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.

The Red team, having rejected their earlier name, have adopted a new name: Dorkfest. Gabe (visiting from the Bad Dogs team), Spencer, Leo, Jiro, Theo, and Maxine are working on the single most sophisticated vehicle in Tinkering School history - brakes, gas, rack-and-pinion steering, metal emblem, rear-mounted motor - it’s amazing.

Despite an incredible list of minor set-backs, the Bad Dogs get the chopper working - one of the more elegant and simple designs in Tinkering School history. The biggest problem is that the drive has to hang way off one side.

Evidence of the complexity of the build today is evident by the kinds of parts we are using.

Theo demonstrates the proper tubesledding form.

Leo catches the early morning rays (yesterday).

It’s time to discuss tomorrow’s build - motorized vehicles. Very exciting, but also many ambiguous design trade-offs to weigh.

Gever accidentally suggests and then has to sketch possible ways to build simple rack-and-pinion steering mechanisms. The sketch turns out so good, it convinces one of the teams to try it. He fervently hopes that this is not a repeat of the flap-drive proposal.

Down at the other end of the table, the Bad Dog team discusses the pros and cons of building a PVC tubing chopper.

Gever and Jiro take the tinkerers through the basics of internal combustion, clutches, transmissions, and differentials - of which, the latter two will not be found on our vehicles since we are using scavenged weed-whacker motors.

Jiro takes Isaac, Gabe, and Spencer through a tear-down, clean-up, and rebuild of a faulty fuel system on a two-stroke Craftsman weed-whacker motor.

Before we begin to build, the officials from the TSRL (Tinkering School Racing League) review the the requirements with the teams:
- Must have brakes.
- Must have steering.
- Must not have impalements.

Maxine and her team do some pre-visualization of their vehicle to make sure that it will fit every person on the team and all of the required elements.

Jacob and Gever refine the steering design for the Bad Dog chopper.

Leo and Theo (of the team that couldn’t pick a name so let’s just call them the Red team for now) work on the steering system for the Red team’s four wheel F1 derived car. Maxine is waiting for the drill-press so she can finish mounting the drive wheels.

Despite the amazing comforts of the scavenged Ikea steam-formed plywood seats, the Bad Dogs decide that they are just too heavy for their super-light chopper.

Gabe hangs on to the chopper’s drive wheel while Isaac checks the length of the chassis. There is a lot of discussion about the proper length - room for a seat, the steering, places to put your feet, a fender to protect the rider from the wheel - it’s a lot of stuff, plus there are concerns about the rigidity (or lack thereof) of the PVC.

Using a classic box-frame to pinch the wheel axles, Maxine gets the Red team’s cart up off the ground and into the it’s-a-little-bit-hard-to-work-on-now-that-it-rolls phase of construction.

The Bad Dogs have settled on a length and they are drilling screws to prevent any further discussion. Gever steadies it, Gabe centers the tubes vertically, Hanna keeps the nose of the chassis aligned, and Isaac drills guide holes and drives screws.

The Red team’s front-end has a half-dozen screw tips poking through that require the angle-grinder to remove. Gever loves his angle-grinder and is only too happy to make pretty sparks.

Gever loves sparks and he recommends opening this picture for a closer look. Just marvel at the mid-air explosions - it’s fantastic!

It appears that he just can’t get enough of these beautiful spark pictures.

The weed-whackers have an amazingly simple, but also very awkward way of connecting to the drive shaft - a spinning shaft that ends two-inches shy of the outside of the motor housing has a square hole in the center where the drive shaft is supposed to be held in by external forces, perhaps some kind of magic, or divine intervention.

In last night’s design session, the Red team arrived at the novel idea of mounting the motor on the front fork of the chopper to create a front-wheel drive motorcycle. This idea fell by the wayside as the logistical problems of mounting the motor became evident.

Isaac checks out the stability of his team’s chopper. They will have to stiffen the chassis tomorrow, but otherwise it’s looking, and feeling, bad (as in good).

The weed-whacker motor housings are a little hostile to external mountings, so the teams will have to create wooden harnesses that accommodate the strange shapes.

Leo, Maxine, and Theo discuss steering wheel placement on the Red team car while Isaac tries not to think about the fact that their motor is 1cc larger than the Bad Dog motor.

Able to help out in many ways, leaves a very small carbon footprint, pretty good with a screwdriver and drill, it’s H the generic Hero. Who can this very useful, friendly, funny, smart, talented person be? The world will never know…

Oh wait, it’s Isaac!

After dinner everyone has made their way back down to the studio for some casual tinkering (Jacob and Spencer are making tiny amounts of hydrogen by electrolysis, the Red team is making a plan for the next day, the Bad Dogs and working on a new steering bearing) and Gever, Isaac, Theo, and Jiro head to the metalshop to finish up the drive shafts (pictures of those tomorrow).

Robyn (who will be quick to point out that it was actually Gever) has introduced Tinkering School to the game of Mexican Train and it’s become somewhat of an epidemic.

Maxine takes a turn at sewing. Our hope is that we can hold the seam closed with thread, but then weld it water-tight with wax.

Maxine claims that she really prefers repetitive tasks that allow her to get something cool done with out having to make a lot of hard decisions along the way. “You just like to space out,” counters Hanna.

Gabe is determined to get the foot-pedal steering system working, but his teammates are just a little too sleepy to concentrate on the problem.

Isaac takes a turn at the needle to sew tops onto the catamaran pontoons. There is some concern that the pontoons will sit too low in the water and have a tendency to fill up and sink if the tops are not closed.

There’s a little bit of a backup in the wax application process, so Maxine is waiting patiently (and probably spacing out a little too).

In an effort to get done before lunch, we put four brushes to work on the biggest boat. Maxine, Gever, Gabe, and Jacob are all old hands at this now, and the boat gets done in record time.

It happens to first-timers. They just don’t know how to pace themselves for the non-stop building frenzy that is Tinkering School. Leo has fallen asleep on the deck of the studio, wrapped in a piece of canvas and surrounded by half-built rudders and paddles.

Hanna gets the task of cutting out the deck plates for the catamaran.

The outrigger has been decorated with thornless blackberry leaves.

We move the hulls to the shade while we take a break for lunch. Left to right, outrigger main hull, outrigger, pontoon, pontoon (the latter being the basis for the catamaran).

The outrigger main hull also has it’s own decorative motif.

You never know when it’s going to sneak up on you. Leo seems particularly susceptible.

Fitting two twin-hull water craft and a kayak on the truck and trailer turns out to be a little complicated. Jacob takes a moment to adjust a paddle.

Theo’s father, Michael, stops by to watch the boats get put in the water - we enlist his help in getting all the parts down to the beach.

Until now, neither of the boats has been fully assembled. There turn out to be lots of little issues - like how one of the paddle wheels hits the connector bamboo that holds the outrigger at the right distance.

Leo and Jacob collaborate on the paddle wheel setup.

Hanna and Theo tie the new decks on for the first time while Maxine talks smack about their catamaran.

Maxine trims off the excess on one of the bamboo cross bars.

The blade on one of the paddles is spinning due to a naive lashing attempt. Gever demonstrates the proper technique for securely attaching a stick to a board with line.

Isaac and Spencer have been chosen to take the catamaran out for it’s first sea-test - mostly because they are the lightest and there are some real concerns about how low the pontoons will sit in the water.

Maxine and Jacob literally drive circles around the catamaran - which sits dangerously low in the water, and whose innovative flap-drive doesn’t seem to work at all.

(that title is a play on the lyric “monsoon rain” - does that make sense or is it just so late at night that it seems clever to me? -ed)

The pontoons only have an inch or two above the waterline, and one of the tops is letting in a lot of water. The team will address this problem back at the studio by possibly adding another layer of canvas to the top.

Despite the fact that the crank didn’t get fully glued, and one of the paddlewheels had to be severely trimmed, the paddlewheel outrigger is surprisingly quick in the water. The catamaran team has decided to junk their flap-drive and build a paddle wheel for their boat too.

It is determined that the distances between the struts are too far for the strength of the canvas, so Spencer and Theo build styrofoam bulkheads to act as non-structural canvas supports.

Gabe is working on a foot-pedal steering mechanism for the outside team’s boat. It’s complicated because there is no floor in the boat yet.

As part of an ongoing theme, Jiro and Leo collaborate on this daily picture of “The Drill Master”.

The outdoor team has decided to use a beautiful pea-green for their outrigger. Turns out Maxine has a knack for applying wax.

To allow for changes to the rudder mounts on the catamaran, Theo must build plywood bulkheads to attach the canvas skin to (instead of the rudder mounts). It’s a tough drilling operation because round notches to accommodate the PVC tubes must be drilled out of each corner of a triangle, so he’s using clamps liberally. Leo is just hanging around the drill press to look cool.

Among the debris of boat construction, a beautiful wildflower has blossomed.

Spencer is striving for a perfect, wrinkle-free, wrapping of the last pontoon of the catamaran.

Theo hammers the new plywood bulkheads into place.

You know it’s a busy building day when all the major power-tools are on the deck before lunch. Maxine at the chop-saw, Theo at the drill-press, and Hanna on the jigsaw - Spencer waiting his turn.

Everyone agrees that Theo and Hanna manage to lay down the best wax job ever.

The sun comes out while Maxine and Gabe develop a hanging seat in the big outrigger. As you might imagine, it’s a bit tricky to put a seat in a boat with canvas sides.

The teams have mutually agreed that they all need paddles in case their propulsion systems fail. Maxine and Leo make a couple of paddle blades before going in search of suitable handles.

Spencer and Isaac take one of the waxed catamaran pods back to the studio for rudder work.

Note the piece of blue high-pressure gas pipe on the ground.

Everyone needs a break from boat building so we all go outside to see what fun can be had during the break in the fog. We spy the blue gas-pipe and note how well it slides on the pine needles…

Spencer grabs nine feet of it to make a stand-up sled.

Leo and Isaac discuss the relative merits of wood and pipe. Like skiers and snowboarders, they fail to understand each other.

Isaac shows us how it’s done west-bay style.

Maxine sprints down the hill with a wide-eyed Theo in tow. Hanna is more dignified than all that.

No handles, no brakes, no steering, and just too much fun. Theo zooms past as Maxine pours on the speed.

It’s the only thing anyone yells beside “whoa!” or “aaaahhhh!” on the downhill sled ride. Theo is not pulling as hard as Maxine did, so Leo is yelling “Faster, faster!”

Maxine, exhausted from pulling the sled, takes a little nap on the porch, nestled among the pliers, paddle wheels, lashing twine.

Spencer has invented a new toy which tickles your hand. Sure enough it elicits giggles from Maxine as well as everyone else daring enough to try it.

After his first prototype failed to pass inspection, Gabe digs in and starts work on a new design that is larger, simpler, and has more throw. Jacob helps him hold the stapler down.

The big outrigger requires a new technique for stretching the canvas skin tight, since passengers must be able to sit down inside the boat. A strong-line is run from bow to stern down both sides, then the pink canvas tensioning lines are tied to it, which creates some nice spiderwebby patterns inside the boat.

Tonight it’s chicken enchiladas, salad, and chips with guacamole - and of course, as much fruit as you can eat.