Tighten those spokes!

We finished crimping in the spokes for our wheels.  Over 196 spokes to make and then mount into the 4 wheels.  Luckily we won’t have to do that again.

We bought an old golf cart that we hope to use for steering and suspension parts.  I threw all of the plastic away and removed the unnecessary metal until I had it down to just a bare tube frame with wheels.  Golf carts have a very similar wheel bolt hole pattern as our older model Prius wheels.  Prius wheels are 4 x 100mm and golf carts are 4 x 4″ (101.6mm).  That slight difference isn’t enough cause us a problem at our low speeds.  I didn’t plan this out originally, but I’m not going to look a gift horse in the mouth!  Now we can use golf cart parts on our art bike!

We used the rear hubs of the golf cart to mount the wheels for our spoke tightening/truing.  We could spin the wheel and eyeball the alignment to make sure we’re keeping the outer rim concentric to the hub.  Aaron and Tyler tightened all of our spokes down and the wheels are suddenly very strong and impressive.  They even bounce a little bit, as if they’re pneumatic.

Don't they look purty!

The result is 4 beautiful wheels.

So far I’m about $600 into the project.  The plastic culverts were donated, as were the damaged prius wheels.  I got the golf cart and a riding lawnmower transmission for a little over $200.  The rest of the money went towards crimp stoppers, thimbles, aircraft cable and eye-bolts.   So far so good.

The next thing I’m focusing on is designing the drivetrain.  There are many considerations to worry about: cost, weight, ergonomics, how to install/maintain, robustness, and sourcing of components.  I’ve been talking to Scotty C and another fellow he introduced me to online.  They’ve got some great ideas, and I suddenly think this is actually possible!

From mowing lawns to gourmet meals, what a life it's lead!

The riding lawnmower transmission that we’re going to try to utilize is an interesting piece of hardware.  We opened it up to see how things looked inside.  Everything seemed functioning and well lubricated.  I think it will work just fine.  Inside of the transmission are 5 forward gears and a reverse.  I wish I had taken a picture of the innards of the transmission, but my hands were filthy with grease and I didn’t want to grab my camera.  The output is through a differential, so this will make turning the banquet table much easier.  The shafts are 3/4″ and it’s got tons of places to bolt it in.  The whole contraption weighs about 25 lbs.  I only need to count the revolutions of the shafts to determine the gear ratios.  The part has a number on it, but a search for Spicer 4360-68 didn’t arrive any any good technical information.  Spicer apparently doesn’t let DIYers working on their transmissions.  I’ll show them!

Spoke Assembly Line

Crimping Ain't Easy

It's important to keep the workers well fed.

Kind of like flower arranging, except with metal.

Our first completely spoked wheel, ready for tread.

These old bike tires will get a second life.

First wheel is finished!

We’ve got 3 more wheels that need their tire tread, and two more need to have their spokes run.  But, we finished a lot of the arduous assembly line work.  Now we need to finalize our design and start ordering some steel for the frame.  Thanks for all the help guys!

Finally I can stop paying for all of my ZEV parking

Back when I was researching all of the perks of owning my own electric vehicle, I came across a decal that is given out by the California DMV.  It is intended to assure that the vehicle that’s taking up the “EV only” parking/charging spot is actually an electric vehicle.  I thought that I might as well get the decal, just to be on the safe side.  After $17, one sheet of paperwork, and a couple of weeks, my decal arrived in the mail.  I must say I was underwhelmed.  It looks more like a kid’s sticker than an official designation.

There are two things that I would like to discuss.  One is that I am apparently the 662nd EV to get this decal in CA.  I keep waffling back and forth between this being a lot, or a little.  I’m curious what the number will be after the Leaf, Volt, Circuit and the other EVs hit the road.  Will people even bother getting this decal?  I suppose time will tell.

The second thing I want to discuss is more of a rant about public policy.  It’s basically how EVs and hybrids get lumped together into incentive based legislation.  Let me start with an example.  In an effort to get people to adopt more fuel efficient vehicles and such in LA, the city made parking free at every parking meter for EVs and hybrids.  Amidst all of the recent budget problems the city decided to rescind that privilege.  I wonder how many EV owners there are in LA vs hybrid owners.  In reality, hybrid fuel efficiency is only 10% better than old, small engine vehicles such as the Geo Metro and much worse than new diesels that will be out on the market soon.  EVs, on the other hand offer a much greater increase in effective MPG than the hybrids, or other combustion based vehicles.  A typical value for EVs is 250Wh/mile.  Which if you convert to what that would be in gasoline it relates to a 144MPG.  If the goals of the city involve cleaner air, then EVs should be given a greater incentive than comparably lack-luster and dirty hybrids.  I don’t think it’s maximally effective to incentivize technologies that are only a marginal improvement.  But of course, I’m highly biased.

**UPDATE***

And it never mattered anyway.

I recently got this letter in the mail.  (Click to see a semi-readable version.)  Recently there was a change of California laws.  The DMV is stating that I no longer need my ZEV sticker to park at an EV-only parking spot.  To confess, I never actually put it on anyway, so this doesn’t really effect me.  But, it goes on that I have to actually be plugged in to the charger or I risk being towed.

At first this seems like a reasonable law.  If I’m not charging, I shouldn’t hog the charging parking spot.  Fair enough.  But, it’s common for EVs to share.  I can plug in, but leave a note saying that it’s okay to unplug me after, say, an hour.  Someone else drives up and unplugs me to plug themselves in, and everyone is happy.  At least that’s how it used to be.  Now I might be towed if someone else comes along and thinks that I’m just hogging the space, when actuality I was just sharing the juice.  The law was written at the behest of GM lobbyists, who are pushing to get their Plug-In Series Hybrids into the EV spots.  But, the vagueness of the law is such that it doesn’t say that I need to actually be charging a battery pack to park in an EV spot.  I could run an extension cord out of the trunk and charge up an electric razor and qualify.  It’s a poorly worded law, and I hope these negative things don’t come to pass.  Time will tell.

I frequently park my car at the Santa Monica Civic Center.  The city of Santa Monica has a fleet of EVs and Compressed Natural Gas vehicles, which they use for running around town, doing whatever city bureaucrats do.   I’m usually the only non-city owned vehicle in those spots.  I can’t help but notice that the EVs are never plugged in, and the CNG cars can’t even plug in.  Almost the entire Santa Monica green fleet is in violation of the CA laws!  It hasn’t been a problem, as I have always been able find a spot for myself.  But, now I have options!

A glimpse into the future!

I just launched our KickStarter campaign for A Moveable Feast.

http://www.kickstarter.com/projects/480257067/a-moveable-feast

Check it out and help out if you can!  Thanks!

One of the boxcutters used to hijack one of the 9-11 planes.

At face value the security checkpoint at an airport has a goal of preventing people from bringing weapons on board flights.  It makes sense that I don’t want a crazy guy with a gun on the plane.  But, even the smallest of weapons have made a big impact.  The 9-11 hijackers famously used boxcutters to keep any vigilantes at bay.  As a result, the TSA decided to confiscate everything from pocket knives to sewing scissors from carry-on bags.  Makes sense right?

Now, let’s say someone wanted to bring a weapon on board a plane nowadays.  You’d think it be pretty hard to do so, what with all of the security we’ve got.  But it is possible to waltz through security in your underwear and simply construct a deadly weapon from items purchased in the Duty-Free stores.  Here are a couple of examples I could think of while I most recently traveled.

More dangerous than any box cutter.

Purchase a cheap bottle of wine or other hard alcohol.  Break the glass when you’re ready for use.  A broken wine bottle is much more dangerous than an 8″ long screwdriver.  And they let you carry it on the plane.  While you’re there, buy a few bottles of perfume.  Their high alcohol content will make for a great flammable bomb.  I’m sure you could google how to make molotov cocktail out of that.  You can light it with a non-banned lighter or pack of matches.  At least it will smell great before the cabin is consumed in fire.

Our security is only as good as the weakest link in our armor.  And yet we’re extremely happy to sell dangerous weapons to anyone who wants them AFTER they’ve been cleared through security.

My point to all of this isn’t to argue that our security needs to be tighter.  I’m just pointing out that our security isn’t tight at all, and that’s not a problem.  People don’t need to have their small knives and tools taken away from them.  They don’t need to remove their shoes.  They don’t need to be doused in radiation to look for smuggled weapons.  A lack of weapons isn’t what’s preventing terrorism occurrences in our country.  The TSA is merely wasting our time and our money on expensive gadgets and overstaffed security lines.

Just doing her job.

The TSA is in such a fear based mentality that they are making traveling very unpleasant and difficult.  People have to arrive very early at the airport or risk missing their flight only because of long security lines.  I believe that this has a very real and damaging impact on our economy.  It’s simply harder to get around the country.  In summing up, I’ll leave you with this.  The TSA is so paranoid that it includes this question in their FAQ: “Q. Why is breast milk not a threat?“  I implore you, who the hell is frequently asking that question?

Recently I found a bank that actually drew my attention and got me thinking about actually acting: New Resource Bank.  The bank purports to invest in sustainability programs, both big and small.  It even offers “Solar CDs” for investment.  (I’ve determined I can get a much higher ROI by putting up my own solar panels, but I like the thought.)  I only need it for online transactions, so the fact that it’s in San Francisco doesn’t slow me down one bit.  I set up an account and I’m in the process of transferring my banking over to the more sustainable option.

It’s hard to argue with “voting with your money”.  And it feels good to no longer support the big banks that I feel do so much harm to the planet and economy.

***UPDATE***

I unfortunately have to rescind my support of New Resource Bank.  I was just about to get into the swing of using their bank, when I had problems transferring money into the account.  They apparently have a limit on how much money I can transfer into the account, and it’s so low that I can’t utilize it for online banking.  None of my previous accounts had this low limit, so I was surprised.  I called and talked to the customer service, and they couldn’t raise the limit high enough for me.  I’m really not sure why.  It’s very frustrating, as it’s clearly an arbitrary limit that they’ve imposed.  So, I’m closing my account.  If you have a progressive bank that does work, please let me know!

I had the priviledge of pedaling this beauty for a very short distance. What a joy!

For the past 4 years, I’ve been jealous of the kinetic sculptures at Burning Man.  Duane Flatmo’s beautiful creations were the first to catch my eye.  But soon I was noticing many other art bikes on the playa.  I kept dreaming about building my own, but I couldn’t wrap my mind around how to get started.  This past year I made an effort to walk around and meet some kinetic sculpture artists and find out how they built theirs.  I looked at their drivetrains, suspensions, and wheels.  There are so many aspects to think about in the design, but one has to start somewhere.

Brent's sketchup wizardy brings ideas closer to reality.

The first thing I needed was the art concept for mine.  I mulled it over in the back of my mind for a few months.  Finally I arrived at what I think is a winner: a banquet table art bike.  The idea is that 8 people can sit around a large banquet table that is covered in a delicious feast: fruits, meats, cheese, goblets of beer and wine.  The participants are naturally pedaling furiously under the table to propel the thing around the playa.  During the day it could double as a mobile mad hatter’s tea party.  I described my idea to Syyner Brent Houston and he whipped up a fantastic rendering for me.

Plastic culverts are the wheel material of choice. Light and strong.

Now it’s time to get started.  I found a fantastic resource in Scotty C’s website.  He gives a thorough explanation of how to build art bike wheels.  I had met him at Burning Man and got his contact information.  He even gave me a huge head start and delivered a chunk of 36′ diameter plastic culvert.  Enough to cut up and make 7 wheels!  That’ll give me enough for 4 wheels for my Banquet Bike and 3 more wheels for some sort of tricycle at some point in the future.  Thanks so much, Scotty!

In describing this idea to my friends, I amassed a small group to help design and build the art bike.  It’s much easier to build these things with some support from eager workers.  Aaron Davis managed to salvage some aluminum car wheels (I think from a Toyota Prius) from some sort of junk yard.  The wheels had bends in the rim so they wouldn’t hold air, and hence were useless for cars.  But they will make nice and light hubs for our wheels.

I determined that our wheels should have 48 spokes each.  They’ll have crossed patterns, so they can deal with the torque of pedaling.  The front steering wheels technically don’t need such torque support, but it was easier to make my wheels uniform.  I crunched some numbers to determine the length of the spokes and the hole spacing I’d need in the inner and outer wheels.

First we measured out the hole spacing in the aluminum wheels and punched them to keep the drill bit from walking.

I organized a work party to get started.  We drew out our spacing on some tape and wrapped it around the aluminum wheels.  It was straight forward to mark the wheel and give it a sharp rap with the punch.

Luckily aluminum is nice and soft.

Then it was a matter of drilling out all of the holes.  48 x 4 is 192 holes in the aluminum wheels.  Of course, there is that many in the plastic as well.  It goes a lot faster with multiple people taking turns and working in parallel.

Holden and Meagan make short work of the ABS spoke holes.

We then needed to repeat the process on the plastic culvert wheels.  The spokes will go right between the corrugations.  Washers will keep the spokes from pulling through.  The plastic was much faster to drill, but it’s still a lot of holes.

For a little extra strength.

The next step was to start on the spokes.  They’ll consist of 1/16″ aircraft cable with stopper ferrules on the end to keep it in the aluminum wheel.  On the other end the cable will connect to eyebolts that will go through the plastic. We’ll be able to tighten the nylok nuts on the eyebolts to tighten the spokes as needed.  I figured that we might as well weld the eyebolts all the way closed just in case they bend open up a bit over time and result in loosened spokes.

Lots of little parts to make the spokes.

We then started crimping together our spokes.  We have 192 spokes to make, but you have to start with one at a time.  It helps to have someone squeeze the crimper while the other person holds everything in the right place.   By this time we were a little exhausted and felt that we had made some great progress.  But, we just had to assemble a proto-wheel with our first 16 completed spokes.  This was also a good test of my math to determine the spoke length.  We didn’t tighten anything down yet, but it definitely felt good to see the first wheel start to come together.

16 of 48 spokes. Well on our way!

One hole drilled for a pipe thread, the other for a 1/4" OD tube.

Step 6.  Prepare the plate for the propane side.  I drilled and tapped a 3/8″ NPT for the brass fitting.  The other smaller hole is for a tube which I’m welding in for an attempt at a pilot light.  If you’re building your first tube, you can ignore this, as it may not work well.

Welded and plumbed

Step 7.  Weld the plate into place.  I also had to weld my pilot tube through the plate and out through the top of the tube, so it as a bit of juggling.  I then plumbed it with a brass flare fitting that mates with my propane hose.  The plate isn’t very thick so it’s easy to strip out the few threads of pipe thread.  Always use two wrenches to tighten/loosen the flare fittings to prevent over-torquing these relatively delicate threads.  A better solution might be to braze or silver solder the flare fitting to the steel plate.

Cutting the rubber is as straightforward as it gets.

Step 8. Seal the speaker side of the tube.  I use a thin rubber that is rated for exposure to propane (caution, not all rubbers are equal!).  The rubber I found is Buna-N rubber that I got from McMaster Carr.  It comes in a big sheet and I’ve been using the same one for all of my tubes.  I poked the screw holes through the rubber so this plate can hold the rubber sheet against the flange that is welded onto the tube.  The speaker is then installed over the whole package.  The speaker never touches the propane.  The frequencies can easily transmit through this thin rubber.

Fire at last!

Step 9.  Fire it up!  After sealing the flanged end with rubber, I was ready for a test.  The tube may take a while to fill with propane (which is heavier than air), but eventually you can light the flames.  I adjust the pressure on the propane bottle with a regulator to get a nice small, even flame across the entire tube.  It’s then easy to see if you have slightly clogged holes.  I usually just use a drill bit by hand to clean out clogged holes.  The result speaks for itself.

I hope you enjoyed these instructions.  If you have any questions, don’t hesitate to ask in the comments down below.

The first thing I noticed is that there are way too many types of cells.  I’m not going to worry about them just yet.  The first thing I need to figure out is how big my system is going to be.   I’m not wealthy, nor do I have a lot of space in the backyard, so I was thinking of starting with 500W or so.    But, since I plan on expanding my solar output in the future as I have more space and money, I figured I needed a modular solution.

A friend suggested I look into Enphase micro-inverters.  They provide inverters that connect to each individual panel.  This has three benefits for my application.  They provide high efficiency as they optimize for power on the current/voltage curve.  They claim 96%!  They allow for easy upgrades, as each new panel will get it’s own micro-inverter.   Everything just plugs together.  I don’t have to utilize only half of a 2kW inverter while I save up for more panels in the future.  Finally they feature an online service that lets me track the power output panel by panel.  This will allow me to effectively bill my roommates for the electricity these panels produce.  Otherwise, it’d be very difficult to recoup their cost.

I still need to figure out how I’m going to wire things up, but I think I have my strategy mostly figured out.  I’m putting up a few panels now as my location and bank account allow, but leaving room for my system to grow in the future.

I had quite a few reasons to not even bother looking into solar panels.  One of the big barriers was the fact that I rent.  I don’t own a roof to put solar panels on!  As such, I’m not eligible for any government rebates.  I’m certainly not philanthropic enough to install thousands of dollars on someone else’s property.  Besides, my landlord would probably nix the idea anyway, citing a perceived bad aesthetic in our prestigious San Marino neighborhood.  I don’t have the $12K for a large system to cover our electrical needs, either.

But, I decided to look into things anyway.  Maybe there’s a way that I can put up a smaller modular system without breaking the bank.  Maybe I could mount it on a stand-alone fixture in the backyard and avoid the roof and the landlord altogether.  But, how much will it cost, and what will be my return on investment?

First let’s take a look at what we’re paying for electricity right now.  We’re on a time of use plan with Southern California Edison.  Each month we always cross the tier 1 threshold for our house, and pay expensive fees for tier 2 electricity.  During the winter, electricity during peak hours costs us 26¢/kWh.  But, during the summer season we pay a whopping 54¢/kWh between the hours of 9am to 6pm on weekdays.  We try to cut back our usage as much as we can during this part of the day, but we can’t do too much about refrigerators and the like.  Luckily those expensive hours of the day are exactly the times that the solar panels would be operating.

So, during the summer pay season (March – October?) our solar panels will be offsetting 54¢/kWh.  That means they’ll be able to pay for themselves relatively faster.  Using a rule of thumb of $4/Watt, the solar panels will pay for themselves in less than 2000 hours of full sun.  Not bad at all.  After that it will be generating money, for the rest of their lifetime.  Electricity isn’t likely getting any cheaper, so I’m sure these panels will only get more lucrative.

I’m a firm believer that green solutions can be better for the wallet as well as the planet.  Solar panels are a great example of that.  These panels will pay for themselves in about 7-8 years.  Without any tax rebates, they are delivering a 12-15% return on investment.  That’s a great investment in my book.

In the next post, I’ll detail some of the actual equipment that I’m looking into.  I’ve got to be realistic about size, placement, and how I’m going to safely wire things up.