Updated: Pinewood Derby, phase II

"Ash78, voting early and often" (ash78) 01/07/2018 at 14:08 • Filed to: None

13

23

Today is power tool/roughcut day. Getting the stencil ready...

Hint: Final livery will be different, since it can’t appear that dad did all the work. But shape is one thing I can influence.

Hint 2: Livery will be “917, I choose you!”

Update : A couple hours later. On a whim, I cut an extra block of wood into fenders — we’re now at the max allowable width! And it looks much more accurate. Lots of fine tuning to go.

Arch Duke Maxyenko, Shit Talk Extraordinaire > Ash78, voting early and often 01/07/2018 at 14:24

0

Do you also have a top and front view to use?

Ash78, voting early and often > Arch Duke Maxyenko, Shit Talk Extraordinaire 01/07/2018 at 14:26

0

Top will be basically rectangular, but front will be tricky — hand chiseling until I go crazy with the fenders and canopy and say “ehh, good enough”

DC3 LS, will be perpetually replacing cars until the end of time > Ash78, voting early and often 01/07/2018 at 14:29

1

The key to winning in pine wood derby is to shape the front into a cone, round off the top two edges and then put lead weights in the back.

Ash78, voting early and often > DC3 LS, will be perpetually replacing cars until the end of time 01/07/2018 at 14:31

1

Lead is long gone, but tungsten and zinc do great. We did well last year (our first) with just a wedge shape, so this year we wanted more style points...and still a wedge

Arch Duke Maxyenko, Shit Talk Extraordinaire > Ash78, voting early and often 01/07/2018 at 14:32

0

Leave more stock than you think will necessary

Daily Drives a Dragon - One Last Lap > Ash78, voting early and often 01/07/2018 at 14:43

6

Remember. Camber one of the wheels and have it balance on 3

sdwarf36 > Ash78, voting early and often 01/07/2018 at 14:59

1

Lesson learned: Not the shape to use. I made a 917 for the adult class when my son was in scouts. I noticed my car was always slow on the start. Then one pass they put the car in the lane backwards-it put a car length on the field at the start! Picture the starting gate-it flips forward-top moving first. With the low nose, the car won’t move until the bottom of the stop moves far enough.

Do an experiment with a pencil as a gate-it will make sense pretty quick.

HammerheadFistpunch > Ash78, voting early and often 01/07/2018 at 15:07

1

The last time I did a pinewood derby was in college in an “open class” version for funsies with friends. Mine had rubber tires and a slot car motor.

Ash78, voting early and often > Daily Drives a Dragon - One Last Lap 01/07/2018 at 15:36

0

I just confirmed pack rules WILL allow this. Last year they wouldn’t allow it.

Sampsonite24-Earth's Least Likeliest Hero > Ash78, voting early and often 01/07/2018 at 15:59

1

What’s the purpose of this? Reduce rolling reaistance?

Ash78, voting early and often > Sampsonite24-Earth's Least Likeliest Hero 01/07/2018 at 16:19

0

Yup — it’s all about weight and rolling resistance. This cuts the latter by almost 25%.

Dr. Zoidberg - RIP Oppo > Ash78, voting early and often 01/07/2018 at 16:36

4

I won my first pinewood derby (by which I mean my dad did), and I remember being a little shit about to the other kids. Ironically, I would end up driving slow cars for the rest of my life.

Bman76 (no it doesn't need a WS6 hood) M. Arch > Ash78, voting early and often 01/07/2018 at 16:54

1

Thing which arrived yesterday:

leicester > Ash78, voting early and often 01/07/2018 at 17:01

0

Still have my first two, based roughly on Nuvolari’s Alfa P3 and the Merc Silver Arrow he beat.

Appropriately, the Alfa and Merc also placed first and second in their respective years.

leicester > Ash78, voting early and often 01/07/2018 at 17:01

0

Still have my first two, based roughly on Nuvolari’s Alfa P3 and the Merc Silver Arrow he beat.

Appropriately, the Alfa and Merc also placed first and second in their respective years.

XJDano > Ash78, voting early and often 01/07/2018 at 17:07

2

Taking shape nicely.

Ash78, voting early and often > XJDano 01/07/2018 at 17:38

0

Thanks...my version will be sans fins, but same basic shape.

gmporschenut also a fan of hondas > Ash78, voting early and often 01/07/2018 at 19:12

2

Neat. they used to do that for work to raise money for the cub scouts. I always tried to make mine like a racecar. I was even able to get it signed by sterling moss.

John Norris (AngryDrifter) > Ash78, voting early and often 01/07/2018 at 21:16

1

So you need to take the burrs off the axles - er ah nails. There are a few more tricks that I think you can find with a little internet research. I think the weight on the rear is important too. All the tracks have two parts, a slope, and then finish on a flat run. The rear weight is key for this.

If you compare a front weighted car to a rear weighted car, if they travel the same speed down the slope, the rear weighted car is going to have more time with the weight still on the slope. The front weighted car is going to stop getting a push from having the weight up the slope before the rear weighted car does. This shows in the two cars in a tie coming down the slope and then the aft CG car going into boost at the start of the flat section.

Of course it’s gotta be the most bad-ass looking car too. The gulf livery is a definite win.

Ash78, voting early and often > John Norris (AngryDrifter) 01/07/2018 at 21:27

0

Yep, all makes sense — we halfheartedly did this last year and came in second (by about .002s). This time I’m the den leader so I’m not trying to win, more trying to inspire some creativity in the other 11 boys :D

I always drill multiple axle holes for weight/balance testing, too. Sometimes adding rear weight is as simple as moving the rear axle forward a little. Buying aftermarket nails and wheels makes a huge difference. We’ll probably just re-use last year’s, which are heavily graphite lubed already.

And obviously testing the legal max width in the process!

XJDano > Ash78, voting early and often 01/08/2018 at 13:32

1

The pig was a 917, widened and longer I think, but with all the extra weight they didn’t upgrade the brakes and they wore faster than the other 917’s, and crashed.

Are you going with some poke-a-mon livery?

Not sure if my son would be into the scouts. Kind of plays by himself just fine.

XJDano > Ash78, voting early and often 01/08/2018 at 15:19

0

Also, would you do a sample test for the rest of the kids (and me as i was always interested)

Take the stock block of wood, add the weight right onto it and attach wheels. Basically if you left it straight brick shaped, how much advantage the kids get from modification.

Im sure itd be slower.

Ash78, voting early and often > XJDano 01/08/2018 at 16:49

1

Aero plays into Pinewood so little that a brick with good wheels/axles and perfectly placed weights would probably do great. It’s all about reducing rolling resistance and setting up the weight. Style points are just for fun...and to hopefully give the kids more ownership in the project.

I’ll see if I can give it a shot!