by "cbell04" (cbell04)
Published 01/25/2017 at 20:29
by "cbell04" (cbell04)
Published 01/25/2017 at 20:29
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STARS: 4
Son and I are building a pine wood derby car. Hoping less contact = less rolling resistance = more speed! Not 100% finished but we’re nearly there. Comes in at exactly 5 Oz. Most of the weight is as low as we could get it just in front of the rear wheels (3oz). The rest of the weight is just the body and wheels.
"Decay buys too many beaters" (decay)
01/25/2017 at 20:36, STARS: 9
From an engineer who had engineer parents that were way too competitive about this during my childhood....
Graphite powder on the wheels at the axle, you’re welcome.
"crowmolly" (crowmolly)
01/25/2017 at 20:38, STARS: 1
Apparently one of the “tricks” that people do now is axle polishing.
"cbell04" (cbell04)
01/25/2017 at 20:39, STARS: 2
oh trust. I’m locked and loaded. Axles were polished from 400 to 1000 grit sand paper using a drill as a lathe so we will be good with the wheel, axle, camber, graphite combo.
"cbell04" (cbell04)
01/25/2017 at 20:40, STARS: 2
see my reply below/above
"Highlander-Datsuns are Forever" (jamesbowland)
01/25/2017 at 20:45, STARS: 0
I built my pine wood car like an F1 car. All the down force slowed it down.
"cbell04" (cbell04)
01/25/2017 at 20:49, STARS: 0
Mine was a Porsche style whale tail car. It lost pretty bad.
"Highlander-Datsuns are Forever" (jamesbowland)
01/25/2017 at 20:52, STARS: 0
The car that won our race was a hack job and the kid dried the paint in the microwave. So it has burn marks all over it, I hated that kid that night.
"comes over to help work on your car and only drinks beer" (00cyclonefan)
01/25/2017 at 20:59, STARS: 0
My older brother was in scouts, but I never was...I think he got 2nd or something in his races. Never really thought much about me not being in scouts until many, many years later, my mom was all bagged up after a family wedding and she started bawling telling me how they didn’t let me be in scouts because they thought it took too much time with my brother.
So...yeah, my parents didn’t let me in scouts because they didn’t want to spend that much time with me.
"cbell04" (cbell04)
01/25/2017 at 21:02, STARS: 0
That pretty sad. The whole thing is pretty time consuming but honestly I’ve made some friends of the parents and the kid just enjoys the heck out of it. Also you have one of my top favorite kinja names.
"cbell04" (cbell04)
01/25/2017 at 21:02, STARS: 0
That pretty sad. The whole thing is pretty time consuming but honestly I’ve made some friends of the parents and the kid just enjoys the heck out of it. Also you have one of my top favorite kinja names.
"comes over to help work on your car and only drinks beer" (00cyclonefan)
01/25/2017 at 21:14, STARS: 0
Ehh, it probably sounded worse than it was...we spent a lot of time together as a family no matter what, it’s just that they didn’t want the hard set obligations. I was kind of vicariously in scouts, since I pretty much tagged along on all my brothers’ stuff...which kind of helped because I ‘kind of’ experienced it, but also makes me realize what I didn’t actually get to do myself.
The name: Thanks...when I was trying to think of something, I wanted something that would make people never take me too seriously...I’m a quasi-car guy, but I’m not an expert or a hard core wrencher. Figured that one would let everyone know just exactly how seriously to take any of my comments.
"TheRealBicycleBuck" (therealbicyclebuck)
01/25/2017 at 21:18, STARS: 0
Did you implement the three-wheel strategy? You know, mount one wheel high and balance it so that it rides on the other three?
My son’s first car was a triceratops. No kidding. I did the rough cutout and he sanded on it for weeks. That one won most unique. We went more conventional after that. His last one was a simple block. He got lazy and didn’t want to work on it. Blue block with a red stripe. At least he painted it. I thought it might end up as a pine wood block with four nailed-in wheels.
"Party-vi" (party-vi)
01/25/2017 at 21:36, STARS: 1
Maaaaaaaaaan my dad and I (read: Dad mostly) made some awesome pinewood cars. First car is far right - nothing special. Second car (dragster) had ridges dremeled into the wheels for less contact and less rolling resistance, and had hub caps filled with graphite powder hoping for less rolling resistance. The bomber only had three ridged wheels, under the impression that less wheels = even less rolling resistance. The last car there was our Duesenberg tribute.
"cbell04" (cbell04)
01/25/2017 at 21:37, STARS: 1
They ruled the 3 wheel deal illegal now. All wheels must touch and spin during inspection but yes one wheel is barely making contact. :)
"cbell04" (cbell04)
01/25/2017 at 21:43, STARS: 0
Nice collection! They’ve gotten a little stricter than when I was a kid. 3 wheels are banned, any modified wheels are banned betting the hub caps would dq you too.. I only did one it was a Porsche style whale tail design but it got dominated.
"tromoly" (tromoly)
01/25/2017 at 21:45, STARS: 0
Why not chuck the wheel in a drill and cut the flat part off? Less rotating weight and less contact.
"cbell04" (cbell04)
01/25/2017 at 21:57, STARS: 0
Modified wheels are forbidden
"PS9" (PS9)
01/25/2017 at 22:08, STARS: 1
YOU ARE CORRUPTING OUR YOUTH WITH EVIL CAMBEROLOGY! I’M CALLING CHILD SERVICES ON YOU!!
"cbell04" (cbell04)
01/25/2017 at 22:12, STARS: 1
Now my son will probably by a Prius and stance it for fuel economy because his daddy taught him it was more efficient. My god what have I done?!?!
"tromoly" (tromoly)
01/25/2017 at 22:19, STARS: 0
Gotcha, that’s a slight bummer.
"Party-vi" (party-vi)
01/25/2017 at 22:19, STARS: 0
That’s rough. It must be boring now.
"cbell04" (cbell04)
01/25/2017 at 22:24, STARS: 2
We shall see this sat. Sure it’ll still be a fun event for the kids. They know not of our lawless past
"thebigbossyboss" (thebigbossyboss)
01/25/2017 at 22:27, STARS: 0
Our pine derby cars rolled downhill therefore we wanted max weight. Or am I missing something?
"Rock Bottom" (rockbottom81)
01/25/2017 at 22:32, STARS: 0
I used to auger as much wood out of mine as possible and then ballast them in the rear with Mallory ( https://en.wikipedia.org/wiki/Mallory_metal ). Getting the weight back as far as possible seemed to help maintain horizontal velocity later in the track. I was never in first at the bottom of the hill, but I almost always passed the pack at the end!
Also, that graphite powder.
"cbell04" (cbell04)
01/25/2017 at 22:41, STARS: 0
5 Oz is the max.
"cbell04" (cbell04)
01/25/2017 at 22:50, STARS: 1
Ahhh tungsten. hadn’t heard it called Mallory before. I ended up using a half dollar shaped 3oz fishing weight and planted it in as low as possible just in front of the rear wheels. the tungsten weights I looked up were going for 23 bucks on amazon! straight to the tackle box I went!
"thebigbossyboss" (thebigbossyboss)
01/26/2017 at 00:25, STARS: 0
ah.
"Rock Bottom" (rockbottom81)
01/26/2017 at 09:21, STARS: 0
Yeah, Mallory was the trade name for a tungsten alloy that we use for crankshaft balancing. I still have a few chunks around here somewhere...
"bmil128" (bmil128)
01/26/2017 at 12:37, STARS: 0
I have a month to get mine done for the parents race. This is my plan
"cbell04" (cbell04)
01/26/2017 at 13:35, STARS: 0
Nice. This is my 1st year so wasn’t sure how it all worked and was already volunteering to assist with track duty so figured that’d be enough fun for one day. Good luck!
"davesaddiction @ opposite-lock.com" (davesaddiction)
01/27/2017 at 10:06, STARS: 0
My son and I made one a couple years ago that did really well (3 wheels were allowed) and then I made one similar for my daughter that year, assuming the rules were the same. Nope! My wife failed to get them to me - that had to made all kinds of modifications and it was slow as hell. Just finished hers up this year; should be much faster!
"davesaddiction @ opposite-lock.com" (davesaddiction)
01/27/2017 at 10:08, STARS: 0
Whoa.
"Stapleface" (patrickgruden)
02/06/2017 at 10:33, STARS: 0
I just happened to find this post. Did you have the derby yet? How did you do? Oddly enough, I fell down a youtube rabbit hole the other day and ended up watching this video on tips/tricks for winning at the pinewood derby.
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Seems like there’s some good stuff in here, some of which you’ve already implemented.
"Smallbear wants a modern Syclone, local Maple Leafs spammer" (smallbear94)
02/13/2017 at 08:18, STARS: 0
I could be way off here because I never did anything of this nature but...
It is a gravity-powered downhill race, no? in that case I’d think more weight/lower rolling resistance would work better than lightweight. Within reason of course.
"cbell04" (cbell04)
02/13/2017 at 08:26, STARS: 1
Exactly. Only problem is 5oz is the limit. Everyone shows up within a couple grams so it really comes down to rolling resistance.