given how much research I did on doing
things right, I wish we'd attained better results.