BikeGen, Stage 1: Measuring Output

After testing the current with the fuses last night, I figured there was no way I could possibly be producing more than 10 amps of output from the alternator with those resistors in place, so put my multimeter inline (ammeter mode) and started cranking.  I worked out for about a half hour keeping my heart rate at about the 85% level again.  Throughout that time I produced no less than 0.85A of current.  So in sum I was able to harness about 1/10th of what I should be able to produce, or about 0.425Ah.  At this rate it will take forever to recharge the car battery.  I was however able to charge my iPod while riding.  Producing enough juice to rock out was definitely cool, even if the amount of juice was tiny.

Next up, decreasing the resistance by adding more resistors in parallel.  RadioShack, here I come.  I totally love that RadioShack is also sponsoring Lance's team this year.  It makes buying parts for this project extra fitting.  I'll probably pick up a few more of these, which will get the total resistance down into the low 1Ω range and should also help to cool the dissipation of the heat (even thought he three that are on there now don't seem to get hot).  I also need a way to wire these up a little cleaner, I've got these resistors seriously kludged together right now.  Hopefully they will have some euro-style terminals at The Shack too.

BikeGen Stage 1: Is there an EE in the house?

I'm just gonna put it out there that I didn't do so hot in Physics at college.  I did get  B+ the second time around though...  In my flailing around, I ended up finding that placing resistors on my alternator output (rather than the field charging wire) would allow me to pedal with a low resistance level on the nearly dead battery.  I still haven't had a chance to charge it up full to try pedaling it at full charge.  In one attempt to find the proper level of resistance (Ω) to put on the line, I did burn up a rheostat, which was kind of cool in the setting-fire-to-electronics sort of way.  So what I've got right now is a set of three resistors, two 10Ω 10w and one 8Ω 20w all wired up in parallel on the alternator output line.  With this setup, I was able to ride for a full hour, keeping my heart rate at at about the 85% mark where I like it, and was able to increase the voltage measured at the battery during that time.  It went from 12.0v to 12.5v with no load other than the battery and the resistors, this of course started dropping as soon as I stopped pedaling because I really wasn't putting out that much juice so I was just affecting the surface charge.


Now back to those resistors.  I am a smart enough cookie to figure out that in parallel they make 3.0769Ω of resistance.  And I think they are capable of dissipating a combined total of 40w.  What I don't get at all is why in the hell that works to make the load easier.  I would have thought that increasing the resistance on the alternator output line would make it harder to pedal by causing a voltage drop that would be sensed by the alternator which would then try to work harder to make power.  But I guess this just demonstrates that there's something I definitely do not understand at work here.  I put the rheostat in the resistors' spot yesterday, that's when I burned it up, it could only handle 3w.  Burning electronic components smell really bad.  I think what I need is less resistance on the line.  With the rheostat I found by placing higher resistance on the line I could pedal easier, and with low resistance, there was a point where all of a sudden it was like hitting a brick wall.  So it seems a low ohm, resistor capable of dissipating something less than 40w is what I need, maybe.  I definitely don't know how to calculate what that is exactly.  I tried putting a small incandescent bulb inline to see what would happen, and the answer is absolutely nothing.  The bulb lights up and then the system never makes power.  So at the moment I'm stuck with my resistors.  Here's what it looks like now:

Just for kicks, I removed the resistors from the line, and replaced them with a 5a fuse, just to see if I was able to put more than 5a down that line.  The answer was definitely yes.  As soon as the alternator powered up, POP.  I replaced that with a 15a fuse which is more than I should be able to produce and it was, the 15a fuse remained intact.  If I had a 10a fuse I'd try that, cause if it worked, then I would be safe plugging my multimeter into the output wire to measure the current outflow.  Can't guarantee that yet though so I don't want to risk the meter.  Though I probably should wire some fuses into this thing...


So I'm kind of stuck, a little.  Another site I've come across says that that a 25Ω 25w rheostat on the field charging line will work, this I am skeptical of because the 25Ω 3w rheostat I tried didn't do anything at all, it was like it wasn't even there.  I'm more wondering what a smaller Ω rheostat with that higher wattage would do on the alt output line side.  Another diagram I found shows a fixed 0.47Ω 25w resistor on the alt output with a switch enabling a second one in parallel.  This is more along the lines of what I am wanting to try.  I would definitely appreciate some help in making sense of why the resistors seem to work where they do.

Stage 1: Tweaking

By "tweak", what I really mean is flail around trying random crap I find on the Intarwebz till something works.  The resistance problems I've got are so far pretty significant.  By resistance, I don't mean electrical resistance measured in Ohms (though I've been learning about those too), but rather how hard it is to turn the alternator when the field is powered up.  To which the answer is very.  I actually slightly strained a hamstring trying to crank it over once the field juices up and starts making power.

A friend of mine from college suggested that I may not have a functioning diode in the alternator, which made sense to me, but I was able to disprove that using the diode test mode in my multimeter.  My next idea was that the load being drawn by the battery is very high due to the battery being mostly discharged.  The voltage in my Battery is so low that it's was basically flat.  Connecting it to my car's battery in parallel to charge it up got me up to around 75% charge.  The load is still too great to sustain pedaling.  This is a major problem since part of this idea is that I would be able to at least partially discharge the battery and recharge it.  If this theory is correct, I would only be able to draw as much as I could put out instantaneously, since recharging the battery grinds me to a halt.  So I need a way to limit the load.

I found some kids at MIT that tried to use an Alt driven by bike wheel deriving the cranking power from a Ghatta, which is a type of water driven millstone in Nepal.  They found they needed to modify the field current with resistors in parallel to bring the current to the Alt field down.  That didn't seem to do anything useful with the resistors I tried.  These guys also made me realize I'd been driving my alternator backwards...  I fixed that, and still no love (and I hope that didn't mess any of the internals up).  Then I found some Brits that say you put the resistors on the Alt output line to bring down the load, though I have to admit, I don't see how that would do it at all.  But that's my next try.  Also, I will attempt to further charge my battery up to full to see if a full battery lightens the load.

Stage 1: First Serious Test

Well, I've already broken some guidelines. I did pay $0 for the alternator and the battery, that's a major component of the expense of this project. But in order to drive the thing, I needed a belt, a long belt. It had to be up in the neighborhood of 83" and be able to fit in the skinny little pulleys that were stock on the alternator. Getting a free belt didn't seem very likely to me so I decided to just choke down the cost. After describing what I needed to the dudes at Pep Boys, then explaining what I was building out of the alternator, and how I was not actually crazy (not sure if they bought that one from the looks I got), they helpfully sent me to Napa, where you can get get belts for ride-on lawn mowers and other machinery type equipment. The guy at Napa was very apologetic that they didn't have an 83" belt in stock, and hesitantly offered me an 84" belt, I told him that the precision of the length was not that important since the machine it was for, hadn't been designed yet! The $25 cost was actually covered by some earmarked cash I got for Christmas. The expensive part was the wiring bits and bobs I got at Pep Boys. I got a few rolls of 10g and 14g wire ($5 a piece), a couple switches ($4 a piece), some marine battery clamp terminals ($4) and several boxes of wire terminals in various sizes and gauges. This added up pretty quick. I will only actually use a fraction of the wire and terminals, but if I was going to wire cleanly and for the long term, I needed to source these. So oddly enough, I spent more on wiring parts than I did on the Battery ($0), Alternator ($0), and Belt ($25), combined. The devil is in the details, as it were.

Next came the base. I needed to firmly mount the alternator on a tensionable hinge. Using a couple small piece of scrap plywood and a scrap 2x4, I came up with a mount that would butt up against my existing stationary trainer, would use the weight of the battery to keep it down, and a turnbuckle to keep tension on the belt. Luckily my alternator has an integrated mount designed to be a hinge for tensioning, so this was actually pretty easy. I first tried to use just the weight of the alternator to keep tension, but quickly found that this was no good.

It resulted in voltage spikes and drops as well as extremely uneven resistance at the pedals in some preliminary testing. The addition of the turnbuckle was key.

So with the base unit pretty much in place, I wired everything up. I used the wiring diagram from P2cycles.com as a guide to put all the connections in place, my thanks to them for providing such a clear diagram. Hopefully, I will eventually have all of the trick connections in place down the line to measure power and have the bar mounted switches as they did in their very sexy implementation.

Then it was time for a test. As an afterthought, I wired up some leads that would allow me to more easily read the multimeter while pedaling, and also hooked up some leads to an inverter, to which I plugged in my iPod. The iPod's battery was completely flat, as a bonus.

Here's the test:

It's a go! I was able to get voltages up around 14.4v while pedaling. What you don't see in the video is my heart rate, which I do have a readout on my handlebars for. Unfortunately, my pulse quickly hit 180, which is basically my max output. I was only able to sustain a cadence >90rpm for about 5 min, and I was completely juiced at the end. I think this is the result of the car battery being almost completely flat, I initially charged it just enough to be able to power the alternator's field. I think the voltage sensor in the alternator is detecting that the battery is low, and putting a heavy field in place to charge up the battery. I'm not sure about this and I need to do a little more research. While I look into it, I'm going to charge the battery up to a higher level, just in case.

New Project: Bike Powered Generator

So here's my new 4 stage project: Take some bike parts and some car parts, and put them together to make some electricity. This is not a new idea. It's not even that original. Pretty much everything I aim to do, has been attempted and done before, just not by me. Hopefully, Stage 4 will be where it really opens up into new territory, if I make it that far. Jim and I have been talking about doing this for somewhere close to 2 years now. In that time, a lot of the things we've talked about have been done by other people. Each time we come back to the topic, we learn a little more and it gets a little closer to reality. This time the topic came up, something sparked in my brain and it's time to execute on it. I have come up with some basic guidelines to take me forward:

1. Spend $0 on new bike-specific parts. My bin runneth over already.
2. Spend as little as possible on the electrical parts.
3. Stage 1 must be completed before messing around in Stage 2, and so on.
4. Power must be usable, to get out of Stage 1, the system will have to measurably produce full power for an hour of riding.

I should probably outline what I'm hoping to accomplish before I get too far down the line. Stage 1: Working stationary bike that is capable of producing usable 12v electricity and storing it in a battery. Looking to create a sustained 80w of power at this point. Hopefully 100w, but we'll have to see how efficient of an alternator I can get for cheap. This will require some parts and materials some of which I have, so I will have to scrounge:

• 12v DC alternator
• 12v deep cycle battery
• Wiring in various gauges and terminals to connect them
• Drive belt
• Nuts/bolts and some parts to mount this up to my stationary trainer
• Ammeter to quantify the output

A few days ago, I pulled an alternator and battery from a junk 1988 Dodge Caravan that my dad had sitting in the farm yard. It's a 3 wire, 75 amp aftermarket alternator for that van, so I'm hoping it's good and efficient. The battery is not a deep cycle battery, but it was also an upgrade for the van, a Die Hard that will do 800 cold crank amps. Eventually, I'll need to swap the battery for a deep cycle version so it can take repeated charges and discharges. Last night, once I figured out what the heck the wires were all for, I hooked it up in about 15 minutes, with some seriously half-assed connections.

My brother-in-law Jared helped me hold the alternator pulley against the rear tire on my trainer while I pedaled. I had a multimeter set up to show voltage. While powering the alternator field without movement, the volts were down just above 2v (battery had been sitting for a long time unused), I started pedaling, got it up over the 1800rpm range, and the voltage spiked up to a full 14.4v which means the alternator was then successfully powering itself and beginning to charge the battery. So with Stage 1 solidly underway, now comes the more serious business of cleaning up the wiring and mounting the alternator solidly to produce a constant level of power output. So here we go.

Snow biking

Today was a great day for a ride. The first somewhat serious snow of the year, where the snow actually sticks to the ground. Riding a trainer indoors lets you pedal when it's cold and dark, but it's never the same as getting a good ride outside, in fresh air. This is the time of the year when riding after work basically means riding in the pitch black so I'm not big on it.

It was a bout 30°F, I set out on the trails I grew up riding on the high tension powerlines down the road. Those trails have gotten really bad over the years. Many sections are impassable because they are submerged in too much water and mud to pedal through and are lined with thick bushes. I did find some promising new trails though. The snowmobile/atv trail network crosses those powerlines and so I hopped onto them. Never having explored those trails I wasn't really sure what I was in for but they ended up being really nice riding.

I'm not sure exactly how far I went, but I am guessing about 12 miles. On the mechanical end of things, these linear pull brakes have got to go. They got so caked full of crap that I had to stop and unpack the snow and leaves from them quite often or the drag would be unreal. I have a set of Hayes 9 Carbon discs in a box waiting to be installed. I'm waiting for some IS to post mount adaptors to come in to mount them up.
A number of places provided for some interesting riding, in this place the trail had been long since washed out and there was a long technical descent down what had evolved into a streambed. I saw a huge flock of turkeys at on point, they didn't quite know what to make of me. Eventually I came out onto another smaller powerline and I thought I was heading in a different direction than I actually was. I thought I was on a trail I had never been on before, but it turns out that I was actually on a trail that I had been on several times, the snow just made it look different. Granted, it was also about 15 years ago the last time I was there. It was a great ride today, made me feel pretty good. Hopefully the ground will freeze up a bit more without lots of snow falling here quite yet so I can get out on the trails here a few more times before winter really settles in.

New Bike, New Turf

N+1=10! WOO!

I finished the build of my new Redline Monocog 29er. Cane Creek 110 headset, Hope Pro 2 hubs, WTB Dual Duty rims, Panaracer Rampage 2.35" tires, Sette Venn seatpost, Jamis Stem, Easton EA70 Monkeybar, Ritchey True Grips, Bontrager Race saddle.



I took said bike on a ride:





Needless to say, it was a pretty long ride for a single speed. The trails I found were smooth and fast, so the relatively tall gear (32x18) I have on it right now is OK. Didn't really get the bike dirty. The trail entwork I got into is aparently quite extensive. I met a guy out in the middle of it that told me if this was my first time out there, not to get lost cause it is big. So I explored lightly and am looking forward to going back again. Looks like there's a good bit of single track available out there in addition to a bunch of double track with some fun little whoopty-doos.

So that was last weekend. This weekend, I revisited the powerline trails I grew up mountain biking on. I haven't been on them for probably a good ten years now. They've changed a bit, some parts were moved, some parts washed out, some permanently flooded. The 32x18 drive is too tall for this area. I have a 20t on order to try out. Some parts of teh trails are very technical. But on the whole the present state of the trails could be described as "muddy."

After:


I learned a few things about the bike:

1. It will roll over just about anything.
2. The tires, though reviewing well for mud, well, not so much.
3. I need to lower the gear ratio.
4. I want to try lock on grips.
5. The brakes I have suck in mud.

Tomorrow, hopefully riding some trails I've never been on with some buddies. Oh yeah, I turned 30 on Friday, woo.