How To Build A Cheap Pinewood Derby Track
This page explains how to build two inexpensive pinewood derby tracks: a simple 2-lane track for home use and a high quality 4-lane track suitable for hosting competitions.
How To Build A 32-Foot 2-Lane Track For $20:
A little colored masking tape and checkerboard paper
dress this track up nicely.
The track above, minus the timer board, can be built in less than a day for the same money that the average family spends on dinner at McDonald's. Start by purchasing a 4 x 8 foot sheet of 1/4-inch vinyl coated masonite. Mine cost $16 at Home Depot in 2010. (This price increased to $21 by 2013.) Also purchase 100, 1/2-inch long countersink screws.
Use a saber saw and a very straight cutting guide to cut the board into four pieces that are 8-inches wide by 8 feet long and eight pieces that are 1 3/4-inches wide by eight feet long. If you don't have an eight foot straight edge, cut one of the 8-inch wide boards as straight as you can and use its good edge, the one cut by the manufacturer, as a guide for the rest of the boards. The 8-inch wide pieces will have their edges on the outside and don't interact with the cars so they aren't important. But, the narrow strips are going to be the guide rails and have to be perfectly straight and smooth. I used a fine metal cutting blade in my saw, a high blade speed and a slow cutting pace and came out with edges that were so smooth they hardly needed sanding. The four, 8-inch wide pieces will form the bed of the track. Cut eight, 1 and 5/8-inch wide guide strips from the remaining 16-inches remaining of the board.
Sand the sides of the guide pieces with 220 then 400 sandpaper stretched over a piece of straight wood. You want to take off all the high points as well as smooth the entire edge. The tops and bottoms don't matter but make sure the edges are smooth and even.
Lay the four wide sections end to end and make sure they are straight relative to each other. Place the narrow strips on them in two rows. Starting from the end that will have the start gate, check the ends of the narrow boards where they butt up against the next ones in line. Make sure that the beginning of the next piece of guide rail is the same as or slightly smaller than the end of the piece ahead of it. If the beginning of the second piece is larger than as the car races down the track one of its wheels could hit the edge sticking out and get knocked off the track. Repeat this process with all six guide rail joints making sure they all transition into the next strip without any bumps that could catch the car.
The guide rails are going to be what holds the track sections together. To do so they need to overlap the ends of the 8-inch wide pieces. Starting at the top or "start" end of the track, push the guide rails down 6 inches so they extend out beyond the end of the 8-inch wide boards by 6 inches. Being careful to make them perfectly straight, drill, countersink and screw the 1/2-inch long countersink screws through the guide rails and into the base boards. I put my screws 6-inches on center. The guide rails should be 2-inches apart and centered on the bases. Use the overhanging sections of the guide rails to connect the base pieces together.
To connect the main base boards together, slide the next board in line toward the previous board and butt their ends together.
Screw through the guide rails that overlap the base boards to join them.
The start end of the track is elevated and the first union will be a few inches off the ground so it needs an extra support. Cut a piece that's 8-inches square from the remaining section of the 4x8-foot sheet and attach it to the bottom of the first section of the track so that it extends out 4 inches.
The second section of track will slide in between the bottom support and guide rails. Continue connecting the sections and you're done! Simply elevate the start end of the track and rest it on the back of a chair with an additional support like a box halfway down the incline and you're good to go. A block of wood works great as a starter. The track goes together and comes apart in as little as 15 minutes.
To start a race, simply place a small board across the starting line, place the cars in position and quickly lift the board forward and up at the same time.
If you want a more professional start system, simply attach a piece of wood on a hinge to the underside of the base board under the start point and spring load it with two rubber bands so that they pull it down and back. Cut two long channels in the middle of the track in front of where the cars stage before the race and attach two dowels to the hinged board so that they stick up through the track when the hinged board is held flat against the track. Attach a handle with a release to one side to hold the hinged board in place until it's time to start the race. The following two pictures give you the idea:
The red duct tape holds two pads in place where the hooks that hold the rubber bands strike the underside of the track when the release is triggered. They quiet the loud bang of the hooks colliding with the track.
Strips of masking tape down the center of each guide rail give the track a sharper look. A pillow at the far end of the track stops cars very gently.
How To Build A Two Lane Timer For $30:
Two lane pinewood derby timers cost $160 to $300 in 2010. The following timer only cost me $30:
Purchase two cheap electronic stop watches from the exercise section in Walmart ($9.00 each, you need the type where the same button starts and stops the timer), two roller-type micro switches and two lever-type micro switches from Radio Shack ($3.00 each) and a 100-foot roll light weight speaker wire ($5.00.)
Mount a roller micro switch on each side of the start line with the roller arm set high enough so that when you push the start block forward it triggers the switch.
If you've installed a spring-type release, position the switch so that the hinged board sweeps across the roller switch to momentarily turn it on. You don't want it to be at the end of the board's stroke or it will hold the switch on continuously. Either way, once the switches are mounted connect 35 feet of the speaker wire to the two lugs that are in the normally open condition. You need a separate switch for each lane.
Take the back off the stop watches. The timer's on/off button (green arrow) works by pushing on a piece of flexible metal (red arrow) to make contact with a fixed piece of metal (blue arrow.) When the two pieces of metal touch they complete a circuit that starts the stop watch. When they touch a second time they stop the watch.
Cut a 12-inch long piece of speaker wire and pull the two lines apart. Attach one side of the speaker wire to one of the slips of metal and the other wire to the other piece of metal. Jam a piece of cardboard or plastic between the two pieces of metal so that they don't accidentally touch. Tape the first inch of the wire down so everything stays in place, drill two two holes in the stop watch's plastic back, push the wires through it and screw the back in place. Now when you touch the ends of the wires the timer will start. When you touch them again it'll stop. Twist the ends of the wires to the ends of the wires from the start switch and you're almost done.
Mount the two remaining switches on a scrap of the remaining masonite so that they face forward and are in line with the guide rails. Clip a 2-inch long length of nylon from a very small zip tie and tape it to the switch's arm so that when a car runs off the end of the track it bends the nylon forward and down and in so doing activates the switch. attach wires to the switch and twist them around the wires from the stop watch. Now the start switch will start the timer and the stop switch at the end of the track will stop it. Repeat the wiring procedure for the other side and you have a two-lane timer that's good to 0.01 seconds. While this isn't precise enough for research it's more than sufficient to decide close races.
When this track was built the only stop watches available locally were accurate to 0.01 seconds, which isn't good enough for pinewood derby car research. On-line searches will provide sources for 0.001 second stop watches. These are acceptable for research. The cheapest cost $25.00 plus shipping.
How to Build An Inexpensive, High Quality 4-Lane Pinewood Derby Track:
The success of the super-cheap 2-lane track described above got me wondering if similar materials and techniques could be used to build a 4-lane track good enough for hosting formal pinewood derby competitions. As I began to develop plans, I also decided to address several problems with the professionally made pinewood derby tracks.
Commercial 4-lane pinewood derby tracks run anywhere from $800 to $1200 in 2013 depending on whether you want plastic, wood or aluminum. This expense prevents many clubs from purchasing one. Other problems are that when disassembled they're too big and heavy for one person to handle, are too long to transport for anyone who doesn't have a van or truck and too bulky for convenient storage. The design I present below resolves all these problems. It only costs $100 to build, breaks down into two, 48-pound packages that almost any man can handle and the packages are only 50-inches long by 8-inches thick making them much easier to store than the usual 8-foot long sections of commercially made tracks. The price paid for this low cost and convenience is the time and effort invested to make one, about 40 hours. Here's what the assembled track looks like:
track is 39 feet, 5 inches long, the last 4 feet of which are the
The start end of the track is the standard 48 inches high and the actual
race distance from starting gate to timer is 34 feet 4 inches.
the sides with checkerboard cloth and a race logo enhances the
Here an AWANA Grand Prix logo has been posted. I also have a BSA Pinewood Derby logo.
...this is what it looks like packed up for transportation or storage:
Packaged for transportation, the two units are small enough to be carried in the smallest compact car.
Each package weighs 48 pounds. This may seem a lot for one person to carry but because they weigh the same they balance each other and the carrying slings allow them to be carried straight-armed, so very little arm strength is needed. I'm 63, not in great shape and have a weak back yet I find I can manage these with remarkable ease.
The basic construction is the same as for the 2-lane track. One difference is that the overhanging sections of the guide rails used to connect the bed sections are only 2-inches long and only use one screw each.
This was done to minimize the length of the pieces to facilitate storage and transportation.
Another difference is that there are hinged legs attached to the bottom of the first three track sections to elevate the start end of the track. These legs force the first eight feet of the track into a flat zone with a 26-degree incline, which is standard configuration for most tracks.
two red arrows point to 1x2 inch pine boards used to stiffen the
first four feet of track. Once the track is assembled, the start end
is raised and the legs swung down and locked in
place with the two brass draw catches at the top of the legs. Then the other legs are rotated down. The first legs are 47-inches tall, the second are located 47 inches away and are
28 inches tall, the third 17.5 inches from the second and 21.75 inches tall, the forth 26 inches from the third and 10.5 inches tall and the last is located 41.5 inches from the forth
and is 1.5 inches tall. The legs are made from 2x2s. The final leg is a 1.5-inch thick strip of pine.
Start your pinewood derby track by purchasing 200, 1/2-inch countersink screws, 40, 1-inch countersink screws and three 4x8-foot sheets of 1/4-inch thick white vinyl coated hardboard or MDF board. In 2013 I could only find this material in Home Depot. Lowes didn't carry it. When selecting sheets only buy those that are flat, have clean edges and unmarred surfaces. This was a problem when I built my pinewood derby track. One Home Depot had its sheets placed so high I couldn't reach them to examine them and the sheets were badly warped by only being supported by two arms. Many of them also had badly dented edges. The other Home Depot had sheets down low where I could sort through them and were perfectly flat, but they actually measured 49 x 97 inches and had edges that looked like they had been cut by a maniac with a chain saw. In the end I chose the larger sheets and recut the edges to clean them up. Because I made a mistake cutting the ends square, I had to recut them resulting in track sections that were only 47 inches long, which is why the final track ended up an odd length.
I tried several different blades in my sabersaw and found the Progessor type by Bosch cut the cleanest. Since this is going to be a top quality pinewood derby track it's important that all edges be straight and square. I highly recommend purchasing a good, 18 x 24-inch steel square and an 8-foot metal straight edge for this.
Start by making sure that the ends of the 4x8 sheets are straight and square to the sides. If they aren't, recut them. Next, carefully cut eleven, 16-inch wide by 48-inch long boards. Because the car wheels don't touch the edges of these boards the edges do not need to be perfectly straight and even... but strive to make them so. This will be good practice for cutting the guide rails, which do have to be perfect. Next cut forty-four, 1 and 5/8-inch wide guide strips. These must be as perfect and uniform as possible. I ended up cutting twice as many as I needed because I messed up so many they had to be thrown away. Figure on going through 4 blades cutting the guide rails. MDF is soft but you're cutting over 300 feet altogether so blades wear out.
After the guide rails are cut, sort them into four stacks where they are as similar in width as possible. Next, load up your DVD player with a stack of your favorite movies and get ready for 20 hours of sanding.
While the simple 2-lane pinewood derby track used guide rails that only had a light sanding, a track good enough for competition needs rails that are hard and glass smooth... and that's going to take considerable time. Do one set of strips at a time to avoid mixing stacks.
First up, sand both sides of each strip with 220 grit sandpaper. You'll need at least ten sheets cut into quarters to do this. Work the upper edge, the vinyl coated edge, enough to create a slight curve. Run the sandpaper up and down the length of the guide strip, not perpendicular to it or you may pull off the vinyl coating.
After that's done, stack the guide strips up and place them on a paper covered surface in a well ventilated area. You want them on edge but leaning so that the sides and top curved edges are exposed. Spray them eight times end to end with with Minwax fast drying high gloss polyurethane. This is a non-water based urethane that will not raise the MDF's grain or attack the vinyl coating. The MDF, or hardboard, will soak up the spray like a sponge so by the time you work your way from one end of the rails to the other you'll be able to start right over again. Once you're done spraying, immediately wipe off any spray that puddled on the vinyl coating. Leaving it on wouldn't affect the racing quality of the track but it will look a little sloppy. If you can't get it all off don't worry, the colored tape placed on the guide rails will hide most of it. You'll need four or more cans of spray, depending on how much spray you lay down per pass. I found them for $8 each in Walmart in 2013.
Let the guide rails dry over night. By the next day the polyurethane will have hardened the sides of the rails into something close to tempered masonite. Get 20 sheets each of 600, 1000 and 1500 grit sandpaper and cut them into quarter sheets. (These are most commonly found in the tool section of hardware stores rather than the paint department.) To get rock-hard, glass-smooth sides on the guide rails, sand them first with the 600 grit paper, then the 1000, followed by the 1500, then turn the 1500 paper upside down and burnish the sides of the rails with the paper back. The sawdust produced during this is very fine so be sure to use breathing and eye protection. I also found it useful to make a stiff wooden jig in which to hold the rails. They are too floppy by themselves for efficient sanding. This is by far the most boring and tedious phase of making this track. In hindsight I might have forgone it and stopped after the first 220 grit sanding. It all depends on how good a track you want. While the car wheels roll over the track's bed, they slide along the sides of the rails. Because sliding drag is many times greater than rolling drag this means the side rails have to be glass smooth to avoid ending up with a slow track. Worse still, rough sides on guide rails may enable a car with unpolished wheels to catch on the rail and jump the track. I found half-watching TV while doing all this sanding helped keep my sanity.
Once the rails are done, assembling the beds and rails is accomplished the same as for the 2-lane track.
sure to drill screw holes first. After the first assembly and
disassembly, sand down any raised areas
created by the screws so that the sections go together without gaps. If a hole ever
strips out, simply coat the sides of the hole with wood glue and let it dry. It
will hold the screw fine the next time the track is used.
Once that's completed you need to attach the support legs to the bottoms of the first three sections of your pinewood derby track using strap hinges. The shorter pair on the second section of track are narrower so that they nest inside longer, overlapping legs to create more compact storage when collapsed.
The last piece to be made is the stopper section. Although it's tempting to assume this is the least important section because it only sees action after the race is complete, it is really the most important section of any pinewood derby track. The reason is that poor stopping systems, like the pile of bean bags I saw at one pinewood derby race, knock the cars around so violently that they are often damaged. I've seen wheels torn off cars this way. Without a gentle stopping section high performance cars, which are very fragile, can be destroyed in the first race. The best stoppers have the cars race smoothly onto a section where the floor drops away so that cars slide on their bellies over the guide rail to a stop. The best surface for the guide rail is the textured rubber strips available from FastTrack.com as a replacement part. I've experimented with 11 other types of rubber and high friction materials and nothing works as well.
Note that the top of the guide rail is level as it transitions from the race track to the stopper section. You don't want any angles or bumps because the cars are moving fast enough for any irregularity to catapult them into the air. Because the rubber stopping material is so thick, I cut part of the supporting rail under it down to maintain a flat surface transition. Shimming up the end of the last section of track not only provides enough clearance so the wheels come off the track's bed, but also raises the bed for the timer's infrared lights.
Like the 2-lane track, the starting gate is simply a strip of 3/4-inch plywood with four, 3/8-inch diameter wood dowels mounted in it.
The track gate posts are wood so cheaters can't get a boost on release by mounting magnets in the front of their cars.
The colored lines down each guide rail aren't only for decoration, though they do a great job of brightening up the track. They help the people watching the race identify which track their car is on. They also help the people running the race keep track of which lanes cars have run on so they can follow the proper rotation. I used vinyl tape on this track and discovered it was a poor choice. It's almost impossible to apply without stretching it. As it rests on the track the adhesive is soft enough to let it slowly pull in on itself, causing the tape to shrink. This results in gaps at each break in the track. These can be colored in with felt pens but the gaps are still visible. If I had to do it over I'd take the time to find colored masking or non-stretching acetate tape.
gate looking up under the track. The 7-inch linear bearing was made
by cutting down a 16-inch bearing from a kitchen drawer.
The red arrow points to the metal finger that closes the timer switch (green arrow.) When the wood handle on the end of the bearing
is pulled back gravity causes the 1x2 inch board on which the four wood gate dowels are mounted to swing down, releasing the cars and
signaling the timer to start by opening the switch.
bearing has been pulled back allowing the gate to swing open
releasing the cars. Attaching a sheet of plastic on the 1x2 where the
linear bearing rubs and beveling the end of the linear bearing enables it to smoothly and easily push the gate up.
Gravity causes it to swing down while the rubber band stops it from bouncing back up and hitting the cars. If you've even been to a race where the cars seem to jump or bounce up when released, it's usually caused by the gate bars bouncing back and hitting them. The catch and release mechanism is a section of a linear bearing with a piece of wood at one end as a handle and a downward sloping taper cut into the end the holds up the gate. The bearings are available in the kitchen drawer hardware section in hardware stores for $6. To get the travel distance right and still have it fit under in the length available at the end of the track, I have to take the bearing apart, cut the ball bearing race down by 6 balls and cut the length of the bearing down to 7 inches. I can't provided exact details on how to do this because it depends on what type of linear bearing is used. If this is not the type of release you like, then the rotating handle type mentioned in the 2-lane track may be preferable. I like the linear bearing release because it fits inside the track's frame when folded up for transporting.
A close-up of the timer release switch. When it opens, the timer starts.
One of the nice features of the white vinyl surface of this pinewood derby track is that it shows off the lane colors better than aluminum or plastic tracks. It also makes the cars stand out better, particularly those with subdued paint designs.
For storage and transporting, I discovered that the the two packages come out weighing the same if one of them holds the flat sections while the other holds the first four sections with the support legs. Although the package with the legs will be thicker, because much of its volume is air, it actually weighs the same other, thinner package. To hold the two packages together and protect the ends of the track sections from getting damaged, buy four, 16-inch cardboard boxes and modify them to fit snuggly over the ends of the packages. For extra padding I doubled the thickness of the cardboards on the ends. For the end caps to fit the order of stacking needs to be the same every time the track is stored. The empty spaces between the legs are convenient places to carry assembly equipment, the foam end stopper and screws. To carry the packages I sewed two slings made out of heavy canvas with 7/8-inch dowels running through the sleeve provide even support along the full length of the slings.
Assembling the track takes one person 25 minutes. The process is made easier by purchasing a small electric screwdriver. I always carry a spare regular screwdriver in case the electric one fails. An organizer is very helpful.
Once the track is completed it's important to grind down the tips of any screws that might be poking through the bottom of the track otherwise they will scratch whatever floor on which the track is assembled. Color coding the screws and keeping them sorted for each section insures the right screws always goes into the right hole.
In the vast majority of races it's obvious who placed first, second, third and forth so timers aren't really necessary as long as a clearly marked finish line is provided. I found the checkerboard finish line of the two lane track made judging close races difficult. A much better solution is a solid black line.
Nothing makes a track more impressive than a good timer. There are several available. For myself, I preferred the doublesided Smartline timer with elapsed time offered by eteckgadgets.com. I believe it's the best buy for what you get. $550 is a lot of money, but in fact is very reasonable. Remember, you're not just getting four timers, but the software to compare the four times and decide which was the fastest. I like to think that by building my own track I saved enough to buy a good timer. This timer is easy to modify to fit any track configuration. Installation only requires four holes to be drilled in the track near the finish line into which the infrared signalling LEDs are mounted and a microswitch to be mounted on the release gate to signal the unit when the race starts. Both are easy and simple tasks.
Although the timer was set up to be powered by wall power, I prefer to use a battery pack so there isn't an electric cord on which children can trip. Two 6-volt batteries connected in series provide the needed 12 volts for over 4 hours of racing.
I cut off the
power plug from the timer's power converter and wired it to the
batteries to connect the batteries to the timer.
Be sure to get the polarity right!
I find this track runs much faster than wood tracks, the same as a brand new plastic track and almost as fast as the best aluminum tracks. Here's a video of it being used for the of the 2014 Grace Chapel AWANA Boys Grand Prix finals:
All in all, over 40 cars raced on this track during the event and not one jumped out of its lane. More importantly, all heats ended with every car placing in the same position regardless of the lane on which it raced. This verifies the consistency of the track.
Building a good 4-lane pinewood derby track is challenging and time consuming. But it's also one of the most satisfying projects I've ever completed. Using the track for races, whether small family get togethers or large pinewood derby races for the local scout clubs, is a lot of fun. I've even enjoyed many hours using it all by myself developing ever faster cars.
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