Had our race today. Now To District.

General topics of interest to racers and race coordinators alike.
Post Reply
Rpenning1970
Apprentice
Apprentice
Posts: 3
Joined: Sun Jan 15, 2012 9:44 pm
Location: Lufkin, Texas

Had our race today. Now To District.

Post by Rpenning1970 »

Well we ran our race today, my son came in second in the wolf den his average time was a 3.72, the first place car in the den was a 3.64. The quickest car in the pack was a 3.54. We ran on the same track as the district race will be on. Now the car is a long wheel base car with the rear wheels canted and 5/8 of an inch from the rear. The front wheels are 5/8 of and inch from the front with the left front raised and the right front is set up in a rail rider fashion. I also have brought the right front 1 /16 of and inch inboard. I did not testing on the track after the race and made some adjustments, i do not think the car was steering correctly. For the axles and wheels. I have polished the axles with 400 grit and the 1500 grit, i as running out of time due to work and other family things going on. I also used a file before polishing and took out the burrs. On the wheels i used the shaving tool and trued the wheels and then shaved them, but i did not shave them to the point where i had removed material on the complete surface. Do i need to shave that much as it seems like allot to me. I also used the outer hub tool. I last polish the tread surface with some 1500 grit. All of the sanding was wet sanding. I have some 4K, and 6K, and 8K sandpaper for the axles, so i should do that, will that help? Next i have a bore polishing kit from hobby lobby, i was going to do that to the bores on the wheels, what should i do on the tread surface, what grit, is 1500 high enough? The COG is an issue, his car design is heavy, it is almost the stock block with just a little removed from the front and a piece of balsa wood on top to make the shape he wanted. So far the COG i figure is about 3.5 inches. I am willing to remove some wood from the underside with my dremel but i know that i am going to be limited on that. I will try to bring the COG back but i really do not know how much that will help, his car gets out of the gates well and runs nice but i noticed other cars that would out run him in the start and others that made big moves midway to 3/4 track. Also how do i need to apply the graphite as i did not do a good job with that. Is there a super trick on that?
User avatar
FatSebastian
Pine Head Legend
Pine Head Legend
Posts: 2804
Joined: Wed Jun 17, 2009 2:49 pm
Location: Boogerton, PA

Re: Had our race today. Now To District.

Post by FatSebastian »

A lot of questions! I will address one...
Rpenning1970 wrote:I will try to bring the COG back but i really do not know how much that will help, his car gets out of the gates well and runs nice but i noticed other cars that would out run him in the start and others that made big moves midway to 3/4 track.
CoM placement makes little difference out of the gate, and a big difference in the straightaway. If you can move the CoM backward, you will be glad you did. To avoid contaminating your wheels and axles with wood shavings when hollowing out wood, it is best to remove them first.
User avatar
sporty
Pine Head Legend
Pine Head Legend
Posts: 3344
Joined: Sun Feb 13, 2005 1:00 am
Location: rockfalls, Illinois

Re: Had our race today. Now To District.

Post by sporty »

Post a picture of your car and feel free to pm. I am glad to offer help to you.

There is many questions there and allot to type and reply back.

a phone call is better suited for wanting that much info. Or spend some time searching on here.


Many polish axles upto .05 micron. 2 micron is like 12,000 grit with micro mesh, regular. its a type of sand paper.

So no 1500 sand paper grit is not even close.

Bore prep and polish is imprortant also.

There is a combination of things that all have to be done very well to have a super fast car. it takes some a couple of years to get to that level. hard work and time.

The more you build and test those cars, the better you perfect your building ability.

How you apply graphite. yes many people do it wrong and they also add to much.

I think you just need to pm me, there is way to much to go over and type, but you are a little late with already having a car built and placing 2nd. with whats left that you can do.

Aside from starting over or pre paring for next year.

Sporty
rpcarpe
Master Pine Head
Master Pine Head
Posts: 736
Joined: Wed Mar 17, 2010 11:58 am
Location: Huntsville, Alabama

Re: Had our race today. Now To District.

Post by rpcarpe »

I'll address just one issue: lots of wood. Not a good thing.
We developed a new saying in the workshop this year 'less wood, more metal'.
Your car is about .2 seconds off the lead... in my pack last year it would put you in last place.

If Sporty's willing to help, take him up on it.
My wife started a new support group... Widows of the Pinewood Derby.
User avatar
sporty
Pine Head Legend
Pine Head Legend
Posts: 3344
Joined: Sun Feb 13, 2005 1:00 am
Location: rockfalls, Illinois

Re: Had our race today. Now To District.

Post by sporty »

I sent a few pm's to him. But I have not heard back.

Sporty
Post Reply