This Pamphlet Includes

PACK 129

2018PINEWOOD DERBY

This Pamphlet Includes:

Theme Awards Categories

Pinewood Derby Build Workshop

Scout Class & Open Class Rules

The Physics & Why

Extreme Tips & Secrets

Quick Build 12 Steps

THEME AWARDS

One winner in each of these categories will win a trophy!

(Voted on by the Pack 129 Pinewood Derby committee)

MOST PATRIOTIC BEST SCOUT THEME

BEST SPORTS THEME MEANEST CAR

BEST PAINT JOB MOST CREATIVE

Pack 129 Pinewood Derby Workshop

SUPPLIES

SUPPLIES PROVIDED BY PACK 129

(1) Pack 129Modified Pinewood Derby Kit Consisting of:
(1) Pinewood derby body with axle holes already drilled
(4) Official BSA pinewood derby wheels
(4) Official BSA pinewood derby axles (including (1) DFW “steer axle” - This axle has a notch cut in the axle shaft and axle head)
(8) Different grades of wet/dry sandpaper for axle sanding
(1) Bottle of Novus 2 for wheel bore polishing
(4) Walgreen’s brand Q-Tips stems for wheel bore polishing
(2) Large fluffy cotton pipe cleaner for wheel bore cleaning
(1) Custom Drift Chart for pinewood derby car tuning
(1) This Workshop Handout

SUPPLIES PROVIDED BY SCOUT

Tools
Cordless drill or drill press
3/8” drill bit (for weight installation)
Small digital scale (Post Office has one in the lobby)
Handsaw, Coping saw, Mitre saw… something that cuts wood
Ruler or credit card (Something thin to balance the car on)
Needle nose pliers
Vise (a cordless drill will even work as your vise)
Small sized regular screwdriver
Rubber mallet (or regular hammer)
Pair of any size vise grip type pliers
Small file, nail file or emory board

Supplies
LUBRICANT!!! IMPORTANT!!! (I recommend Hob-E-Lube for graphite and Krytox for oil)
Clean cotton cloth for axle, wheel & car cleaning
Weight… Weight can be anything…. Pennies, lead, tungsten, zinc..… Round weights are easier because you can just drill a hole and put them into the body.
Cup of warm tap water
Glue (Epoxy, CA, White, etc…)
Painters Tape (Masking Tape)
Different grades of wood sandpaper for sanding wood body (Menards, Lowes, etc.)
Paint (spray can)
Shoe Box or something similar and packing materials

Pack 129 Pinewood Derby Workshop

AXLES

POLISHING THE AXLES

Supplies needed:

(4) Pinewood derby axles (including (1) DFW “steer axle” - This axle has a notch cut in the axle shaft and axle head) (supplied by Pack 129)
(8) Different grades of wet/dry sandpaper (supplied by Pack 129)
Clean cotton cloth
Cordless drill
Cup of warm tap water

Start with the (4) Official BSA pinewood derby axles (including (1) DFW “steer axle” - This axle has a notch cut in the axle shaft and axle head)

Remove crimp marks and flashing from axles
While spinning an axle in a cordless drill use a small file, nail file or emory board to remove the crimp marks on the axle shaft and the flashing at the axle head. Do this gently so you don’t remove too much of the axle shaft, just the crimp marks.

Chamfer axle head and undercut shaft to head transition
While spinning the axle in a cordless drill use a small file to angle the axle head slightly and to undercut the area where the axle shaft meets the axle head

Sand each axle with wet/dry sandpaper
Locate the (9) 1/4” strips of sandpapers provided in your Pack 129 PWD car build kit.
Lay out you strips in order from coarsest grit to the finest grit. You have 600, 800, 1000, 1200, 1500, 2000, 2500, 3000grit sand papers in your kit and they should be arranged in that order.

The (8) different grades of sandpapers are color coded as shown below:

While spinning the axle in a cordless drill dip the first, coarsest, sandpaper (600 grit) in water and evenly sand the axle shaft (where the wheel rides) with this paper for 10 seconds (one thousand one, one thousand two, and so on…) Next sand the underside of the axle head for 10 seconds. You will use this piece of sandpaper for all 4 axles so only use a section that is 1/4thlength of the sandpaper. You will move to a new section of the sandpaper with each axle.

While spinning the axle in a cordless drill take a piece of cotton cloth and clean off the axle of any sanding residue from the sandpaper you just used.
Repeat steps “c” and “d” above for each of the (8)grades of sandpapers with 3000 grit being your last.

Lastly, while the axle is spinning in a cordless drill take the clean cotton cloth and dry the axle thoroughly.
The axles are done!

Pack 129 Pinewood Derby Workshop

WHEELS

POLISHING THE WHEELS BORES

Supplies needed:

(4) Official BSA pinewood derby wheels (Supplied by Pack 129)
(4) Walgreen’s brand Q-Tips stems (supplied by Pack 129)
(2) Large fluffy cotton pipe cleaner (supplied by Pack 129)
(1) Bottle of Novus 2 Bore Polish (supplied by Pack 129)
(1) Clean cotton cloth
Cordless drill
Cup of warm tap water

Take (4) Walgreen’s brand Q-tips and cut off the ends at a 45 degree angle. Note: Only Walgreen’s brand Q-tips will work, Q-Tip brand Q-tips will have too large of a shaft. NOTE: The Q-Tips in the Pack 129 kit are already cut for you!
Chuck up one of the Walgreen’s brand Q-tip shafts into your cordless drill.
Take a wheel and squeeze a pea size ball of bore polish into the inside hub.
Hold the wheel in your left hand and the cordless drill in your right hand.
Spin the cordless drill very slowly…. This is VERY important! The drill is turning slow as you can get it to turn. Place the drill on its slowest setting and barely squeeze the trigger until it just turns.
While spinning the drill very slowly insert the Q-tip shaft into the wheel bore and slowly work the wheel up the Q-tip shaft, back down the Q-tip shaft, back up the Q-tip shaft and then back down the shaft and remove the wheel while still spinning the drill/Q-tip. NOTE: YOU PROBABLY WILL HEAR A LOT OF SQUEELING DURING THIS STEP AND THAT IS GOOD!
Take the clean cotton cloth and use it to polish the outside and inside hub with your hand. Use the polish that is left over from the bore polishing process and use a twisting motion to polish the hubs. This should take maybe 10 seconds or so each side.
Drop your wheel in the cup of warm tap water and let it soak for a minute or two.
Cut your cotton pipe cleaner in half. You are going to use one piece wet and one piece dry. NOTE: The pipe cleaners in the Pack 129 kit are already cut in half for you!
Take the wheel out of the water and clean the outside off with a clean cotton rag. Try and get all of the large clumps of polish off the wheel.
Dip one half of the pipe cleaner in the warm water and then insert it into the wheel bore. With the pipe cleaner remaining in the wheel bore, move it back and forth to remove any polish left in the bore. NOTE: BE VERY CAREFUL NOT TO SCRAPE THE INSIDE BORE WITH THE METAL WIRE IN THE CENTER OF THE PIPECLEANER. I would recommend that the adult helper insert the pipe cleaner in the wheel bore for the scout.
Repeat steps “h” though “k” a couple times to make sure all polish is cleaned out of the wheel bores.
Once again use a clean cotton rag and clean off the entire wheel.
Take the other half of the pipe cleaner, the dry clean half, and insert it into the wheel bore. With the pipe cleaner remaining in the wheel bore, move it back and forth to dry and polish the wheel bore. NOTE: BE VERY CAREFUL NOT TO SCRAPE THE INSIDE BORE WITH THE METAL WIRE IN THE CENTER OF THE PIPECLEANER. I would recommend that the adult helper insert the pipe cleaner in the wheel bore for the scout.
Blow the wheel off to remove any pipe cleaner debris, dust, lint, etc….
Repeat steps “a” through “o” for the other (3) wheels.
The wheels are done!!

Pack 129 Pinewood Derby Workshop

BODY

The pinewood derby block you received in your pinewood derby kit has pre-drilled axle holes. The rears are negative canted (drill at a downward angle) the left front is drilled straight (DFW – steer wheel) and the right front is drilled straight and is drilled higher that the left front. The bottom of the pinewood derby car body is marked “R” for REAR, “F” for FRONT and “DFW” for the steer wheel. (The other front wheel is the lifted wheel)

The pinewood derby block you received has pre-drilledaxle holes for the fastest, most stable design. The front axle hole locations are 1-1/8” from the front of the body and rear axle hole locations are 5/8”from the rear of the body. The rear wheels and the left front wheel (DFW – steer wheel) are drilled 1/8” up from the bottom of the car. The right front wheel is the lifted wheel and it is drill at 3/16” up from the bottom of the car. This is so the lifted wheel never touches the track. The rear axle holes are drilled at a 3 degree downward angle into the body. The keeps the rear wheels out at the axle head during the race and also make the rear wheels ride on the edge of the wheel. The front axle holes are drilled straight. The cut-back for the left front wheel (dominant front wheel – steer wheel) is also marked. This cut-back allows the “steer wheel” to run down the rail with-out the rear wheel behind it also running down the rail. You only want the “steer wheel” touching the rail, not any other wheels.

Note: The body is marked“F” for front, “R” for rear, the left front wheel (DFW – steer wheel) is marked “DFW” and the right front wheel is marked “LIFT” for the wheel that is lifted off the track.

DRILLING HOLES FOR WEIGHT

Supplies needed:

(1) Pinewood derby body with axle holes already drilled
Cordless drill
Scale (Post Office?)
Use your own weight. Weight can be anything…. Pennies, lead, tungsten, zinc..… Round weights are easier because you can just drill a hole and put them into the body.
Drill bit that is a little bigger than weight size selected

Tips
Before you cut your body to your final pinewood derby car shape, first cut holes to accept the weight(s) that you have chosen.
You should have to install about 2to 3-1/2 ounces of weight (depending on your car design). Weigh your selected weight and drill enough holes to hold that amount of weight plus a little more. If I was drilling holes to hold 3 ounces of weight, I would make sure my weight holes would hold 3-1/2 ounces. Note: You will need a lot of pennies to make 3-1/2 ounces, lead and zinc are more dense so you will need less volume of them than pennies. Tungsten is the most dense, heaviest weight, but it is expensive.
Drill as many holes behind the axle as possible without interfering with your pre-drilled axle holes. Stay away from your axle holes!!
If I was drilling for 3/8” diameter cylinder weights for 3 ounces of the weight I would drill 3/8” holes all the way through the side of the body as shown below. This will allow for a thin car design.

You could also drill 1” deep holes from the bottom of the body like shown below. This would be for a car with a thicker back section.

Keep your weight low and as much towards the rear of the car as possible. Do NOT glue in your weights yet! First you need to cut the shape of your pinewood derby car. Make extra holes so you can move weight around and get the COM you want when you install the weights later. You can always putty over the holes later, place packing tape over them or just leave them open

SHAPING THE CAR BODY

Supplies needed:

Weight holes drilled Pinewood derby block supplied in BSA kit (You did this already!)
Handsaw, Coping saw, Mitre saw… something that cuts wood
Wood Sandpaper

Tips

Don’t make the front of the car pointed… It will not stage at the starting line very easily and may not trip the finish line sensor. You can make the front of your car narrow if you want to, but leave at least a ¾” flat on the front of the car.
If you have a design where the back of the car is taller than ¾” you should angle the sides of the body at the back of the car so the top of the rear wheels will not contact the body.
Make your car any shape you want… Pack 129 has many awards for themed cars! Have fun!
Make sure you don’t cut into your weight holes or axle holes when you shape your car.
Here is an example of a car body:

Next sand off the “cut back” for the front dominate wheel (DFW). This is the left side view:

This is the bottom view:

INSTALLING THE WEIGHT INTO THE CAR BODY

Supplies needed:

Cut Pinewood derby block supplied in BSA kit (You did this already!)
Use your own weight. Weight can be anything…. Pennies, lead, tungsten, zinc..… Round weights are easier because you can just drill a hole and put them into the body.
Glue (Epoxy, CA, White, etc…)
Ruler or Credit Card
Needle nose pliers
Scale

Installing the weight into the body & Center Of Mass (COM)

Very gently place a finished axle into each of the finished wheels.
Very gently push an axle into each axle hole just a little bit. Do NOT install the axles all the way in the car!!! Just a tiny little bit so they stay in the axle hole. You are not installing the wheels/axles at this point, but you need them a little in place to measure the COM.
Holding the car upside down place the weights into the weight holes. First fill up the back and then work towards the front. Add enough weight so the car is around 4.8 ounces. If you don’t have a scale you can always go to the post office and use their scale. Take your car, wheels, axles and weight and figure out how much weight you need to add to get to 4.8 ounces. Note: If you drilled your weight holes in from the side you will not have to hold the car upside down. You also may have to remove a wheel/axle to insert the weights.
With the car still upside down and the weight in place balance the car on a ruler, credit card, etc.. One person hold the ruler and have the other person hold the car. Mark the spot where the car balances. Your balance point should be between 3/4” and 1-1/4” in front of the rear axle centerline. This location is the cars COM. An example is shown below:

If the COM is not in the 3/4”-1-1/4” range you may need to shift the weight around to a different position. If you cannot get the COM under 1-1/4” because you have a front heavy design that is ok.
Tip: A “COM” that is closer to the rear wheel axle centerline will be faster, but more unstable. A COM that is more further away from the axle centerline will be more stable, but not as fast. A fast car that wobbles will be slow, so an aggressive COM will not always produce a fast car.
Once you are satisfied with the position of your weight and the car weighs about 4.8 ounces then gently remove the wheel and axles. Remove the wheels and axles by grabbing the part of the axle near the axle tip where the wheel does not ride with a pair of needle nose pliers. Gently pull each axle out and place them in a safe spot.
Next glue the weights permanently into place and let thoroughly dry

SANDING AND PAINTING THE CAR BODY

Supplies needed:

Weighted and cut Pinewood derby block supplied in BSA kit (You did this already!)
Different Grades of Wood Sandpaper (Lowe’s, Menards, etc..)
Painters Tape (Masking Tape)
Paint (spray can)

Sanding & Painting

Sand the entire car body starting with a coarse grit and working towards a finer grit. I would recommend starting with around 400 grit and working towards 1000 grit. These sand paper grades are readily available.
Place small pieces of tape over the axle holes. Just use small pieces of tape like ¼” x ¼”.
Paint the car with many light coats.
Let the car dry for at least 24 hours before moving it.
Remove the tape over the axle holes.
Add flare, decals, stickers, etc….. Remember the Pack 129 Theme awards!!
Car body is done!

Pack 129 Pinewood Derby Workshop