Need help! - need ideas

[Samsill]

Hello. So long story short, for the last 18 years, my 5 best friends and I (all Eagle Scouts) have a reunion to hang out, catch up, etc. In addition, we compete for huge trophy. As you might imagine, the competition gets really intense and after 18 years we have a lot of stats and records to harass each other about. The previous year's loser picks the new year's event.

This year, the event is Pinewood Derby. We've only 3 three weeks to build a car.

We're not allowed to alter the original wheels (we are allowed polish the axles which I'm planing to do.). I'm pretty handy, but with the time constraints and rules I'm trying to figure out what some of the best options are.

1) Is a wedge design best? Or a flat (Hersey bar) design better?

2) I'm leaning toward using one of those tungsten canopy's one top for weight - any thoughts?

3) If I do go with the tungsten canopy, where's the best place to place it?

4) If I don't use the canopy, should I use tungsten cubes? I've read placing two rows of cubes in front and behind the real axle is best. thoughts?

Any help would be greatly appreciated - Thanks!

 

[EvilJester]

Just my thoughts.....
I guess it would depend on how much of an advantage you think you may need to beat your friends. ( how much do you think they know about speed techniques etc ) What are the rest of your rules? Can you run 3 wheels touching?
I would go thin (1/4") and taper the front to a point.
If your able to cut out the bottom of the car for weight pockets, then definitely cubes.
If you are allowed to polish your axles, then I would imagine you can polish the wheel bore too.
If your using graphite, I would burnish the bore as well.
I would list your rules and I'm sure you will get all your answers from the pros.

Pretty cool you guys still keep in touch.

 

[Mojo Racing]

1. Go flat (1/4 is what most of the league racers do). Come to a point about 1/32 thick in front
2. Stay away from canopy
3. Stay away from canopy
4. Get 1/4" tungsten cubes, two rows behind axle, and two rows in front. Balance point (COG - Center of gravity) should be about 5/8-7/8 in front of rear axle.

Good luck !

 

[TWarwick07]

Damn canopy, got beat by an I-Beam with a canopy last week. Go thin and flat with tungsten cubes.

 

[Samsill]

Just my thoughts.....
I guess it would depend on how much of an advantage you think you may need to beat your friends. ( how much do you think they know about speed techniques etc ) What are the rest of your rules? Can you run 3 wheels touching?
I would go thin (1/4") and taper the front to a point.
If your able to cut out the bottom of the car for weight pockets, then definitely cubes.
If you are allowed to polish your axles, then I would imagine you can polish the wheel bore too.
If your using graphite, I would burnish the bore as well.
I would list your rules and I'm sure you will get all your answers from the pros.

Pretty cool you guys still keep in touch.

Thanks - yeah, it's been a lot of fun. Our rules pretty basic. We are following the rules in the box and the host has said that all 4 wheels have to touch. We're not allowed to alter the wheels - polishing the axles isn't specifically prohibited which is why I say it's allowed. (I only know about that from doing a little reading on the internet.)

What does "burnish the bore" mean? (It's been 34 years since I opened a pinewood derby box.

 

[Samsill]

1. Go flat (1/4 is what most of the league racers do). Come to a point about 1/32 thick in front
2. Stay away from canopy
3. Stay away from canopy
4. Get 1/4" tungsten cubes, two rows behind axle, and two rows in front. Balance point (COG - Center of gravity) should be about 5/8-7/8 in front of rear axle.

Good luck !

Soo... I'm hearing you say that the canopy might not be my best option. When you say come to a point, do you mean a point like this? \/ or do you mean tapper the down the front like a razor edge? Did that make sense?

Also, once you attach the cubes, do you place an additional thin layer or something over the whole or do you leave them exposed?

 

[Samsill]

Something like this?

http://www.pinewoodpro.com/p/062522.html
(I'm not looking to purchase a car, just curious if this is what y'all are talking about)

So here's another question. I was just poking around the forum where people are posting pictures. Someone posted a picture of a flat car, but it has wood pieces in front of each wheel (fenders?). It seems like this would prevent air from hitting the wheels but it seems like the overwhelming majority of cars don't do this. Am I right?

 

[EvilJester]

Heres a short thread on wheel burnishing that should get you started.

http://www.pinewoodderbyonline.com/threads/need-help-wheel-burnishing-and-axle-prep.5319/

Yes, similar design to the car you posted the link to.

For the league racers, fenders are only allowed in certain race classes , that is why you only see them on certain cars. Fenders do give you a speed advantage for the exact reason you thought.

You can use tape or duct work metal tape to cover up the bottom of your car. I use the metal tape. You can pick it up pretty cheap at your local hardware store.

 

[Samsill]

Heres a short thread on wheel burnishing that should get you started.

http://www.pinewoodderbyonline.com/threads/need-help-wheel-burnishing-and-axle-prep.5319/

Yes, similar design to the car you posted the link to.

For the league racers, fenders are only allowed in certain race classes , that is why you only see them on certain cars. Fenders do give you a speed advantage for the exact reason you thought.

You can use tape or duct work metal tape to cover up the bottom of your car. I use the metal tape. You can pick it up pretty cheap at your local hardware store.

This is great - thanks! So... if fenders haven't been excluded or even mentioned in our rules I would interpret that to mean we could use them. If I have the time, is it worth exploring going with fenders? Is that time really that much?

Of course all this to say there's no telling how crazy this race could be. Unlike normal Derby's, we won't be racing in heats with all the cars. Instead there's a pretty detailed double elimination bracket - so 2 cars race head to head each time. I know my friends are all thinking about this kind of thing, but in reality I'd say only 4 of the 6 are going to serious put time into their cars. So... if I burnish the wheels, polish the axles, and go with the design and weight you guys have suggested I think my car will be pretty competitive. But I'm not leaving anything to chance.

I mean, one year the event was checkers - and holy hell, that was the most intense and hotly debated checkers tournament on the planet. We've actually got our own "handbook" with all of our rules for the reunion and the events, etc. (before you ask, yes, several of us are attorneys)

 

[bracketracer]

If you have to race with four touching, read up on here about their unique alignment and you should have no problem with speed.

 

[EvilJester]

So... if fenders haven't been excluded or even mentioned in our rules I would interpret that to mean we could use them.

That is pretty much the untold truth

 

[Samsill]

That is pretty much the untold truth

So after looking at he rules again, it says "Any details added must be within width, length, and weight limits" I believe this would cover fenders on the side.

 

[EvilJester]

If your rule states "width shall not exceed 2 3/4" or similar, then your good to go with the fenders

 

[Pacfanweb]

Soo... I'm hearing you say that the canopy might not be my best option. When you say come to a point, do you mean a point like this? \/ or do you mean tapper the down the front like a razor edge? Did that make sense?

Also, once you attach the cubes, do you place an additional thin layer or something over the whole or do you leave them exposed?

Nothing wrong with the canopy. Might not work at the pro level, but it does just fine at most any Scout level. Your axle/bore prep and alignment is more important, IMO, than what you use for weight. You're splitting hairs (which is what wins pro races) when you are down to worrying about whether the canopy is an effective way of weighting the car or not.

 

[Samsill]

This is good stuff - thanks everyone! I've started construction of the body and fenders - looking good. I've polished the axles and I'm going to get the pipe cleaner to do the wheels. I've almost finished getting the holes for the weights dug. So here's a few more questions.

1) Should the rows of weights be equal or should more weight be infront or behind the rear axles?

2) Any painting tips? I figure painting then put together is better than trying to paint it after I've put the car together, right?

3) After I paint it, do I just do a really light sand with some superfine sandpaper to smooth the finish?

I appreciate everyone's help. I know I'm way over thinking a lot of this - and it's not like this is going to be a pro race or anything but I know my friends and I can't take the competition lightly.

 

[Crash Enburn]

There is a "Paint? Who needs paint?!" contingent here, that would point you to Sharpies. I like paint. I really, really like lacquer paint. It dries very quickly and gives a good shine. Look for spray paints that say "recoat any time". Avoid, as in run away!, paints that say recoat "within 30 minutes or after 48 hours."

The body filler primer at your automotive store is great for covering up wood grains. The other paints they sell there are typically the lacquers, and in metallics, so you can come up with a great paint job.

We typically cut the pockets on either side of the rear axles so there is 1/8" of body left on the sides, and the rear axle beam is 1/4". Two rows of six 1/4" cubes behind the rear axle, and then two more rows of six in front of the rear axle bring the cars pretty close to full weight. You're fine if you don't make it to those dimensions. Two rows of 5 behind should still result in a fast car.

Real cotton pipe cleaners, not the fun stuff from Wal*mart. Available at smoke shops.

Have fun with all this!