Slow Races On A Pinewood Derby Track Built From Scratch

Pinewood derby racing is a popular pastime for scouting groups and many others besides. [Mr Coster] whipped up his own track with the assistance of some 3D printed parts, and used it to run a competition with a fun twist on the usual theme.

The track starts with a pair of MDF panels, on to which some strips are placed to act as guides for the racers. There’s also a release mechanism built with hinges and a pair of dowels that ensures both racers start the competition at exactly the same time. To give the track a nice transition from the downward slope to the horizontal, a series of curved transition pieces were designed in Fusion 360, 3D printed, and added to the course.

As for the competition, [Mr Coster] decided to eschew the usual focus on outright speed. Instead, students were charged with building the slowest possible car that could still complete the course. Just for the fun of it, though, the kids were then given one day to modify their slowest cars to compete in a more typical fastest-wins event. It gives the students a great lesson in optimizing for different performance parameters.

You might be old-school, though, and want to ruin the fun by taking it all way too seriously. Those competitors may wish to consider some of the advanced equipment we’ve featured before. Alternatively, you could run a no-holds-barred cheater’s version of the contest. Video after the break.

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An Open Source Pinewood Derby Track

There are a lot of reasons to consider reproducing. Tax breaks are near the top of the list, and a bizarre obligation to ensure the survival of the species following closely behind. The pinewood derby, though… Where else are you going to get a chance to spend hours polishing axles and weighing down bits of wood so they can roll faster?

The Lansing Makers Network has cub scouts around the shop, most likely goofing off while their fathers spend hours building their son’s pinewood derby racers. Where there’s a pinewood derby manufactory, there’s a need for a track to test these racers out.

blurry-scoreboard-gutsThe four-lane, 38-foot run was made out of five sections of cabinet plywood attached with 4″ lap joints. That’s the way to do it if you want a smooth running surface. The lanes are 1/4″ strips of maple plywood, and the last four feet of the track – after the finish line, of course – are a ramp that raises the lanes another 1/2″ above the ground. There’s very little need for a bunch of pillows or foam at the end of the track.

This is the 21st century, and no pinewood derby track would be complete without a few bits of electronics. The starting gate is activated with a push button. A solenoid keeps a quartet of pins in place until the race is started. When the start button is pressed, the solenoid releases, sending the cars on their way.

On their way down the ramp, the cars pass over an IR object sensor which records their starting time. Thanks to some more sensors at the finish line, the track records each car’s position in the race on a few seven-segment displays.

Wood-Only Kart Race Inspires Fancy Wooden Bearings

The mountainous Italian town of Artena holds an annual soap box derby for wood vehicles – and they mean 100% wood, not a speck of anything else. Fierce competition led [Alessio] to engineering and CNC fabricating these gorgeous wooden roller bearings for the wheels to give him an edge.

Thousands in costume attend the renaissance faire known as “Palio delle contrade di Artena”, and the popular wood-only race is called “La Carettella.” The karts are operated by a two-man team: one in front who brakes, the other in the rear who hops on and off to push as needed throughout the course. There appears to be no steering from the wheels** so turning is also a two-man effort. The wooden levers dragging on the pavement provide some steering from the “driver”, and the push-man often manhandles the entire rear end, drifting where necessary.
HAD - Carettella2The course also includes full-width obstacles like hay bales. Teams are divided by community or “contrada”, and it was [Alessio]’s team captain who came to him with the special request of roller bearings. Unable to find evidence of other wooden bearings, [Alessio] knew he would have to invent them himself – so he did.

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Derby the Dog

Derby’s Got Legs, He Knows How To Use Them

There’s just something about the holidays and man’s best friend that brings out the best in people. [Tara Anderson], Director of CJP Product Management at 3D Systems, fostered a husky mix named Derby.  Derby was born with a congenital defect: his forelegs were underdeveloped with no paws.  This precluded the poor fellow from running around and doing all of the things dogs love to do.  [Tara] had fitted him with a wheel cart, but she still felt that Derby deserved more mobility and freedom.  Deciding that 3D-printed prosthetics was the answer, she turned to her colleagues and collaborated with Derrick Campana, a certified Animal Orthotist, to create a new set of forelegs for Derby.

The design is different from typical leg prosthetics; Tara felt that the typical “running man” design would not work for a dog, since they’d just sink right into the ground. Instead, the “loop” design was used, allowing for more playful canine antics. They were constructed using MultiJet Printing on the 3DS’ ProJet 5500X.  MultiJet Printing enabled the prosthetics to be printed with firm and soft parts, both needed for comfort and durability.

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