Search found 234 matches

by ngyoung
Wed Oct 01, 2014 7:14 pm
Forum: Car & Semi-Truck Photos
Topic: 2014 Hiawatha District Runner up and start of next year's ca
Replies: 8
Views: 8789

2014 Hiawatha District Runner up and start of next year's ca

Here is my scouts first derby car for tiger cubs. He found a hotwheels car he wanted to mimic for a profile and i helped him get a simple shape. This was before I had a good grasp of canting wheels and tungsten cubes. I did know enough to polish axles, make it a 3 wheeler, and by the time he was don...
by ngyoung
Mon Sep 29, 2014 7:39 pm
Forum: Car & Semi-Truck Photos
Topic: *Fenders* Nellie Faye
Replies: 88
Views: 65800

Re: *Fenders* Nellie Faye

Instead of using a half dozen clamps maybe try using two pieces if wood to sandwich the pieces you're gluing like a vice and you can clamp down more without denting the fenders.
by ngyoung
Mon Sep 29, 2014 7:10 pm
Forum: Car & Semi-Truck Construction
Topic: Front nose of car, shape, aero, thin to win ?
Replies: 53
Views: 40924

Re: Front nose of car, shape, aero, thin to win ?

Just came across this DIY wind tunnel setup. You can't set the MPH but you can find the drag force to compare your own cars.
http://pinewood-derby.blogspot.com/2013 ... n.html?m=1
by ngyoung
Thu Sep 25, 2014 1:54 pm
Forum: Car & Semi-Truck Construction
Topic: Front nose of car, shape, aero, thin to win ?
Replies: 53
Views: 40924

Re: Front nose of car, shape, aero, thin to win ?

sporty wrote:The problem with the diagrams. Is that that air flow is correlated to being in the air.

The flow is a bit different when dealing with a bottom surface. Still nice to look at and appreciate you sharing.

A lot of automobiles incorporate the Kamm tail in their design.
by ngyoung
Thu Sep 25, 2014 11:16 am
Forum: Car & Semi-Truck Construction
Topic: Alignment Tool Comparisons
Replies: 50
Views: 86049

Re: Alignment Tool Comparisons

ProBody Tool: + Eliminates the "nonparallel sides" issue. + Hole trueness much less dependent on "good drilling technique." + Requires NO drill press. - Single application tool, but priced so that the single app is much less of an issue. - Subject to much more "wear degrada...
by ngyoung
Thu Sep 25, 2014 10:40 am
Forum: Car & Semi-Truck Construction
Topic: Front nose of car, shape, aero, thin to win ?
Replies: 53
Views: 40924

Re: Front nose of car, shape, aero, thin to win ?

That said, check out this video for the NPWDL's August "Street Stock Pro" race. The winner, Lightningboy's X3, uses a 'side-fender' design... The video is almost 18 minutes. Can you reference a frame number / time which clearly shows the design being described? You can skip to the end whe...
by ngyoung
Wed Sep 24, 2014 10:22 pm
Forum: Car & Semi-Truck Construction
Topic: Front nose of car, shape, aero, thin to win ?
Replies: 53
Views: 40924

Re: Front nose of car, shape, aero, thin to win ?

So from your tests the back fenders have little impact. All of the top pro builders use 4 fender nowadays. You can find some early races with cars that only use two but eventually as they gained more experience using them all 4 were used. The full side fenders like the "Nellie Fey" you pic...
by ngyoung
Wed Sep 24, 2014 8:56 pm
Forum: Car & Semi-Truck Construction
Topic: Front nose of car, shape, aero, thin to win ?
Replies: 53
Views: 40924

Re: Front nose of car, shape, aero, thin to win ?

So in your wind tunnel testing you didn't see any drag on the back side where the body gets thick again for the weights? With the uniform thickness there is only one leading edge at the nose. I do suspect that your body style looks like it may lend itself to be less effected by dirty air when racing...
by ngyoung
Wed Sep 10, 2014 11:21 am
Forum: Car & Semi-Truck Construction
Topic: Any success with "composite filled" axle bores?
Replies: 20
Views: 19241

Re: Any success with "composite filled" axle bores?

I read on another site about someone using delrin or teflon rod, similar I think to Royal Rangers using the wood dowel. Insert the rod into the body and drill axle holes into the rod ends. This then also doubles as a slide glide surface. For the front axle it is also drilled canted but is movable en...