[Amberwolf]

Now, this won't be a complete build thread, since I started the project a while before I found this site. Instead, I'll refer you to my original project blog at http://electricle.blogspot.com for the older stuff, and give highlights here for new things from here on out, with links to the relevant posts on the blog.

First up is a description of the thing, which is viewable in an older form on EVAlbum, at http://evalbum.com/2691

It's made from a couple of bicycle frames; one a 20" Magna kids bike, and the other a 26" (maybe 700C or 27", not sure) Schwinn 10-speed adult bike. Had to do this to make it long enough to put the seat back a ways without being over the rear wheel, and still be able to keep the low-mounted crankshaft/pedals so I'm not sitting feet-up-forward, but rather am sitting more like in a relaxed lawn-chair sort of position.

The seat looks like a lawn chair, but is made from a bedside potty's frame rewelded into a useful shape and covered in a mesh laced tightly across it for extra suspension.

There is a front shock fork from a 24" Roadmaster bike, but no rear suspension, except for the seat. That alone is sufficient for most situations, and gives a much better ride than even the saddle with shock-absorbing spring-loaded seatpost on my Columbia upright road-bike.

Handlebars are downturned for better comfort, but are cruiser-style bars from some old postal Schwinn bike (from the 60s, I think, possibly very early 70s). On them I have a rearview mirror on the left side, a PDA running VeloAce for my speedometer/etc, and the usual brake handles, shifters, etc.

There is a dual-stage chain drive, with a complete regular rear bike drivetrain on the Schwinn frame (14 speed now, intended to be 21 speed if I can find another triple-chainring for the front). That rear drivetrain is on the right side as usual, with front and rear derailers. There are no pedals on the front end of that drivetrain, though, and instead the power input is on the left side of that crankshaft.

On the left side, there is a triple chainring minus pedal and crank that receives the chains from both the actual pedal chainring (on the Magna's bottom bracket) and the motor's chainring (mounted between and behind/below the pedals, where the rear wheel would be on the Magna).

The 24-tooth chainring (granny ring) of the left triple receives the power from the 24-tooth chainring bolted to the former wheel-mount on the powerchair motor's gearbox, which gives about 120RPM at max speed. That's faster than I'd prefer (90-100RPM) but I didn't have a smaller chainring that would fit on the motor's wheelmount without seriously modifying that mount. The motor itself is from a powerchair, with it's gearbox being designed to directly drive a small (10"?) wheel on one side of the powerchair, with an identical mirrored setup on the other side of the chair. I'm guessing it's around a 350W motor, but there are no specs on it (it's from Invacare) other than it's no-load speed (120RPM) and voltage (24VDC) and current (3.6A).

The 44-tooth (high gear) chainring of the left triple recieves the powre from the 44-tooth single chainring of the pedal cranks. There's no freewheel on either motor or pedals, so if I pedal I am driving the motor, and if I run the motor I drive the pedals, but I had no way to integrate freewheels into this design with the parts I had laying around. I did have freewheels on a prior version, which would have been driven by a treadmill motor, but that wasn't adaptable to this new motor setup, and wasn't capable of handling the power I needed it to, anyway.

So right now, if I am at full throttle, I'm pedalling like mad to "keep up" with the speed the motor runs the pedals at. Since I had a fault with the original controller that caused it to jump from around 2/3 power to full power, regardless of throttle type or input, with only about a hundredth of a volt change in input, it was pretty annoying. I almost always needed just a little more power than I could get without going above 2/3, so I'd have to run in full power for a bit, then throttle back, and so on.

The throttle right now is just a potentiometer with a leverish knob and spring return, mounted near the right handlebar grip. What it will be as soon as I have time to build the hardware is a hall effect sensor on a spring-loaded arm that is near a magnet on the frame (or vice-versa), with a roller on the end of the arm resting on the top of the pedal chain. As I pedal harder, the arm is forced upward, and the sensor setup to give more motor power the more upward it is moved. So the harder I have to pedal, the more motor power is applied. As the motor power increases, I can pedal less, which decreases the motor power. A balance is quickly reached, and thus I basically have a power-assisted pedalling that should feel about like what I would normally pedal like, except that I will never have to pedal the full mass of the bike (with my bad knees getting worse every year, I need this). Much easier to use than a hand throttle. For certain situations, I will also have the cable-style throttle twistgrip from a Honda scooter, whose cable will be setup to pull the throttle arm upward just as if I was pedalling (even if I am not), to give me a hand-controlled throttle as well.

It's powered by a pair of MK-Powered 12V 31Ah gel-cell SLAs, one on each side in my cargo pods (eventually to be moved to battery boxes under the seat on each side once I get the hangers made for them). They came from a powerchair (dunno if it was the same one). I recharge them with the charger that also was originally used on a powerchair, and it takes a few hours if I run them down to "dead" on the battery meter. That meter is also from a powerchair, with it's redline at about 18V.

I get around 15 miles range on a one-way trip if I run them down to redline, at my typical speed of 16-17MPH, which includes some pedalling, and lots of starts and stops in traffic. If I am on a long canal path with no traffic stops, I can get a few more miles out of that, because they don't have to provide the large current surges needed to get the bike moving. I also get longer range if I let them rest halfway thru the trip for an hour or two, with the best recorded trip like that being 22 miles or so. The fastest it goes so far has been 22.3MPH on a canal path test run (there is video on one of my blog posts).

I have complete lighting on the bike, from *very* visible headlights (CCFL slide/transparency adapters from computer image scanners), to LED marker lights, taillight, and brake lights, to some turn signals (front/rear) off an old Honda scooter. Those turn signals currently use incandescent automotive lamps, but are being converted to LED as soon as I finish wiring the boards up (which will include a RomanBlack power converter to take my traction battery pack power down to 12V to run the lighting).

I also have a car horn off an 85 Ford LTD, which has been useful more than a few times in certain situations, to alert people that somehow missed seeing me to my presence, preventing an accident each time.

I prefer riding it at night, both because it is cooler and because the lighting on it makes me more visible then than in daytime. Plus, people respect my place on the road more at night than in daytime, and don't nearly brush my left side like daytime drivers often do (no matter how far right I stay).

More to come.

[Amberwolf]

Now that the startup post is out of the way, I wanted to post that I finally finished my new controller to replace the old worn-out and way-too-often-repaired ex-scoot-n-go controller.

It's a 2QD, from http://4qd.co.uk , but built using only their PCB--all the parts are pulled from recycled junk I had laying around.

Blog post with full details
http://electricle.blogspot.com/2009/...by-solder.html

Basically I was on pedal-power only for the last 2+ months, as the controller died for the last time just as I had gotten a new motor to test on the bike (but had not yet connected it). Now I am finally going to be able to ride it as it was designed, without the problems the old controller gave me.

I also have a few major drivetrain mods to make:

The throttle system will change in the next few weeks, to the one described in the first post.

The chainrings on things will change. I'll be swapping the 2-ring set on the right with the 3-ring set on the left, using narrower chain (which I didn't have before) and larger ring on the motor end, and smaller ring on the pedal end. The effect of that should let me pedal a lot slower for the same power output, and not have to windmill my feet to keep up with the motor's max power. It will also give my my grannyring back on the rear drivetrain, which the lack of has kept me from having any hill-climbing power at all unless I was already going nearly full speed.

The bike (with motor and batteries) is about 120 pounds, so you can imagine trying to get that up any hills even with a small motor assist, along with my own 150 pound weight, plus the arond 10-20 pounds of stuff (water, tools, etc) I carry wherever I go. Even worse if the cargo pods are full of things like groceries and whatnot--can be difficult to even get up a driveway if i have to slow way down or stop first!

[Amberwolf]

I finally got time to redo enough things on the bike to allow me to put the brake/stud chain-tensioner borrowed from AussieJester at the FreakBikeNation forums on it.

There's pics and descriptions and stuff over at this post on my Electricle blog:
http://electricle.blogspot.com/2009/...ontrolled.html
I have not yet welded the stud to the frame, as I'm doing some testing and position-checking so that the magnetic/hall-sensor tension-controlled throttle will work properly, so it's only tacked in position and clamped in place with a radiator hose clamp. But this is basically it:
http://3.bp.blogspot.com/_zHr5qzOZQ9...ideCloseup.JPG
http://1.bp.blogspot.com/_zHr5qzOZQ9...ArmTopView.JPG
(sorry, it won't take blogspot images with IMG tags, so you'll have to just click the links)

Oh, and I cheated, so that I could clamp it temporarily, I just cut the stud along with a 3" piece of tube off the donor BMX bike, instead of trying to tack the stud on by itself.

[Amberwolf]

I wish there were more cyclists or other low-power EVers on here; I always feel like I'm just talking to myself posting this stuff, since I can't tell if anyone is even reading it, much less interested.

I got some new (well, used) batteries, smaller so I can use more of them for a higher voltage pack. This lets me use the gearing I already have on the bike instead of finding a way to weld a new sprocket on there, which doesn't usually work out very well.

They're out of an old server UPS, so they're not the greatest of batteries, but free is free, and some of them still work fine, at least for now. Use them till they die, then see what turns up to replace them.

There's more info at these posts, including (if Blogger ever finishes the upload) a video of the motor and drivetrain in operation.
http://electricle.blogspot.com/2009/...ships-ups.html
http://electricle.blogspot.com/2009/...est-video.html
http://electricle.blogspot.com/2009/...test-ride.html
http://electricle.blogspot.com/2009/...and-noise.html

[john818]

Originally Posted by Amberwolf

I wish there were more cyclists or other low-power EVers on here; I always feel like I'm just talking to myself posting this stuff, since I can't tell if anyone is even reading it, much less interested.

I'm reading and interested. I'm considering a few builds, and even though they're not much like yours, your info will help me decide which one is best for me.

Keep up the good work!

[Dennis]

I know of a motor you could use for your bike that would give you more pedal assistance with less struggle. I got one of these: https://www.surpluscenter.com/item.a...tname=electric which generally retail for $600 if bought non surplus. I have tested this motor and can say it is very torquey! I don't like PM motors though, but hey for this HP of 3/4 its okay I suppose.

[Amberwolf]

Originally Posted by john818

I'm reading and interested. I'm considering a few builds, and even though they're not much like yours, your info will help me decide which one is best for me.

Any questions or suggestions? I'm always interested in others' opinions of the project.

[Amberwolf]

I've got some new posts up regarding running the motor without pedalling, possibly adding foot pegs so I don't have to keep my feet on the motor-moved pedals, then an idea for a pedal freewheel so that the chainrings and chains might move when the motor spins, but the pedals won't, meaning I can use *them* for the foot rests, as always, and thus be able to instantly engage pedalling mode if I have to (for that "emergency speed", for instance).

It would also keep the pedals from being sort of dangerous as they're moved around by the motor. At the torque levels it has, I could easily imagine the damage it could do to me if I, for instance, got my foot caught between the rising pedal and the bike frame, at the rear of the stroke cycle. Not a likely thing, but it *could* happen, unless it's freewheeled.

It also means that the motor can't control it's own throttle, once I have the tension-controlled throttle working, *if* I can find a way to put the pedal-freewheel adapter *before* the pedal chain itself, meaning if I can get some steel cranks/chainrings I can weld to that will give me the right ratios.

Then I had some thoughts about disabling the freewheel at the rear wheel, so that I can use regen to help brake the bike.

Plus thoughts about a clutch to allow cruising without regen on flats and small grade downward slopes.

[Amberwolf]

Originally Posted by Dennis

I know of a motor you could use for your bike that would give you more pedal assistance with less struggle. I got one of these: https://www.surpluscenter.com/item.a...tname=electric which generally retail for $600 if bought non surplus. I have tested this motor and can say it is very torquey! I don't like PM motors though, but hey for this HP of 3/4 its okay I suppose.

Two problems with that are:
--I'd have to buy something really expensive (not that you would have knownd this, but it'd have to be acquired with zero money--literally right now I am preparing to move out of my house because I have found out I no longer will get enough hours at work to afford to stay here). $170 is more than a week's pay for me these days. Double what I spent on groceries this past month. Ouch. (I'd been planning on a new battery pack but it might be a while now).
--That I'd not really be recycling stuff that would otherwise be trashed in order to make it.

I use some things that aren't in that classification, but I try to stick with that just because in many cases I can, and because part of the fun is in figuring out how the heck to do something with something else never intended for that task.

A third problem with it is that 33 pound weight. Even if 5 pounds of that is shipping crate and packing, that's more than twice as much as my existing motor. I'd rather add another battery for more range.

It's also not actually even *as easy* to use as my existing wheelchair motor, because I would have to then add a gearbox or other reduction to it to get that 1800RPM down to 90-100RPM to go into my drivetrain. There's more weight. I could save some weight by using a very small 11T chainring on the motor and a 164T or bigger chainring on the drivetrain input, but chain at high speeds is really noisy. I don't think I could fit belt pulleys big enough to do that with a single stage on there, and a double stage of that would add even more weight.

That treadmill motor I have, rated at 2.5HP at 120VDC at 7000RPM, is probably easier to use, simply because it is much lighter (about 12-13 pounds, same as the wheelchair motor+gearbox). Even the added two-stage reduction I made for it, 3:1 pulley then 10:1 chain, doesnt' add but a couple more pounds (though it is still noisy). That is based on using it at less than a third of it's rated voltage, though, and I'm not sure how much torque it has that way (should still be a lot based on some things I've seen them used on at low voltage).

[Amberwolf]

Got more work done on the bike today, but too tired to type up anything other than my post at the blog:
http://electricle.blogspot.com/2009/...or-cutoff.html
Pics and stuff, too.

Basically got the controller in a smaller case, changed the MOSFETs for an experiment, added a brake-lever motor-cutoff, described my recharging method of madness, and a few other things.