Powerchair Motors for Bikes...Brushless this time

I used to run CrazyBike2 on brushed powerchair motors with right angle reduction gearboxes, and that was ok, with the only real problem being the repeated chain and sprocket mangling from the incredible torque I could get out of them, and misalignment problems I had due to frame twisting (because of said torque).

Well, now I've got a *brushless* powerchair motor, direct drive rather than gear reduced, to try out.  This thread on Endless Sphere documents my exploration, modification, and testing of that motor, and will eventually show it's first tests on CrazyBike2, and it's later testing on the bike it's intended to be one of the various experimental power sources for. 

That bike is not yet named, and isn't finished yet due primarily to not having a reliably-working welder anymore, and secondarily from not having enough time to do everything yet.  There's a thread on it's evolution over on Endless Sphere, showing it's current progress.   The main thing I needed from this frame was stiffness, to prevent the flexing and twisting issues I had with CrazyBike2 with chain-drive motor power, whcih I still have issues with when carrying heavy cargo.  It'll use a mid-mounted NuVinci 171 developer's kit with autoshifting for a "transmission", to help keep power usage down (although it might not actually make it any more efficient due to the losses the NuVinci itself incurs internally). 

Also, to start it out from beginning as a full-suspension, since CrazyBike2 has broken lots of rear wheels while loaded down because of unavoidable bumps, potholes, and road debris, which shouldnt' cause such problems on a suspended wheel.  It will also use a motorcycle (Suzuki dirtbike, acually) rear wheel, which will take a lot more abuse than the bicycle wheels I have used so far.  I just need a good narrow "slick" tire for it, as the wide knobby it has now isn't really suitable for my purposes.

That's my update for now, hopefully I can keep coming back and adding info to the blog more frequently--but if you are a reader of it, and need more, I tend to post on at least one of my project threads on Endless Sphere ebike forums every day, and sometimes on several of them. 

Xtracycle-style Sierra?

I don't know if it's possible to do this with an actual Xtracycle due to it's frame construction, but I am pondering an Xtracycle-like addon (that will do this) to that Schwinn Sierra I fixed up recently, perhaps with a motor assist, perhaps not.

Specifically so that I am not dealing with a longer shiftline and the problems reported with it where shifting can be finicky in one gear or another, I intend to put a regular rear hub with the derailer still on the Schwinn's dropouts, so the original chainline stays as it is, as does the shifter cable. Then there will be a separate sprocket from that hub to the rear wheel, which will be re-laced to a no-dish single-speed wheel to make it stronger for cargo use. (actually I will probably just take a front wheel with a sprocket bolted to it, for simplicity of testing out the idea).

I will probably build the addon frame around an existing rear triangle off of some other bike. I am tempted to use the one off the white Huffy, simply because it is called a "Nevada", which would make this bike a "Sierra-Nevada". ;-)

But that is a silly reason to pick a frame, so I will more likely start with one of the old chromoly tenspeeds I have, whose frames are way too tall for me to use for myself normally. I'd remove the entire rear triangle from the donor frame, but not including it's BB. I would cut down the seatpost from the bottom end, leaving that extra on the BB itself. Then reweld the seatpost and chainstays to a new crosstube from something else. This would all be welded to a subframe that can then bolt to the Schwinn Sierra's rear frame and keep the whole rear end stiff. It would mount in such a way as to leave a clear chain path between the Sierra's rear dropouts and the new rear wheel position, and would be able to slide back and forth for chain tension adjustment and lock in place to hold it once set.

I would like to make some bottom/side rails that let me rest cargo on them (like some Xtracycles do) that are removable, so I do not have to carry them for typical rides, but instead only when I will carry more than normal stuff with me.

Then a top deck to cover the entire space from over the rear wheel to the back of the seat.

I am also considering a more recumbent seat design that would fit down into the gap that could exist between the tire of the new rear triangle and the Sierra's seatpost/seatstays. Then I would move the steering handlebars back to fit in a bushing in the seatpost, and a linkage for remote steering to a stub-bar up in the original stem. This is a very similar arrangement to Justin's (of http://ebike.ca) cross-Canada bike, and inspired by it.

The problem with such a design is that it reduces the cargo I could carry on it, so I would (as Justin did) likely leave the option of pulling off the remote steering and inserting the original seat and post, and riding it just like that. The 'bent seat would stay, as it would make a nice carrier for some cargo. Well, unless the cargo was too large and needed to fit across the full length of the area behind the seatpost.

Just some thoughts for another possible cargo bike, most likely quite short range in nature.

Let's Build It Already!

Upon pondering some transmission thoughts, I think that at least for now I will setup a system to switch the motors from series to parallel depending on A) speed and B) steering. It is far easier to do this than to mechanically deal with huge reductions and shiftable drivetrains (other than an internally geared hub).

So series wired for startups and slower speeds. Once past a certain speed, will switch automatically to parallel, and not drop back to series until a couple MPH slower than that setpoint. The hysteresis will prevent the switching system from chattering and blowing stuff up. :)

I will need to learn to drop the throttle when the shift occurs, so I don't end up with sudden bursts of speed. I will probably put a light and maybe a beeper on there to alert me to an imminent shift, maybe 1/2 second before it happens, which should be enough to react to until I get a feel for it.

Since the main reason I wanted series motors was so that I could get an electronic differential for turns, it means that turning would need to be done at slower speeds in order to get that differential. For gradual curves it may not matter; have to test that. For sharper turns, such as from a N-S road onto an E-W one, I will probably need that differential.



Hmm....maybe a much better idea would be to build up the second 2QD and tweak them both to run identically when matched with their own motors, then use separate controllers with one throttle, compensated for an electronic differential by having a steering sensor that changes the proportions of left vs right motor throttle. It'd be more electrically complex, but also simpler in a number of other ways. It also leaves me with redundant controllers as well as motors and drivetrains, which is a nice feature.

I think I already have all the parts for a second one, including another metal enclosure (from an old external harddisk) similar to the Jensen inverter case I am installing the first one into.

This also means I can leave the Curtis on the CrazyBike2's motor, to which it is more suited (given that motor's short-term power capability).



I could not sleep last night (again, it's a common problem) so in between dozing just long enough to know I dozed as my head hit the keyboard, I looked up tilt-steering (leaning) trikes, all over the web.

I found a little information here on ES, which eventually got me links to links to links to a place called Jetrike, an open-source recumbent bike / trike project. The creator of it has plans and construction notes for a bike and a couple of tested trikes there, and some of the stuff looks very interesting. The most interesting part is that he has run simulations for the designs to see what would "really happen" before actually building anything. And has data tables and stuff for a few critical types of dimensions and how to work them out for a particular design. The trikes are deltas, but he started on a tadpole according to his pages there. I'd be super-interested in seeing what he comes up with.

However, the link to that project is broken, and there are no updates to the site that I could find since late-ish 2007. There is also a discussion link, but skimming thru it's archives I don't see any indication that he has proceeded with that project at all, which is very disappointing, as he did good work on the previous versions, and has hard data on why some things should or shouldn't be done, and how they might be improved to fix problems reported with various ways of building trikes (including fixes for rear-steering trikes, which are notoriously unstable and potentially very dangerous, due to flaws in layout of the tested versions, apparently).

Anyhow, I have many more ideas on a tilting trike, but I am still not confident at all that I could design something around that concept and make it work safely and reliably. Not with the stuff I just happen to have laying around, anyway.

There are others around as well, and many images and a few clear videos of some in action. I may be able to learn enough to actually design one of my own, though first I need to learn enough about the math involved to grasp the solutions in my head so I can come up with stuff without having to actually sit down and do all that math (at which I really suck).


I think I need to just build the thing first and get experience with a trike, then start working out version two that will have more features on it, probably including tilting.

I might even go ahead and build a pedal-only trike first, just so I can get that part working, and get a feel for ergonomics of the design based around my riding, and THEN work out a replacement for the front wheels/forks that lets me use the motors on there. I've been putting off this trike thing for so long because I didn't have this or that or a way to figure such and such out, etc., and I am really wanting to just get it STARTED!

More Trike Thoughts

spinningmagnets on ES is looking out for internally-geared hubs, which would greatly simplify the switching-gears on the front wheels, and ought to be able to take the nominally 300-350W per wheel I would be putting thru them, as long as I set it up to cut power during shifting.

So I will probably build the front setups simply using regular rear hubs on both front wheels, and any multi-gear drivetrain I come up with for temporary use will be easily removable. I still need a ratio change of around 1:5 to get the 20MPH top speed, from the gearbox output that's intended to directly drive wheels half the size of the ones I'm using for 8MPH.

I have been pondering a way to swap the gears in the gearboxes so that they output closer to what I want to start with. I cannot remember exactly what ratios they are inside for which parts, but basically the main reduction is from the motor shaft's helical gear to the first right-angle gear in the box. Then that has another gear on the same shaft that meshes with the output gear, which is on a lever-type clutch to disengage the gearbox for manually pushing the wheelchairs these came from. I'm pretty sure that the last two gears are different sizes, with the larger of the two on the output shaft.

If the shaft diameters are the same between the output shaft and the first shaft, I can swap the gears so the larger one is on the first shaft, which will give me some amount of anti-reduction (gain?) within the gearbox itself. If they're not the same ID but I have or can make a collar adapter for the difference, I can still use the gears swapped; just have to lathe out the smaller one to fit.

Then I have just that much less anti-reduction to do from the gearbox to the wheels. If the gears are the same OD/teeth or the larger is already on the first shaft, I'll have to do all the work outside the gearbox.


I've also considered taking the motors off the gearboxes and affixing a timing-type pulley directly to the motor shaft but this would require creating a drive-end plate for the motor that supported the shaft, as right now that bearing is part of the gearbox. This is not that trivial a matter to do, for me.

I would then need a much larger pulley on the wheel itself. I can't recall offhand the motor RPM, but somewhere in the 3000 range, I think. That would be a ratio of about 9:1. The smallest belt pulley I have around here is for a V-groove, and it's around 1.5". So I'd need a 13.5" diameter pulley on the wheel!

I can't recall the way to figure minimum number of teeth I'd need engaged for a timing pulley, but I suspect it'd be at least an inch or two in diameter.

Can't really use chain; at 3000RPM at the motor end that would be a helluva noise.


Basically, at 9:1 reduction, compared to 1:5 anti-reduction, I'm better off sticking with the gearboxes and using bike chain/sprockets for output shaft to wheel transmission. It's not as "efficient" as less stages of changing ratios around would be, and it's heavier, but it is a lot easier to do, with less stuff I have to build from scratch to make it work.



Now, one problem I have is that for the right side wheel, to get power from the motor to the wheel, I need the motor on the right side of the wheel, just like it will be on the left side wheel. But that would be problematic for reasons of safety, clearance, and keeping the motor itself safe from damage. So the motor must go on the left side of the right side wheel.

That leaves the issue of how to get power to it. To use a regular bike hub for it isn't that big a deal, as I can just bolt a sprocket (or weld it) to the left side of the hub. But I will want to use the internally-geared hubs for this later, and those will need the sprocket on the right side of the hub. Meaning I have to get power around the wheel somehow.

Thus, I will probably end up using an extra hub at the rear of the fork, to act as a jackshaft and pass motor power thru to the other side of the wheel. I can simply use a front hub since I don't need to put any freewheels on there, or spoke a wheel to it, and just bolt the sprockets on thru drilled-out spoke holes if they line up right. An adapter plate if they don't. Or weld them on, one on each end.

I just weld on some little dropout tabs to the fork near the U end of it, just clear of the wheel.



For the fork itself, I'm going to need to take some 24" or 26" U-forks, and cut them in half at the stem end. Then weld a tube across there to space them far enough apart for a rear hub to fit in the dropouts up front. But since the internally-geared hubs need dropouts that are slotted to fit them, and I will need enough dropout length to use to adjust chain tension (no derailers), I'll need to remove the original dropouts and put on some from scratch or from BMX bike frames.

Alternately, I can just build the forks from scratch, which would simplify making them significantly, and give me control over every part of their design, as well as make them the same for each side, mirrored. (well, mostly)


Another thing I've been pondering, and that is which way to make the forks--vertical or horizontal.

Horizontal will keep more weight down low, which is very good for a trike. But it means the motor mounted on there will have to have it's weight swung back and forth on the pivot every time I turn, which will act as a pendulum weight and make steering a tad more difficult--it will tend to resist starting to change the wheels direction, and resist stopping that change, too.

Vertical will essentially fix the latter, but will place at least a little more weight up higher. I can still mount the motor itself so that it is centered about the axle, and that will keep most of it's weight low, but the fork will still be higher up and that weight will be above the centerline, giving the trike just that much more susceptibility to tipping in turns, especially if I use the kingpins/pivots up at the top end of the forks.

If I mount the motor vertically on a horizontal fork, it will end up as the best compromise, but it will interfere with the steering pivots and kingpins, unless I move it farther forward, and then the pendulum problem reappears.

Probably I will go with the horizontal fork, and change it if it doesn't work out right.


I've been going back to my old trike research and rereading info I found then but didn't apparently fully comprehend at the time. Now I have seen enough stuff in action and worked with various things in steering, and I understand them better. I think if I had built a trike before, unless I had simply copied someone else's design, I would have ended up with an unsafe or unrideable trike. :( Now I think I know enough to make a passable first shot at it. ;)


I am certain that I got lucky with CrazyBike2, in that it's configuration ended up working fantastically well for something so randomly chosen at each point in the process. I'm fairly good at the by-guess-and-by-gosh process, but it doesn't always work. :roll: The trike needs more thought put into it, and more choices of parts based on design rather than just whatever I have laying around. That said, I think I have a handle on it, and might be able to start building it in a month or so. Less if I'm lucky enough to figure the rest of the design out sooner.

CrazyBike2 Stalled

Not much progress on CB2 itself. Seems like every time I sit down to work on it either I find a serious problem with whatever it was I was about to do to fix the chainline stuff, or something happens to pull me away from it. Or fabricating something turns out to not be possible with the tools I have (or I don't have the skill to do it yet). It's kind of depressing. At least I have the trike design in progress to get excited about. :)

Using that smaller chainring off the Trek is impossible. It would bring the chain itself down to the point it would cut thru the frame. :( Any guide I put on there to route the chain around the frame would probably break under the motor power, probably when I have it heavily loaded and am far away from home. :roll:

To keep the chainline straight on the top where the load is, I have to keep a large chainring on the receiving crankshaft. So it is back to fixing one of the previously destroyed ring sets. Maybe I can mix and match them well enough to double up thinner rings, then use BMX chain for strength. Bolt or weld the ring set together.


Considering welding a threaded section from either a BB cup or a rear hub to the motor shaft's hub end, then putting a freewheel cassete smallest sprockets I can get away with on there. That would get me a freewheel so that I would not be driving the motor when pedalling.

Also considering taking a BB cup and welding it's cup end to the right end of the threaded part of a rear hub. Then welding it's nut end to the face of a steel square-taper crank. The cup would need to be bored out enough to be able to get to the nut and crank threads, so I could still tighten or remove it later.

That would give me a long enough threaded cylinder to do what I originally set out to do for leftside chainrings, which was to put a couple of freewheels on that threaded cylinder with spacers to line up the chains as needed, and allow both motor and pedals to drive the wheel without driving each other.

Problem is, I am not sure that the welding would take the torque, or that the crankshaft itself would take it either, with the load cantilevered out that far. Originally the custom-made cylinder design would have had the motor load still over the actual crankshaft, but both of these would end up out beyond the end of the shaft, putting quite a load on the welds.

So...CB2 is stalled.

Lithium Traction Pack From Scratch--Update

Not much progress here yet. Still trying to find enough time to test the cells, sort them, and then find a good way to assemble the packs.

A new problem with doing it is that the Sorenson I had been using to charge the batteries on CrazyBike2 before, and was going to use to charge up the NiMH packs (from deardancer) and test and charge the Li cells with, just sparked and smoked when I turned it on last night, even though it wasn't connected to any load yet. It's a linear supply, and does not require an external load to operate, so something must've died in it during power-on-surge. A transistor burned and a resistor smoked, and a couple of traces on the board's cardedge connector vaporised, too.

I've got three others (only 40V models) that are not working for various reasons, so I will need to check their boards for the values of parts, and then see if I can trace out enough of the circuit to ensure replacing the blown parts is all that will be needed, so I don't smoke more stuff when I turn it back on again. :roll:

Maybe I'll get the others fixed while I'm at it. :)

I did have another idea for charging the NiMH, though: I already had two little NiMH chargers for AA batteries, and I found another for a couple bucks at a thrift store, so now I could charge up to twelve cells at a time. All three chargers will charge either two or four cells at once. They are all microcontrollers or dedicated chip chargers, so they should be safe to use with any NiMH cells.

I am considering putting charging taps on every cell in the NiMH packs, in connectors of four cells, and one of two cells. Then put a mating connector wired to the contacts on each little charger so I could not only plug in to these cells, I could also still use them for the AA and AAA cells I already use them for (for my flashlights/headlights/taillights, etc. on the non-ebikes).

Then I would be able to charge three sets of cells in the packs at a time. On the 36V pack, that's 30 cells, so two charge cycles for 6 of the 7.5 sets in it, and one more charge cycle for the other set plus 2 cells. On the 24V pack that's 20 cells, so only two charge cycles total (one for 3 of the sets, and one for the 2 full and 1 half set).

The whole pack will not get that warm this way, and though I will have to manually plug and unplug the charging connectors after each cycle, it will let me safely charge the packs.

Well, assuming I don't burn out the chargers doing it; they only put out less than 500mA charge current. Well, one of them can put out almost an amp charging current if it's only charging two cells. I'll try it out with the cheap thrift store one first. It's the model down from one I already had, and is an Olympus BC-100.



I'm also considering taking a bunch of old celphones I have that are broken in various ways, and wiring them up to charge cells. They're all isolated from each other, so I could theoretically charge the pack "in place", with charging taps coming out of it for each cell, and a charging connector. It would never be a fast charge, but it would be possible, though a lot of work.

I would need to take the little BMS board off each celphone battery, and lay them all out on something flat. Then solder wires from the cell connection tabs to the interconnect that would go to my pack cells. More wires from each board's input connection tabs to the celphones themselves.

If I have enough celphones that actually give me a display (many have broken screens or even broken-off flip tops) then I can even monitor the charging process via the little battery meter on the displays. Not much of a meter, but better than nothing. :)

Schwinn Sierra: From Junk to Ride

I decided for now that enough of the Schwinn was intact and in good shape that I'd spend a couple of hours and fit it out as a rideable spare bike, even though it is has no suspension at all, and is a regular straight-top (men's style) bike, which is really hard for me to get my leg up and over.

But it is very light. Even with the little rack I stuck on there, which is cheap steel and about 2 or 3 pounds by itself, plus the Stanley light full of 12 AA batteries, I can still lift it with one hand (not with my backpack/helmet on there, though).

I stuck the original front Kenda road tire off of DayGlo Avenger on there, as it is a lot better than the disintegrating front tire it had, and the Kenda Krossroads off the Trek, which is slightly better than the Kenda Road. Unfortunately, this Kenda Krossroads has the same problem my other Kenda Kross tires had--the sidewalls are not made right, and they shed bits of rubber off the fibers, eventually splitting along the diagonal fiber lines and coming open far enough to let the tube bulge out. This one is going to need patching inside just like the other two do.

I like the tire *style*, but their QC and/or sidewall design sucks. I sure wouldn't buy Kenda tires new, based on my experiences with all the ones I have had so far, including the pair that came new on DayGlo Avenger when I originally got it as a new-in-box Columbia Comfort Bike back in 2005 (of which the front tire on this bike is one).

That front wheel has the Slime thorn-resistant pre-slimed tube in it, too, as the original thin tube in there had several patches already, and was sticking to the inside of the disintegrating tire such that I didn't trust it.

This is what it looks like with no flash, and it's lights on.

My helmet light is on, too, and it is shining at the chair's right arm. It's a very diffuse LED light, without much of a spot. Lights up stuff close fairly well, and does a decent job of lighting up reflective road signs, license plates, etc, but not the actual road.

The Stanley light *does* have a really good beam, enough so that you can clearly see it on the wall in front of the bike (only a foot away, but still)

That spot stays a spot far enough away that I can't see enough light back from it to be useful, probably about 50 feet on road surfaces, farther on lighter-colored objects and much much farther on reflective ones.

It's a point source light from a distance, and quite bright; I keep it pointed at the ground about 20 feet ahead most of the time on the roads. Farther on unlit trails/canals. It's clamped to the bars with 2 hose clamps, like my other flashlights have been, and like the little red one is clamped to the junction of cargo rack and rear triangle.

I had to replace the sheaths for the shifter cables, though the cables themselves were fine. I swapped out the freewheel cassette for the one off the Trek, as the one on the Schwinn was very noisy, and the one on the Trek was virtually silent. I'm sure the original would work better if I serviced it, but I wanted to try the bike out for a bit before it got too late tonight, and I was getting hungry.

I tested it out for a few miles tonight, going to the store and stuff, and it worked well. Only problem I had was that the "Primus" thick tube that was already in the Kenda tire in back blew a hole (slit, actually) too big for even Slime to save it. I had to flip the bike over, peel the tire off the rim, and patch it, about a mile into the trip. No problems after that.

The hole was about 1/3 of the way up from the inside circumference of the tube, and looked like it was from someone using a screwdriver as a tire-iron, but on these tires and rims it's not even necessary to do that. They easily roll off the rims when deflated, which makes for easy fixing if something goes wrong, like above. I didn't even have to take the wheel off. I didn't see the mark when I originally swapped this onto the Schwinn's rim, but I did not look that closely at it. My mistake. :(

This bike is actually a joy to ride--it is so light and is geared right that I can start up without much knee pain, as long as I am not carrying anything. Adding the backpack with toolkit, pump, etc, plus wearing longjohn bottoms & top under the jeans and tye-dye long-sleeve sweater (for warmth in the chilly evening, made worse by the breeze from riding), was enough to make it harder to ride but still better than DayGlo Avenger even without it's cargo pod and rack.

I *don't* like the lower handlebars, though, so I will have to do something about that. The stem is already most of the way up, though, so I can't get enough height from it to help. I will probably have to change the handlebars to something that reaches farther up/back.

It is quite a tall bike and is not a joy to get onto. I can barely stand astride it, with the top tube against the seam of my pants. Wouldn't wanna slip off the seat. ;-)

I also don't like the seat, which is the original Schwinn narrow hard seat. Like all of them, it doesn't fit me and it's also slippery, so I can't seem to stay on it. It's a quick-release so I will probably use my shock-post seat if it fits in this tube (it might not). That seat is wider and at least somewhat tolerable for longer rides than a couple of miles. This one is mildly painful after only about a mile and a half; I probably could not ride it longer than 5 miles even if my life depended on it. ;-)

I'm pretty sure it was actually meant to have 700C rims on there, or at least something larger than the 26" that it came to me with, as the brakes don't adjust down the rims very far--the top edges of the brakes just clear the top of the rims by a millimeter or so at their lowest adjustment, but would go at least 1/4" higher--enough to ride completely on the sidewalls of the 26" tires!

If it did have taller wheels, I would not be able to ride it, though. I would be unable to mount it without holding it sideways so far that I could not push it upright to get it going, and I would be unable to dismount at stops, forcing me to lean over on one side while staying in the saddle. I'm not sure I could startup from a stop then, as most of them are on slight uphill inclines. It certainly wouldn't be easy.

Anyway, it's a good bike.

Throttle Lever, Gas Springs

More parts donated, including a lever for my throttle

That is in the max output (max pot reading, 5K) position.

That is in the max physical pot rotation position.

That is at the zero pot position, centered on the pot (the pot, like the lever, is made for a reversing motor controller in a wheelchair).

I don't yet have the spring return on it, as I need to make something to connect from the throttle lever into the spring's "catch" for the return action. Should just need a little bracket to wrap around the far end of the lever's pivot and back in an L shape into the spring's "catch".


and some interesting actuated "gas" (probably hydraulic) springs.

The springs are neat because they have a little push rod in the center of the strut, which must be pushed in before the strut can move. This is done for ride-height adjustments on the chairs they come from (using a cable and lever similar to bike brake levers but smaller), but the nice bit about this feature for me is that they would let me "disable" the spring action if the bike was too heavily loaded to work without bottoming out, simply by raising the lockout lever.

Or they could be used solely for their ride-height adjustment ability, and not as springs at all. That would let me explore different front and rear heights to see what worked out better for height for clearance of road debris, curbs, etc, vs stability in turns, before permanently building that height into the frame (if ever).

More Bikes for Parts

Day before yesterday while helping a friend move stuff, I scored a couple of nice but very beat up bikes that happen to have square taper cranks with several things I have wished I had for a while: bolt-on spider/chainrings for the triples, trigger shifters, and some good derailers/shifters for 6-speed cassettes.


One is a larger triple than the other, and I think it is aluminum or some alloy for the rings (as well as the spider/crank. I can actually wiggle it side to side between spider legs.

The other triple is much harder, does not wiggle, and has that darker brownish tinge of titanium, although I am sure it is just plated or anodized to that color rather than actually being made of titanium. I sure wish it was, as I doubt I could break it if it was. ;) The crank/spider is still aluminum/alloy, which is fine. It's a lot smaller rings though, so I'll need to use the smaller ring on the motor, maybe even cut it off and replace with an even smaller one.

The crank rings on the Trek do appear to be very hard metal on the largest ring--it does not even have it's tooth count stamped in it as the two smaller rings (of a different color metal) do. It is stickered as a Shimano Hyperdrive C. It's a 42T, and the others are 34 and 24. There is minor damage (chipping?) on certain teeth and tips, but it is in better shape than most of the rings I already have around here.

Being a Hyperdrive C tells me more certainly that the original wheel/cassette isn't on the back, because AFAIK these were meant for an 11T rear smallest sprocket.

The rings on the Schwinn are larger, at 48T, 38T, 28T, but are definitely weaker than the Hyperdrive rings.

I am going to see if I can work out a new driveline on CB2 for the motor/pedals using the Hyperglide as the receiver. Kind of a waste, as it won't be used for any shifting. :)

I will probably just put the old strong single-ring cranks back on CB2's pedals.


There are a number of other nifty parts on the bikes, too, including even the frames, which appear to be nice cromoly, and are light enough I can pick them up onehanded even with the whole bike together, though I can't carry them far (I'm a wimp and my knees and joints hurt a lot).



One has Shimano trigger shifters, but they weren't working. The trigger shifters are part of the brake lever mounts, too. The cap on one is missing; hopefully it is only a cover and not a functional part.


These may end up being perfect shifters for the trike, since I will not have my hands in my field of vision with the tank style underseat steering, so I also can't see what gear things are in or what position the shifter lever is in. A trigger shifter always returns back to "home" after each shift, so it would be easier to shift with "blind". In theory. I've never used one.

I did a little bit of cleaning of the trigger shifters, and now they work fine. Just had dirt in there keeping the mechanism from moving the ratchet. I'll have to make a cover for the right (rear) shifter, or that will continue to be a bad problem.

The other has Deore lever shifters for a 6-speed rear cassette and a front triple, which is what I have on the CrazyBike2 right now. The Deore shifter I have on CB2 is for an 8-speed and thus doesn't shift properly due to differnet ring spacing (I dont' have anything with an 8-speed cassette).

Both shifter cable housings were disintegrated at the shifters, as you can see.

One uses vbrakes, one uses side-pull linears with the noodle. The vbrakes appear to be almost new pads, the others have some medium wear on them.

There is only one good tire on there, a Kenda something-or-other. The others are typical knobby stuff, though one of them is much less so than the others.

The Schwinn is a non-suspension bike, and the Trek is a hardtail with front shock forks that don't appear to work. They are labeled Skareb, though parts of the lettering are worn off so I can't read everything on it.

They appeared to be hydraulic rather than spring, but turned out once I found the manual online to be pneumatic shock and hydraulic damping. There is a lever on the top of one of them that I originally thought was supposed to adjust the ride/travel and thought was missing on the other one, but it turns out to be the damping adjust, and is only supposed to have one.

The other is a schrader valve, which I aired up to about 100PSI based on the manual and some posts found on an MTB forum, and it now operates as a shock. :) I haven't opened it up to check the oil, but I suspect it's empty or near so (or the valves are bad) as there is no damping at all, regardless of the red knob setting.

It appears based on the manual to be easy to disassemble to check it out and/or fix, once I have time to clear off a table to lay out all the (presumably oily) parts. :)


One bike has wide-flanged hubs, which could come in handy for bolting diskc brakes to via adapters, but neither has any disk brake mounting holes on the hubs. The shock fork above has the mounting for the brake calipers, though. They're all 26" wheels with aluminum rims and hubs. Don't know if the spokes are good ones or not. I'd bet they are better than the cheap junk on most of the wheels I have.

Turns out the rear hubs on both are regular freewheels, and I suspect they are not the original cassettes, either, as neither one even has much in the way of the little shifting-helper-ridges and contours on any of the sprockets--they're pretty much flat on the Trek, and just have the twisted tips on the Schwinn.

The rear hub of the Schwinn:

The hubs/rims on the Schwinn could be original, they appear to be at least decent quality ones and both match. Spokes seem a lot better steel than the Trek, as they don't just bend (even the loose ones) with finger pressure. There is a spot on the rear rim that is dented/bowed out a little from what was probably running over a rock (there's no matching one on the other side, so not likely a pothole or curb jump). They're even reasonably true.

I'm pretty sure they're not the original rims on the Trek, as the rear is a VERY cheap steel rim that has a horrible welded seam, with cheap steel spokes on it. The front wheel isn't that much better but is at least intact. Neither is true at all.

The Trek is really a mishmash of different bikes, and some of them were very badly put together, including it's rear hub. I thought maybe it was just loose, and jokingly thought it might be missing the bearings, as it was so wobbly. Actually it was missing the cone nut, and a regular washer had been put against the bearings, with NO LUBRICATION AT ALL, with a single spacer-style nut tightly up against it. Regular nuts just threaded there as spacers up to the dropouts, but not threaded up to the washer very hard. This was the result:

Yes, that is a flat-sided bearing, and it's not the only one.

All the bearings are actually stuck to the race so hard I can't pry them out; I suspect they're partly welded in place by friction heating. It even looks like the bearing cup itself is separated from the hub's outer edge, and pushed into the wheel some.

This is all on the drive side, so the stress broke the spoke you see above, and damaged others.

Suspension And Motor "Modules" by Gary Payton

This looks like an interesting idea I might be able to adapt to a tadpole trike for front wheel drive.

I could use two of the smaller powerchair motors on there, one on each wheel, perhaps.

I had previously briefly considered two powerchair motors driving the wheels directly from their axles, but that would not have allowed pedalling if the motor system failed or I ran out of power. The above linked design would allow that, as I could put a dog-clutch (or freewheel) in one of the transfer pulleys, which could use either belt or chain.

Also, the motors directly driving the wheels would not go very fast unless I overvolted to perhaps 60-72V, given the wheel size and original motor/gearbox speed. I'd rather not have to carry *that* many batteries. At original voltage, they're meant to go around 4MPH with 10" wheels. So the 20" wheels I want to use on the front would still be pretty slow, less than half the max allowable speed on ebikes. I'd like to be *able* to go 20MPH, even if I don't do it much.


Of course, I found this idea via the V Is For Voltage forum *after* I started sketching up some ideas for the suspension and frame, and setting my brain on the search for a workable geometry with stuff I already have laying around. ;)

So now I am going to see if I can reprogram the "offline mental search" to figure out how to make these modules instead, as they would simplify the frame and steering setups. Plus, I would have front wheel drive with electric, and could leave the rear wheel drive as pedal-only, reducing the stress on that wheel, "spreading the load" as it were. Simplifies the chainline and drivetrain integration, too, and keeps all three drivetrains independent, for multiple redundancy.

2QD Still In Progress, Now Using Curtis 1204-410 Controller

Since I have had so very little time to work on anything recently, I haven't finished the 2QD controller repairs or the physical repairs to the bike (wheel, chain).

The major problems were just the power output section (bottom two MOSFETs blown, gate resistors burned open as they were designed to). But one minor problem that kept anything from working right was a 9.1V zener diode that was only allowing 1.45V! So there was no internal power supply to run the entire comparator and feedback/control section, which is the majority of the controller.

I fixed that by replacing the zener with a 5.6 and a 4.1 in series, which while higher than the original still allows it to work. This got the main section working again, and now I just need to finish the power section as described a couple of posts back. I have wanted to use a different case for a while, so now is my chance.

Since it is taking a while to figure out and then make the holders for the FETs to line them up and keep them tightly against the case inside, and to polish the aluminum and the FETs for flatness and smoothness (for better heat transfer, since I have to use thermally conductive / electrically insulative pads, too), I decided to take a quick look again at the Curtis 1204-410 I have had for a few months with little time to troubleshoot.

I let it sit on the bench powered on (but not doing anything as it doesn't respond to input), for a while, and suddenly it started working, the motor attached to it began slowly spinning (the throtle was just a regular pot set to barely on). Apparently once it got warm enough (from me having the oven on to warm up the room), a connection was made well enough to start working.

There are six interconnect wires between the Curtis logic board and it's power board. Two carry B+ and two ground, and the other two carry signals. One is the PWM output to the FETs, and the other looks like a feedback from the FETs as it is time-shifted just a tiny bit late (which I can barely see at all with my old 531A), but identical to the PWM waveform.

The solder joints on them must've been flexed or vibrated enough to crack them, so they would only make connections good enough to work when warm or hot. Over 85F, anyway. Under that, they might work and might not. I reflowed the solder and now they always work.

Since it's a 36-48V 225A controller for brushed PMDC motors, it can be used in place of the 2QD, so for now I put it on CrazyBike2 and verified it works with the bike. I can use it until I finish the 2QD rehousing.

Now I need to build a new rear wheel, move the chain and some shifters and stuff from one of the spare bikes I got for parts from someone for Christmas, and finalize the new throttle control setup, and CB2 will be ready to ride more than just for tests.

I also cobbled together this temporary throttle lever and mounting, for using a powerchair's spring-return throttle on CB2.

The spring is so strong that without a pretty long lever, I cannot keep it pressed down for very long. Sorry the pic is so dark, but the flash keeps shining off the metal and the camera autodarkens the rest of it to compensate. :(

The aluminum bars are just end-pieces, uncut, off the rackmount fan enclosure from the same old studio-type Sony VTR the gray transistors from the last post are from. I'll probably wind up modifying a brake lever setup to use for this instead, as it will already be designed to clamp to the handlebar, and it has a long pivot arm.

Optionally, I considered using a lever-style shifter, but it is more complicated to set up for this, and it is also a much shorter lever.

UPS And PC Power Supply Parts Bonanza

A bit of salvaging of some old computer power supplies and UPSs (most of which were found in alleys or roadside on bulk trash days, over the last few months, but sat "intact" until now due to lack of time) netted me several pounds of parts (not counting the toroids or transformers!), including the stuff shown in the pics below.

Bunches of small value caps, diodes, zeners, transistors, mounting screws, heatsinks and clips (and thermal pads), and lots of resistors not yet taken off the boards (not in pic), several TL431A and some LM317


Some very old 100V+ Vce type transistors in PNP and NPN, off some boards from a Sony VTR (I never saw the VTR, just the boards)

They'll be used to replace some lower voltage 2222's on my 2QD so I can up it to 48V+ usability.

Bunches of small signal transistors, 50V Vce types, a bit better than the 2222 but not much.


A few beefy dual-diode (common cathode) units, one of them up to 40V at 50A!

Also about three times that many smaller TO220 versions of these, mostly in the 40V 3A range. All can be used with heatsinks to parallel unequally-charged battery packs in a pinch.

Of course, there are lots of large caps, too, in low and high voltages, and many form factors.

MOSFETs; lots of them, too, though mostly lower-voltage types, and generally fairly high RDSon.

Some IC's, too. Optoisolators, LM339 and LM324 chips, other single or double op-amp chips, some logic chips (74x series), some "house branded" chips in the UPSs which probably means they're ROMs or pre-programmed MCUs. Some standard PWM SMPS control chips, might be adaptable as controller chips.

Transformers, connectors, toroids, cables, wire, heatsinks, switches, LEDs, etc. Fans, too, but the fans are all defective. They might have usable hall sensors in them, though, as long as I don't need linear sensors (they're more likley to be switching types).

Most of the desoldering was done by carefully using a very small propane torch to heat the thru-hole lead areas, while gently tapping the PCB on the bench (outside, so any fumes would not suffocate me). Some things required a solder-sucker and regular soldering iron.

I should be able to build up my other 2QD controller out of what's there, plus have plenty left over for other projects for a while to come, such as a BLDC controller.

There are LOTS of electronics that have all this stuff salvageable if you have time to do it. I generally spend only a minute or two at a time, over days or weeks, and end up with what looks like "Christmas at the parts store". :) Even if only half the parts worked when done, it'd have saved me enough money it'd stil be worth it.

2QD Repairs, Modifications, Thoughts, Part 2, Used NiMH Packs

Some pics of the modification/repair in progress.

This is the old Jensen inverter case:

The three long caps "below" it are the ones from the UPS. The smaller one to their right is the one I originally had on the 2QD, and it has been getting hot with generous motor use.

An end view of the box with all the controller parts loosely fit inside it (except for MOSFETs)

The two large holes on this end used to house the AC outlets on the inverter. The switch on the right is one I've had laying around unused for around 15 or 20 years; bought at Radio Shack for some forgotten purpose. ;) It has an orange LED in it that will be used at VERY low brightness (20K resistor) to tell me if the controller is powered on and the throttle connected, and not open-circuit.

With the case open, you can see the general fit of parts. The three caps with the main power supply wires feeding between them will fit on one end/side. The MOSFETs will be clamped to the left side, and hand-wired to the PCB.

The PCB will fit in as seen above, and is cut down from it's original length to do so.

Another shot of the layout.


The 2QD PCB freshly cut.

It is separated just at the gate resistors for the lower leg of the half-bridge, as that is the length needed to fit inside the Jensen case.

The MOSFET end can be used as-is to keep the MOSFETs together, and easy to mount to the wall of the case.

They do still have to be electrically insulated from the case, as their heatsinks are electrically active and different parts of the circuit.

I am not sure when I will finish it and get CrazyBike2 back on the road for the 30 miles it needs to get to 1000 miles, as time is a scarce commodity right now.



To add to my growing collection of power sources, a couple of NiMH packs arrived tonight:

USPS kind of squished the package but didn't damage the contents.

They did put a nice notice about the oopsie, under the shrink wrap plastic they put on to hold it together.


The packs themselves:

The white one is a Sanforce 24V pack. The green one is a 36V pack from a Giant Suede.

I know that the 24V pack was damaged a bit by a thermal issue during charging, so it reportedly now has voltage sag if more than 7A is drawn from it, even at full charge. It's made of 10 super-F cells of 13Ah each. It's charging rate is 1/10C, for 16 hours. Don't know the original discharge rating, but now it's about 0.5C.

The 36V pack's original specs were 12 pounds, 9Ah, rechargeable in 4 hours (so charging at about 4.5A or 0.5C), and originally drove a 240W hub motor. Don't know what it's discharge rating is.

I dont' have a NiMH charger, so will have to use the Sorenson and careful monitoring for now.

I'm considering putting them in series for a 60V pack, then modding a 2QD for that high a voltage operation, and putting them on DayGlo Avenger along with one of the various motors I have around here, with appropriate reduction system. There's a 1/3HP 100VDC weedeater motor I might try, or perhaps a couple of my radiator fan motors in series. Have to see how things work out with CB2 first.

2QD Repairs, Modifications, Thoughts

The repair of the controller has turned into a modification session, too. So it is taking considerably longer than I originally expected or intended.

I'm upping it to 48V capability, changing out a few transistors and whatnot, as well as installing the whole thing into a better case that will provide heatsinking over it's whole surface. The case used to be for a Jensen 300W car AC inverter that doesn't output anything, which I gave up on fixing for now (I can always rehouse it later).

The extruded aluminum case is not very large but is big enough to hold the 2QD board with the power end cut off, 3 very tall low-ESR caps (75V 1500uF each) off that giant UPS board instead of the dinky one I could fit on the 2QD PCB, so much better power filtering, and plenty of surface area to bolt multiple MOSFETs to. Plus I can seal it up for watertightness and still vent all the heat outward, unlike the plastic PacTec project box I had it in before, with the tiny heatsink out the end of it.

I'm still waffling back and forth on whether to just use the TO220 style FDP038AN06 FETs I already use, or the higher-power-handling but higher RDSon TO264 style NTY100N10 FETs I used so well for so long on the original rebuilt ScootNGo controller.

Either way, I have to hand-wire the FETs to the control PCB, as there is no way to fit the whole PCB in there in a way that lets me bolt the FETs directly to the casing, without removing the FETs from the PCB. So I cut the entire end of it off from the gate resistors on, and will just run wires to each FET and then bolt them to the inside of the case, using insulating pads to keep them electrically isolated between the upper and lower halves of the halfbridge.

The case also has a spot for an automotive blade fuse. I am not using it now, but I may wire it in later, once I have an easy way to set a limit for the current on the 2QD. Right now the 2QD limits current via a voltage drop measured across the MOSFETs, so it depends on their RDSon. Since the RDSon of the MOSFETs I am using now is so low, around 3.5mOhms (actually half that since I've got parallel pairs), the current limit is apparently very high. Beyond 153 Amps, at least.

There is a current limit fine adjust resistor, and it's coarse adjust next to it, so I just have to figure out the circuit so I can work out what potentiometer I can install there to give me a good range of limitation I can use, for as low as 5A to as high as 50A (more if I have MOSFETs installed that can handle that). Then I can also use this to test for various different limitations, such as batteries that can't supply as much current, like my Li-Ion and a pair of well-used NiMH packs someone on ES is sending me (which might put out 7A on a good day).

Also so I can test for how well it performs at the actual legal max of 750W. ;)

I've also been charging all the SLAs I have around here for the last week or more. Some of the UPS ones simply won't charge well, but I am still letting them trickle charge in hopes they might recover at least a bit. I think that with the two newer ones that came in that most recent powerchair case, I will have 7 good ones in the 17Ah range, and 2 not very good ones, and one dead one. Plus the three 31Ah U1s I'd started with but changed out due to weight when I got the 17Ah UPS batteries. One U1 seems a little weaker than the other two.

I haven't done a full discharge test on any of them yet, but will do that using the Turnigy meter to get an idea of how many Ah I can realistically expect out of each one, including the three already on the bike.

Blown MOSFETs Due To Chain Jam, Possible BMS Arrives for Li-Ion Pack

I have been having balanced karma of late--every time something really good happens, something equally bad compensates.

Yesterday on the way home from work the bike's rear chain (regular bike drivetrain part) somehow derailed and got tangled up, which actually pulled the entire right end of the rear axle and the derailer bolted to it off the dropouts and bent the rim up against the chainstay on the other side (the left end stayed bolted in), and then everything jammed and both bottom-leg MOSFETs blew.

The power meter registered over 3500 watts peak, 153 amps peak, which is a more than any of it is rated for--the MOSFETs I installed in my 2QD are only rated at 80A continuous, and can handle ~150A for *maybe* a second absolute max, with sufficient cooling (which they don't have in my setup, by any means). So it's no surprise they blew up.

All that only took about half a second as I was accelerating away from an intersection, crossing two lanes to get to a left turn I have to make to get home without going down a very busy stretch of road.

Then I had to drag the bike across the rest of the lane (while cars that weren't yet coming when this all started kept trying to go around me instead of letting me get out of their way!), up onto the concrete median, and spend an HOUR with traffic roaring by me, while untangling the chain enough to get the wheel off, unbend the rim and true it enough to get it able to roll. Then I had to take out around 6" of chain due to bent and broken links, and set it up to run only in lower gear in front since it was now too short for the big ring. Plus I had to take the motor chain off, since my pedals are linked to it and it is nigh impossible to pedal the bike without the motor running otherwise.

After that it was a heck of a ride home, at about 9MPH, which is just above the unstable speed of the bike, and I was totally worn out when I got home (and then had to go to a different job as handyman for someone else).

I didn't have the camera with me to take pics of the chain/etc, but wow, it was awful looking. It looked like someone had hit my rear wheel from behind and then stepped on it sideways, but it was just from being yanked so hard by the chain as it tangled.

The frame and dropouts all appear intact, but the wheel was seriously messed up. I will need to take it completely apart, restraighten the rim, and then re-lace it to get it back to anything close to really true.

The derailer cage was slightly bent but not badly, but the bolt that secures it to the little shaped nut that recesses into the dropout behind the axle had sheared thru as it was all pulled out. I am just lucky that I carry spare nuts/bolts in the toolkit, one of which happens to be the same thread pitch and diameter as that bolt--it is a bolt from a rackmount kit--it's so long that it prevents use of the highest (smallest) sprocket on the rear cassette, but as I had to pedal with no assist there was no way I was going to be shifting up that high anyway.

I guess the good news is that I *could* fix the problem on the road well enough to get home.


Here's some pics of the controller with toasty MOSFETs, before repair. I still haven't had time to go back and fix it yet; just replacing the MOSFETs and gate resistors (whcih also burned open as they are supposed to) didn't fix it. I'm too tired to try more now, after another day of work. Tomorrow and the next day I have to go help do a roof and some other things, so I won't be able to do it then, either. Fri and Sat I'm working again, so I don't know when I will find the time to finish troubleshooting it. Maybe Sunday. Should be easy, when I have time and am not too worn out to concentrate. (writing this post has taken several tries).

A close up of the damaged area. The discoloration around the screw on one MOSFET is actually the melted remains of the plastic insulator ring...it's still not shorted to the heatsink, but that insulator is totally destroyed from the heat.




This blown LiFePO4 BMS (sent by an Endless Sphere forum member) arrived today:

All that is known about it's problem is that a puff of magic smoke escaped from it somewhere, but not specifically where. With luck it's the MOSFETs, as those I have around here already.

Once I find and fix the blown part(s), then if I can figure out how to change it's HVC and LVC voltages to match those of my Li-Ion cells, I can use it as a BMS for my custom-built pack.

First, I just need to invent a time-machine that gives me extra time to do everything and still get enough rest....

More Batteries, More Boxes, More Chargers.

Recently donated was another pair of old wheelchair batteries in their box with a charger. All of these are useful, as the batteries are the same size as my 12V 17Ah, but they are 20Ah. The box is an interestingly useful shape, split to lock in over a central electrical connection, but in this case it is wide enough to fit over a top tube! The charger is a 4A 24V charger almost identical to the 3A charger I already have.

First, there is the possibility now to hook up both chargers like this:

if I change the pack to a 48V using four SLAs instead of the three I currently use. I was planning on that anyway, with the fourth to go in the rear triangle once the suspension is done. This would let me simply plug in wherever, and charge up the batteries unattended with the automatic chargers' own 3-stage normal charging, instead of the two ways I do it now.

At home, for overnight charging, I set the big heavy Sorenson for 44.5V and max current, then plug it into the pack in place of the motor controller.

On longer trips where I can recharge along the way, I carry the 3A 24V charger, which is only a couple of pounds, along with an Anderson that has a jumper wire across it. Since it only charges two at a time, I unplug one battery and plug in the jumper in it's place, then plug the charger in place of the motor controller. Every 30 minutes to two hours, I move the jumper to a different battery connection, so that all three get a part of a charge cycle. It is not optimal by any means, but it extends my range some.


Thew new stuff:

The new batteries are 20Ah,

But it is the same size and about the same wieght as the 17Ah:

The battery box opened up

and the handle on it's top is removable.

If I cut out the part where the charger connector went (an XLR), up to the bottom lip of the cover, then put an upside-down "U" of aluminum sheet in there to help restiffen the case, the box can be placed across the top of the top tube just behind the headstock, at the front of the bike.

This would put about 30 pounds up there, so it will definitely change the way it handles, and will probably take out most of the shock absorption the shock fork gives me now.

If I used this box I would put the fourth battery plus the rearmost of the three existing ones in this, moving much more weight up front to balance the bike, which would help especially when I am going to carry cargo.

However, I could also make it so these are optional batteries only used for additional range. To do this, I would keep all three existing batteries where they are, and add two new ones in this, plus a third new one in the rear triangle. All three new ones would be wired in parallel with the existing ones, as a second 36V string. A mostly-removable wire harness would need to be made that leaves extra Andersons hanging at front and back always on the bike for the other batteries to just plug into, so that I could add or remove the extra ones quickly as needed.


This would still leave me with the problem of charging them, as there would still be sets of three. However, they can be charged in pairs at least, so an automatically-rotating charger is possible but would involve heavy-duty relays/contactors or cabling (which would also be required to auto-rotate as I currently do manually, as motor power would have to flow thru some parts of the current system).

So, to charge them in pairs like this, I could simply use a timer that every 10 to 30 minutes or so would switch from the first pair to the second to the third and back to the first, switching a set of high-power relays in at least one case, though low-power could be used for the other two pairs.


For the "bottom" pair in each triplet, simply switching a low-power relay on across each one pair to engage the charger would work.

For the "top" battery in each triplet, it is harder, as they cannot directly be connected in series. First their parallel-ish connection (both positives wired together) must be changed to series (positive of one to negative of second, opposite pos/neg then connected to the charger).

That one requires a heavy duty contactor to open between the positives of each battery and the rest of the bike. Then a second (low-power) contactor to close that connects the batteries in series, and also to the charger.

The heavy-duty contactor is the issue, as it must be able to handle 100+ Amp surges during motor operation (though it does not ever have to make/break during load).

So it is much easier to go to 48V and get only one extra battery's worth of power, for now. At least until I get the Li-Ion packs finished (they are not yet started for lack of a BMS).