How to Create a Pinewood Derby Car

Intro: How to Create a Pinewood Derby Car

Well, here it is Pinewood Derby time, again, for our Pack.  We hold the Derby in January and hand out the car kits at November’s Pack Meeting.  Each year the Cubs need to create a new car.  They can’t use last year’s previously experienced car.  We run two sets of races.  Cubs race against Cubs, and Open Class, is for everyone else.   Now I will show you how I set about creating a Pinewood Derby Car for the Open Class, although everything I show will be allowed for the Cubs cars.  Remember that there is no “Pinewood Derby Car Police” which will rule on how the car is created.  The cars are only judged on whether or not they meet the stated, race time, requirements, as found on the paper included with the kit.  Here we go!

STEP 1:

Supplies:
Car Kit
Sand paper (Grade, 120, 140, 180, 220)
Knife or hack saw or rotary tool
Pencil
Spray paint
Scissors
E-6000 glue
Paper cups (to set the car on while being painted)
Digital scales
Screw driver
Drill
Square file
Hammer
Terry cloth
Pumice
Square (to see if the axel channels are square to the car, if not, you will need to redo them)
Boby tool,
Wheel mandrel
Axel press

STEP 2:

If your Pack provides you with a kit, use that.  Otherwise choose a kit.  You can use an official BSA kit or ones available at local craft or hobby stores.  I chose the one in the middle, except I hate the solid piece axels, so I traded for the nail axels in the kit on the left.  Also the completed car, with added weights, needs to weight no more than 5oz (or 142 grams).

STEP 3:

First thing you need to do is see if the axel channels on the bottom of the care are square to the car.  If they are not, fill in the channels with wood filler.  Once dry, sand it down and re drill the holes using this, a body tool.  Follow the directions with the tool.  Mine were straight so I didn’t have to use it this time

STEP 4:

This kit has a wedge shaped piece of wood.  I like wedge shaped cars.  One less step makes me happy.  I decided to actually follow the instructions in the kit (up to a point) this time.  So I cut out the templates for where to cut the cut and where to place the plastic pieces.  I laid them on the wood and used the pencil to draw where I wanted to cut wood away.

STEP 5:

A certain tool was out in the shed in the back yard, and it was snowing, so I choose not it use the hacksaw to cut away pieces of the car.  (If I were helping a boy make the car, I would have made the trip.)  I pulled out a box cutter that I am familiar with and started to whittle the places I wanted gone a little at a time.  (If your Cub hasn’t earned his Whittling Chip Card, don’t let him anywhere near a car with a knife, with or without adult supervision.)

STEP 6:

Once I decided, I had carved enough off, I took a piece of sand paper wrapped it around a block and started sanding, until every part of the wood was wonderfully smooth.

STEP 7:

I cut the plastic pieces available in the kit out and sanded the cut edges smooth on another piece of sand paper.

STEP 8:

At this point, I got out my digital scale and weighed the car body, with wheels, axils, and plastic parts, to see how much weight I would need to add.  The kit I choose included weights, so I determined that 2 strips of weight with their screws would bring me within 6 grams of 142 grams.

STEP 9:

I decide to have the weights recessed into the bottom of the car. I used the pencil to trace where I wanted the weights to be and I, again, hand carved the hole (half the depth of the weights) with my box knife.  I tried the rotary tool, but that did not make me happy.  I sanded the bottom of the hole, smooth, before I screwed the weights into place.

STEP 10:

I consulted the instruction sheet, again, and after deciding to make a couple of changes, I glued the plastic pieces to the body of the car.  I let the glue dry for 12 hours.

STEP 11:

I had decided to paint my car hot orange. It turned out to be a big mistake. Okay, it was ugly.  I repainted the car with some black spray paint I had left over from another project.  I sprayed a coat, and let it dry.  I did a second coat and let it dry.  I then, I turned it over and repeated the process on the bottom of the car.  I let it dry overnight.

STEP 12:

Once dry, I applied the dry transfers included in the kit, to the painted car body.  Hurray the car body is done!  Not too bad, not perfect, but then I never was one who could do perfect.

STEP 13:

The wheels can be worked on while the glue and/or paint dry.

The wheels and axels can make or break a car.  You will need to remove any seams on the wheels themselves and make sure that the axels are straight and shiny smooth.  The nails that are used for axels have little seam burrs near the place where the head and the stem of nail meet.  These will need to be removed and the part of the nail stem here the wheel will have contact will need to polished smooth.

STEP 14:

Our Pack has a “KIT” that can be checked out for 24 hours by people making cars.  This kit has tools that help correct the problems that the wheels and axels can have.  This kit also allows all the boys to have equal access to having a “FAST” car.

STEP 15:

This is a mandrel that holds a wheel on to a drill.  While the wheel is spinning, hold a piece of sand paper to the flat side of the wheel (where the wheel meets the track) to remove any seams and any divots that may be on the wheel.

STEP 16:

This is an axel press.  The nails used for axels are just that, nails, and they are not straight.  We use this press to make our axels straight.  You put the axel in the axel press; then mark the head of the nail with a permanent marker. Turn the press on its side and rap it 2-4 times with a hammer.  Rotate the nail head 40°, rap.  Rotate the nail head another 40°, rap.  Do this to the other 3 axels.

STEP 17:

These are polishing tools for the axels.  Put your axel in the drill.  Use the square file and while the axel is spinning, use the file to remove any major burrs.

There are 4 different grits of sand paper, 120, 140, 180 and 220.  Start with the coarsest sand paper, get it lightly wet, wrap it around the axel and holding tight, turn on the drill and run the sandpaper up and down the length of the exposed axel shaft.  Repeat with each grade of sand paper, going from coarsest to finest.

STEP 18:

The last thing to do is to take a piece of terry cloth and wet it, apply a bit of pumice.  Wrap it around the axel shaft and run it up and down the shaft while it is spinning.  This is the final polish.  Repeat all polishing steps with the other three axels.

STEP 19:

Place your wheels on the axels, and gently tap them into the axel channel.  Do this with all four wheels.  Oh no, I have a problem. One of my wheels won’t stay in place.  What to do, what to do!  Light Bulb!  Sugru!  I even have black. I made sure all 4 wheels were exactly where I wanted them, they spun freely without any friction hot spots.

STEP 20:

I opened a pack of Sugru, warmed it up, and made two small snakes

STEP 21:

I pushed the Sugru into the axel channels with my fingers.  I used the box knife to remove any that might get in the way of the wheels.  I let it dry for 24 hours as directed.  Final car weight in was 138 grams.

STEP 22:

Done!

Now, I rarely win many races, in spite of all my efforts, and I really don’t expect to do any better this year.  But this year I will have the hottest looking car there! Woot!

Comments

[BluesBayou]

We have the boys build sanding stick for this step. Trace out a craft stick on the back of the different grits of paper, then cut them out and glue the cut outs onto the craft sticks - this way little fingers aren't too close to spinging drill parts..

[dimtick]

this comment comes a little late.
one thing that i did with my sons car is that instead of mounting the weights to the bottom, i mount them to the top and as far back as possible. the idea is this puts the weight higher off the ground and will give you a little extra gravity boost.
in case you didn't do it you should put some graphite lubricant on the axels and on the side of the car where the wheels hit the wood. i'm guessing you did this but i didn't see it in the write up.
:)

[craftknowitall]

Never too late, someone is making a pinewood derby car, somewhere, so something new is good. I didn't thing of the graphite, because our Cub Master does it to all the cars the day of the race. So Thanks for the additional info. And thanks for looking.

[thrashermanTotalDIY]

I made one too! i'll post a picture soon it's almost finished

[craftknowitall]

I am excited to view it! Thanks for looking.

[thrashermanTotalDIY]

ur welcome!

[thrashermanTotalDIY]

it's a hummer i got a new camera so i'm tryin to learn how to upload pix to comp.Thanks!

[pliska]

Dremel tool works great for this.

[craftknowitall]

Thanks for all your suggestions. I am not comfortable with the Drimel, I'm not sure why. We bought the tools as a Pack because we have many single Moms and their personal tool list is limited. I usually lend them my drill and the tool kit. We offer to cut the car to the design the Cub draws on the sides etc. We do the best we can to help as we can without doing it all ourselves. Thanks again for your comments.

[hjjusa]

I missed Cub Scouts and went directly to Boy Scouts, but my little brother was in Cubs and he asked me to help him to build his pinewood derby. I Built the most areodynamic one I could, But when he saw it he cried cause it was too light and back then any kind of weights were illegal so I screwed up his car but it sure looked good!

[craftknowitall]

When my son was in Cubs, I was a single Mom, his cars didn't win either. He is now a Cub Master and he says he doesn't hold it against me. He plans on making his own car this winter for an early spring Derby. I am so proud of him.

[pliska]

I recommend recessing the weights about a millimeter when going under the car with them. That way they are sure not to drag on the track.

[pliska]

I used a heavier wood one year and cut it to specs. This allows for more balance in the weight of the car. It was easier for my son to work as well since it did not scratch an ding as much as the soft pine.

[pliska]

As an alternative. I used my drill press to square up the axle holes. Make sure you are using the right size bit by doing a test drill in scrap wood.

[artisnotfart]

Oh my. I am completely prepared to lose to you!

[craftknowitall]

LOL, Thanks!

[mikeasaurus]

Great design! I used to race these derby cars all the time when I was a kid (I didn't win ever either).

[craftknowitall]

I bet you learned stuff while you made your cars, didn't you? I know I do and I have been in Cub Scouting going on 20 years. Have a Merry Christmas!

[mikeasaurus]

Cub Scouts was great for this kind of thing, learning how to do it yourself and then seeing how everyone else made theirs. I was always more of a fan of the designs than the speed, but both were fun!

[PinewoodDerbyDen]

The PinewoodDerbyDen.Com Has a lot of links & Tips for Pinewood Derby also.