Sam (from last week’s session) built this zip line and left it as a present for the older kids. Leo would just like to say “Wheee!”

All vehicles must be on the trailer by 12:30 today in order for us to have time to drive them in the parking lot of the local grammar school.

The TSRL (Tinkering School Racing League) rules require every vehicle to have a working brake, so Hanna and Isaac are taking care of the (hopefully) last detail on the chopper.

Spencer would like Theo to hold his eye open while he touches a modified brush-bot to Theo’s eyebrow.

“It’s not going to actually touch your eye,” says Spencer.
“It’s too weird,” says Theo.
Then Spencer demonstrates for us that he doesn’t actually need mechanical assistance to make his eyes jiggle.
“Dude,” says Theo.

Isaac straps on all the safety gear and takes the Bad Dogs’ chopper out for a spin.

The first thing we notice is that it suffers from too many foot pedals (turns out you need a foot to put on the ground when you are starting, stopping, or turning).

The foot pedal doesn’t give the rider enough leverage to hold the spinning hub of the driveshaft against the wheel. Gever gives Isaac a hand and holds the motor mount down sufficiently for Isaac to complete the test drive.

So the team, Hanna, Isaac, Gabe, and Gever head back down to the shop and start madly re-routing cables.

The Dorkfest car is working through some tricky cabling issues of it’s own. Theo is checking to see if you can still get in and out of the car with the new clutch line running through the driver compartment.

Spencer and Jacob have started brewing their own hydrogen/oxygen mixture.

“Much of the oxygen is reabsorbed in the water,” Jacob is quick to clarify.

Leo is nominated, and reluctantly agrees, to take the car out for it’s first real drive.

“It’s a dangerous job,” he says, “but I’m doing it for the team.”

Theo and Maxine get him tied in with the 3-point seat-belt.

The experimental rack-and-pinion steering works perfectly the first time! The Dorkfest team cheers, and then loads their car on the trailer and heads up for lunch.

The Bad Dog’s chopper has suffered a major setback. During the re-routing of the accelerator, something inside the motor/carburetor slipped and now the cable is no longer affecting the fuel flow.

With the departure deadline already passed, a broken motor, and an unmounted handle for the accelerator, the team decides to put the chopper on the trailer with the hope that it can be resurrected track-side.

While final prep for the Dorkfest car and the Bad Dogs’ chopper is underway, Leo catches a little nap in the dappled shade of a California Cypress tree.

It’s a high-stakes round of Roshambo to figure out who drives first. In an unexpected, come-from-behind mini-victory, Spencer is the winner.

There is a giddy swagger in his step as he heads over to get fitted for safety gear.

Gever tops up the tank on the Dorkfest car. Over the course of racing today, only three cups of fuel will be consumed. Still, the consensus is that next year we will do vehicles with zero carbon output.

Spencer, his senses stretched to the limit, waits for the moment when Leo gets the engine to sputter, then catch. At the first firing of the tiny pistons, he stomps the accelerator, pouring fuel into the carb, then buries his toe in the clutch plate - and roars away!

Spencer leans hard as the Dorkfest car comes around the corner holding it’s line flat and true, trailing a blue cloud mixture of exhaust, wood smoke (from the makeshift motor bearing), and burned rubber (from the drive hub slipping on the wheel).

The rain-gutter / dip in the road bounces him almost out of his seat and when he comes down, the seat support gets cracked. This necessitates a pit-stop and the judicious application of a tensioning strap to support the seat.

Next up is Theo. Years of driving weird vehicles at Tinkering School gives him confidence and a relaxed grin fills his face as he takes the car around the track.

Next up is Leo, who is lead out of the gate, by his sprinting brother Isaac.

“Woo hoo!”

The combination of the slippery seat, the grippy rear wheels, and super-effective steering system, almost slides Leo out the side of the car when he puts it in a tight turn.

In a brilliant stroke, Maxine tapes her camera to her chest to capture her ride.

Theo, attendee of many soccer camps, knows his sprint speed to be between 13 and 15 miles per hour. Maxine’s long legs allow her to get the best clutch pressure (which translates to positive driveshaft to wheel contact) and as she comes around the track on her second lap, Theo sprints along side and clocks her at better than 12 miles per hour.

“I can’t keep up with her for long,” he says.

Jacob gets his lanky body into the drivers seat and gets his turn at the wheel. Just in the nick of time as it turns out since Jiro has to take him to the airport in 10 minutes.

The Dorfest team graciously allows the Bad Dogs to go for a ride in their car. Spencer sprints along and notices that the car is not going as fast as it used to.

Hanna gets in for what turns out to be the last lap of the Dorkfest car. The makeshift bearing has burned completely out, the hot drive shaft has carved a hole the size of a Clementine orange in the motor box - Hanna and Jiro push the cart back into the pit lane for it’s retirement.

They are already late. Jiro tries to pry himself away from the 2008 Tinkerers, making the rounds for hugs and exchanging email addresses.

Not being from California, Jacob is not used to hugs so Leo falls against him as Spencer sneaks up from behind.

After monkeying with the carb, and attaching the new accelerator handle with actual baling wire and duct tape, the Bad Dogs get their chopper running!

Gever tops up the fuel tank with another half-cup of gas/oil mixture and they are ready to go.

Isaac immediately discovers that due to a lack of chassis rigidity, the chopper is very wobbly on the turns, but still super-cool.

Hanna takes the chopper around the track, and starts to get the wobble under control.

“It takes some practice,” she says after two laps.

No, it’s just out of gas. The bearing is holding, but the welds on the driveshaft are getting broken by the clutch pressure. Leo’s ride is cut short and the chopper is walked back to the pits for assessment and fuel.

Theo’s vehicular skills are demonstrated by his commitment in the turns as he lets the bike lean over and allows on the speed to get him through and upright again.

Earlier in the week it was discovered that Maxine had never actually driven a car. Robyn has to take the little Honda back to the house to tell the parents that we are running late at the track, so we decide to let Maxine drive the Honda around the track to see how it compares to the Dorkfest car.

Looks like Maxine likes driving. Our apologies to her parents if we have created a monster.

Spencer overcomes a huge list of personal misgivings regarding the safety and construction of the chopper to take it out for a lap.

“One lap is enough,” he says.

Emboldened by her first automobile experience, Maxine takes the chopper out for it’s last trip around the track. As she enters the pit lane on her last lap, the driveshaft welds fail completely and she coasts in with the engine screaming and the chopper rolling to a halt.

Back at the house, Maxine’s sister goes for a ride in the Dorkfest car.

Looks like she likes it too…

It always ends like this, with long silences, unsaid farewells, and non sequitur references to earlier jokes or incidents. Parents arrive like aliens, and kidnap them one after the other, until only Theo remains.

Ladies and gentlemen, friends and family, I am proud to present the class that built the most complicated projects in Tinkering School history. Left to right, front to back: Theo, Maxine, Hanna, Isaac, Gabe, Leo, Jacob, Robyn, Jiro, and Gever.

I miss you all already.

Isaac “The Chalupa” tests the alignment on the Bad Dog’s chopper.

Gabe, his ever-present hoodie in place, works out the kinks in the Chopper fender.

Drawn by the rare glimpse of sun, Leo grabs an after-lunch nap.

Perhaps jealous of Leo’s ability to nap, Gever tries out Leo’s favorite spot.

Theo has created a logo / emblem for the Dorkfest car.

Any increase in the quality of images today is due entirely to Julie’s mad skillz.

Robyn and Jiro help Theo get the Dorkfest motor mounted on the back of the car.

Isaac and Gever get the chain threaded through the gears and into and out of the motor box. This was the stage when we started to worry about whether the gear reduction was going to handle the RPM from the weed-whacker.

Isaac suddenly realizes that Julie is taking pictures.

The helmets are dusted off and everyone digs through the pile to find the ones that fit.

The strange force vectors involved at the handlebars lead Isaac and Gever through some tricky bits of construction.

Some idle tinkerers decide to try to upgrade the failed flap-drive with some ideas taken from pictures of kayak peddle systems. Julie and Robyn call the new system the “flip-drive” - Hanna is dubious but curious to see if it can work.

Maxine and Gever take a juice-box break.

Gabe adds some rigidity to the tail of the chopper.

Theo and Leo run a long wire up to the steering column to enable the occupant to kill the engine.

Leo is fascinated by fire and everything that could possibly make fire - like the soldering iron.

Forgetting that Homeland Security is not going to let him on an airplane with a bike chain sealed around his wrist, Jacob uses the chain tool to lock the bracelet on.

It’s pizza night and the excitement of the vehicle build has the gang running at high buzz.

After the ice-cream celebration, we manage to get another hour of tinkering in - finally ending at 11:15. Isaac is mounting the new foot pegs on the chopper.

Leo is hypnotizing himself while shaping a metal plate on the grinder.