|
Weight- Your car moves down the track from the force of gravity. If your car is too light, it will have less inertia in the flat part of the track. Itâ€s important to make sure your car is exactly 5 ounces on race day. Better to be underweight than overweight though. Itâ€s always easier to add weight than it is to remove it on race day.Ensure adequate wheel clearance - When you build your car, make sure thereâ€s enough clearance between the wheels and the body that the wheels can freely spin. If you tighten the axles too much, your wheels wonâ€t be able to spin without making contact with both the car body and the axle hub.
Donâ€t make those wheels too loose, though. If thereâ€s too much of a gap between the car body and your wheels, the wheel will slide back and forth along the axle as the car rolls down the track. This will make it hard for the car to roll straight.How to Cut Your Car - Each year the dilemma around pinewood derby homes is how to cut out your car. If youâ€re lucky you know someone with a band saw.
You could always go with a hand saw, but you wonâ€t get as good of results and it will take you a long time. The biggest problem is keeping your cut level so your car is symmetrical. If you go this route, clamp the car to a workbench or c-clamp it to some scrap wood before you start to cut. This will make it easier to keep the car stable while you cut it.
You can also use the above clamping method but use a jigsaw instead of a hand saw. Itâ€s a lot faster than a hand saw and the guide on the jig saw will help keep the cut level.
Use a power sander (like a belt sander) to sand off the unwanted surfaces of the car instead of cutting them off. This is easiest with simple car shapes, but with a little imagination you can do some great stuff. Checking Your carâ€s alignment - The easiest way to test if your wheels are straight is to raise one end of your kitchen table slightly. Put a book under the legs of one end and youâ€ll have a little slope. Then place a ruler or other straight edge at the edge of the table and line up the carâ€s left wheels against the ruler. Let your car roll and see if it moves closer to the edge of the table or more toward the middle. Make sure you donâ€t let the car fall to the ground! If your car pulls to one side, you need to check your alignment.Make sure your car fits - In order for your car to race, it needs to be able to roll down the track. If there isnâ€t enough ground clearance between the guide rail and your car, your car will scrape the rail and slow down. If there isnâ€t enough space between the wheels and the guide rail, your car will slow down. Check your rules out. They tell you what your carâ€s dimensions need to be.Optimum Weight - Weight should be compact, not spread across the body of the car. Spreading the weight across the body increases the amount of mass that must rotate. By keeping the weight compact, less mass needs to rotate and less energy will be lost overcoming inertia.Axles and wheels - A lot of kits have burrs and mold marks poking off the wheels and axles. Every one of those will slow your car down. Friction is enemy number one to your car. Smooth axles and wheels have less friction.
You can use a file to trim the mold marks off the axles. Then you can use some fine-grit sandpaper to take the rest of the mold marks off the axles and the wheels.
The easiest way to sand the axle is to put it in an electric drill and let the drill spin the axle at a low speed while you polish it.
Thereâ€s three places on the wheel that need polishing. The wheel treads, where the wheel makes contact with the track is the first one. You need to sand off the mold marks. You also need to sand off any mold marks on the inside and outside hubs of the wheel where theyâ€ll make contact with the axle and the car body. And youâ€ll want to polish the inside of the wheel, where the axle runs through. Painting Tips- A few simple steps to a nice paint finish: Â
Before you even start to paint, make sure you have a well-sanded body. Start with a coarse grit sandpaper like 100 and after the car is completely smooth, sand it again with 150 and again with 220. The more you sand the car, the better it will look.
Use a damp (not wet) cloth to wipe all the sanding dust off your car before you start painting and then make sure to let it dry.
Use spray paint. If you brush the paint on, youâ€ll have obvious brush marks.
Use glossy paint. Flat paint just never looks as good. Most things in life are painted with a glossy paint.
Putting primer on the car will help the paint stick to the car instead of soaking into the wood. Your paint will look better, youâ€ll use less paint, and it wonâ€t take as long to paint.
Make a paint box. Grab an old cardboard box and tear one side off. Set your car on a small block of wood and spray paint it. You can also run two lengths of fishing line across the box and set your car on those instead of a wood block.
Spray your car in light, even coats. Better to put 30 thin coats of paint on rather than then put three thick coats. Thick coats take longer to dry.
Follow the directions on the paint can.
If you put stickers or decals on the car, put a coat or two of clear gloss coat on afterward. It helps the stickers blend in with the paint and looks very nice.Lubrication - How to reduce friction? An easy way to reduce friction in your pine car is to lubricate the two surfaces. This is an essential part of pine wood derby racing. Purchase a tube of graphite and sprinkle a little on the axles near the wheel. Spin the wheel so the graphite works in. You will immediately notice a significant improvement in the wheel speed as you turn it after applying graphite.Car Design and Weight Placement - Weights placed on the bottom and in the back seem to make the car faster. You can use a dremel tool to dig out an area on the bottom between the axels to place the "official scout weight" lead block. (purchase at store). You can use a glue gun to keep weights on car. Some types of weights you can use other than store bought: coins, bbâ€s , washers etc.Â
|