Electric Bikes - Engineering student needs suggestions: Solar-Electric Trike!

Are you guys sure you are engineering students?
Was that really necessary? Particularly since Simplecj already correct your misunderstanding earlier in the thread (last time I was a t fault).


I suggest that you ... spend more time reading sites like www.batteryuniversity.com (http://www.batteryuniversity.com)
Then allow me to suggest reading www.a123systems.com/technology/power (http://www.a123systems.com/technology/power). Be sure to click "fast charging capability".

Um, SeizeTech... again, you are another person who hasn't read the whole thread and doesn't realize that I'm not talking about just any lithium cells.

I have A123 M1 cells that CAN take way more charge than most other cells.
RATED: 10A to 3.6V CCCV, 15 min (for single cell; parallel cells multiply, 6 in parallel can take 60A for a 15 min quick-charge, but good luck finding a 60A power source)

Check it out and quit being cynical for no reason...
http://a123systems.textdriven.com/product/pdf/1/ANR26650M1_Datasheet_AUGUST_2008.pdf

EDIT: They also have M1Ultra cells that can charge in 5 minutes!!!!

To those of you who have posted links to other resources... I have been in finals week and too busy to do much research and with the holidays coming up I may be slow to respond.

Thank you for all your input, this is the wonderful thing about forums. Accelerated research and discussion with people who know (and sometimes only think they know) what they're talking about. I really appreciate you all taking the time to contribute!

I will probably post a few times over the break, then when spring semester kicks in gear I'll be all over this like cheese on pizza!!

(I will eventually start a new thread with a reformulated proposal when I nail down a few ideas and possible components)

Happy Holidays!

I have A123 M1 cells that CAN take way more charge than most other cells.
RATED: 10A to 3.6V CCCV, 15 min (for single cell; parallel cells multiply, 6 in parallel can take 60A for a 15 min quick-charge, but good luck finding a 60A power source)

EDIT: They also have M1Ultra cells that can charge in 5 minutes!!!!

I run a set of 80 - A123's cells, broken into sets of 4 cells (12 volts), then wired into 48 volts for a 16s5p pack, in my trike.

They are great cells. Mine sat in a shed all last winter, starting with a resting charge of 53.4V, they were checked every month for the next 6 months for voltage. Always 53.4V. They didn't even drop a .1V over 6 months of sitting.

I'm sure you know, but charging these cells at 15 minute, 60A rates, probably takes some specialized charging stuff and thermistors on every cell.

I use 4 - "12v" smart chargers for LiFepo4's to charge at the "12V pack" level at 1.8A. Usually takes about 3 hours from 12V ("dead") to 15.4V termination. Batteries remain ice cold.

Those batteries and my chyrs 5303 motor with 4840 controller, accelerates me and the trike ( 350+lbs) at a pretty good clip up my 12% driveway, from a dead stop, with no pedaling. Each of my 12V packs is fused at 40A. None have ever blown so far, and I've climbed some pretty long and steep hills at full throttle.

I know, what a rat's nest of wiring. Just a proto. :)

Full voltage on 4 in series, would be 13.2v, 14.4v peak charge level (you said 15.4v?)

So with a 48v configuration, you'd actually be at a nominal voltage of 52.8V (16 cells in series or four of your packs).

What is your range with the 5303 and the 4840 controller on a single charge??

I only have about 66 good cells so I was going to shoot for a 11s6p configuration (36.2v nominal 13.2Ahr)

I'm very interested to hear about another A123 powered trike!

Full voltage on 4 in series, would be 13.2v, 14.4v peak charge level (you said 15.4v?)

So with a 48v configuration, you'd actually be at a nominal voltage of 52.8V (16 cells in series or four of your packs).

What is your range with the 5303 and the 4840 controller on a single charge??

My chargers terminate at 62V, then if left to sit, the 16 series string will rest at 53.4V for months. They are all new, so they may settle down to a lower resting voltage after a few cycles.

I bought 9 DeWalt packs off Ebay a couple years ago. Had to threaten one seller for my six packs. Average price of $9/cell. Bought one DeWalt charger to make sure each pack started fully charged. 3 out of 9 packs wouldn't charge, found 6 cells out of 90 were bad (.245V) and couldn't be revived. The ones that are good...are great.

The trike's maiden voyage was with only half it's packs, about 5ah, up to Mom's house about 5 miles away and 500 foot gradual altitude gain. Made one run to top speed of 36mph for a moment, then ran gently at about 15mph for rest of trip. The entire trip was made without pedaling, as they're not hooked up yet. Made the distance fine, but as I was getting close to 4 1/2 miles, the famous A123 dump came on like I blew a fuse. I let it sit for 10 minutes and was able to limp the last 1/2 mile in, so there is some reserve.

Figure I had about a 250wh pack, that's 50 watt hours/mile. Up to 500wh now.

The trike is about 9 feet long, welded up out of 1 1/4 mild steel, so I could hand bend it with a big electrical conduit bender with a 10 foot handle. Width is 32" max to fit through 36" doors. The back wheels are cambered out and you sit pretty low, but it is still fairly tippy, but not too bad, and it will definitely tip over long before the back wheels slide. I'd rake the front wheel forward more to slow the turning response. You could take a 90 degree street turn at about normal car speed, 15 to 20 mph. Has full suspension and front disk brake. Stops very well.

This was just to see how trikes feel, to see if I want to build the next one...a fully enclosed one, with lights, heat, and music, because I am just that big a dork.

Wow... you're overcharging your cells a bit! Your peak charge on those cells should not exceed 3.6v or 57.6V for your case. That's why you have the higher resting voltage. These cells are pretty specific on their voltages. We got a few dozen cells back from the testing facility that were overcharged and resting at between 3.4 and 3.62v. It's not really a horrible thing, but you get very little energy going over voltage and if repeated can reduce the life of your cells. As soon as I had isolated the overcharged cells I discharged them 10 at a time (in a parallel charging rack I built) using a set of fog lights for the load. Best to get them undervoltage ASAP, the longer they sit like that the more likelihood of damage. Of course A123's ARE tough cells, but you gotta treat them right to get that 1000+ cycles out of them!

At 62V, you're charging them to about 3.8V per cell and they're settling down to 3.34v each.
Are you using a CCCV charger? I have one that specifically charges A123's as well as several other battery types and it goes CC to 3.6v then CV and slowly turns down the amperage from 5A down to 0, controlled by a specific algorithm. My RC pack, 3s2p (from a DeWalt pack), charges in about an hour using the 5A setting.

A123's require a good CCCV charger to maintain their rated life and capacity. Overcharging them is not a good idea.

How did you try to revive them? A low current 3.3v power source either from a lab power supply or a modified computer power supply (like mine), can bring them up to proper voltages. Most smart chargers will not recognize a cell if it's under 2V. That's how I revived probably over 150 cells that we got that where drained to near 0 and they all took a charge and tested good.

I know what you're talking about with the "dump". My RC car goes like a bat out of hell for about a half hour then suddenly within about 10 seconds it goes from tearing around to done. Not all bad, but you definitely want an accurate way to monitor battery levels, especially if you don't have your pedals hooked up!

Can you post some pics??

My camera sucks.

You know what would look sweet on there... a good motorcycle trunk! They run between $100 and $200 on ebay. That's what I'm thinking of putting on mine. That way it looks nice, you can lock it, and they even make some that have a quick detach mount (also lockable) and you can pick it up like a suit case!

Of course they aren't as long as your platform and I'm guessing you have your electronics mounted under the seat. The bigger trunks are about 22" long 18" wide and 16" tall. I figure I can mount that with my batteries, charger and controller and just mount plugs in the side so it's all one quick disconnect unit. They even have little ignition keys you can mount in it so you can turn it on/off by key. Electronics and batteries are expensive, I'm thinking about protection. A lockable trunk of some sort.

BTW... I like your use of the bike frame parts for the back wheels and your suspension! Very creative! You probably wish it were easier to bend and weld aluminum huh? It's gotta be a bit on the heavy side being mostly steel pipe...

BTW... I like your use of the bike frame parts for the back wheels and your suspension! Very creative! You probably wish it were easier to bend and weld aluminum huh? It's gotta be a bit on the heavy side being mostly steel pipe...

Thanks, tried to come up with a design using the most off-the-shelf parts and the least amount of modifying. Next frame is 3/4" thin wall cromoly. May look something like this....if you can make it out.

Currently, I have a big, waterproof, lockable, Contico container I use as a trunk.

The upside to your rear wheel design is that you can tilt the wheels in to improve stability, especially if you can hit speeds of 36mph! But you're only driving a single rear wheel, does that effect handling at all?

The trike I'm getting has a solid rear axle and the chain drives at the center of the axle to both tires. Once I get the bike (next week) I'm going to try to determine if a regular BCM motor will work on it. Only problem is that I'll have to get the freewheel gear that mounts on the motor, which is almost half as much as a good motor and really adds to the expense. Then again, it's still comparable to a hub system and the BCM motors get better efficiency as James1986 pointed out (95% vs 80% with hubs). But using the BCM motor also adds quite a bit of complexity to the design. I just need to see the trike... I'm so impatient!

Edit: Anyone know how people rig up those BCM motors so that your peddles don't turn with the motor?? That's actually my BIGGEST problem with that style motor. The freewheel on the motor can prevent turning the motor when you're just peddling, but what about the reverse? The motor will spin the peddles right?

I guess I could possibly mount a second sprocket off to the side of the existing one and have it on it's own chain, but I was reading that if it's not driving to the center of the axle that the bearings get torqued unevenly and wear out faster (or something like that). Perhaps better bearings? Maybe it's not that critical... I don't know.

http://ecx.images-amazon.com/images/I/51KcxB%2BO-wL._Schwinn%20Meridian%20Adult%2026-Inch%203-Wheel%20Bike_.jpg

Thanks, tried to come up with a design using the most off-the-shelf parts and the least amount of modifying. Next frame is 3/4" thin wall cromoly. May look something like this....if you can make it out.

Currently, I have a big, waterproof, lockable, Contico container I use as a trunk.




wernmax im working on a rear trailer made from a old dolly and a rubbermaid container. how good does it ride in heavy traffic? do drivers get around you allright? also the tires do thay bounce around allot?

im also going to add a solar panel on the lid and make room for a spare battery and dc inverter for the long rides.

cheers.

Was that really necessary? Particularly since Simplecj already correct your misunderstanding earlier in the thread (last time I was a t fault).


Then allow me to suggest reading www.a123systems.com/technology/power (http://www.a123systems.com/technology/power). Be sure to click "fast charging capability".

Well, what can I say? When you are right, you are right.

That wasn't necessary. My apologies to everyone.

I wanted my comment to be received as a friendly jab, not an insult. I promise to try and use something like a smiling emoticon next time I make an attempt at that type of humor.

BTW, I am impressed with the fast charging capability, but I am having difficulty interpreting the graph. Does the battery reach 90% really quickly, then takes even longer to reach 100%, or does it reach 100% fairly early on that graph?

Sorry, but there is no text to go with that graph, and traditional knowledge from somewhere like batteryuniversity.com usually states that a quick charged battery pack requires additional time for balancing the cells, which often negates the time savings of the quick charge.

rgds
Tyler

Also, if you want to truly charge the cells in 10 minutes, you are going to have to change the method of approach to the topping up phase of the charge.

Once a battery reaches a certain capacity, in the case of the A123 it looks like 90%, the charger usually switches from a constant current to a constant voltage. The moment you switch to a constant voltage, you will be fighting the clock. The topping up phase of a charge cycle is inherently something that doesn't fit into the scheme of things when you start to look at fast charging.

You know what would look sweet on there... a good motorcycle trunk! They run between $100 and $200 on ebay. That's what I'm thinking of putting on mine. That way it looks nice, you can lock it, and they even make some that have a quick detach mount (also lockable) and you can pick it up like a suit case!

Of course they aren't as long as your platform and I'm guessing you have your electronics mounted under the seat. The bigger trunks are about 22" long 18" wide and 16" tall. I figure I can mount that with my batteries, charger and controller and just mount plugs in the side so it's all one quick disconnect unit. They even have little ignition keys you can mount in it so you can turn it on/off by key. Electronics and batteries are expensive, I'm thinking about protection. A lockable trunk of some sort.

BTW... I like your use of the bike frame parts for the back wheels and your suspension! Very creative! You probably wish it were easier to bend and weld aluminum huh? It's gotta be a bit on the heavy side being mostly steel pipe...

many boat plans use plywood that is covered with a skin of fiberglass and resin. the plywood allows for easy construction and a solid shape for the fiberglass cloth to stretch over.

also, you might want to investigate using ABS plastic sheets and tubing, where you can use a solvent bond to weld the peices together. If you search for 'compucars MEK' you might find a website that for automotive hobbyists that like to do custom touch screen installs into their dashboard. They ussually take the bezel from the touch screen and mold it into the dashboard using solvent bonding and sometimes abs shavings in a solvent as a paste.

wernmax im working on a rear trailer made from a old dolly and a rubbermaid container. how good does it ride in heavy traffic? do drivers get around you allright? also the tires do thay bounce around allot?

im also going to add a solar panel on the lid and make room for a spare battery and dc inverter for the long rides.

cheers.

Made mine from a dolly too, but cut and rewelded the axle a little further up the frame. I haven't noticed much bouncing, but it is a little top heavy and tips over somewhat easy, so I'd be afraid to mount expensive solar cells on the lid unless you provide for that possibility. The trailer is pretty heavy, and the little wheel bearings aren't real efficient rollers, but everything I need is within a mile. It handles a couple hundred pounds of load easily.

I seldom get into traffic, but when I have, the trailer and bike must look more substantial than just a bike, so it seems cars give me even more leeway.

I made the bike part of the hitch out of conduit. Welded on a heavy angle bracket, and a holed clevis pin on that to receive a piece of gate hardware, a round eye bolt. The eye bolt is just inserted through a hole in the dolly frame, and double nutted so it turns.

Again, my 2 megapixel camera doesn't do macro worth a darn. Time for an update.

Also, if you want to truly charge the cells in 10 minutes, you are going to have to change the method of approach to the topping up phase of the charge.

Once a battery reaches a certain capacity, in the case of the A123 it looks like 90%, the charger usually switches from a constant current to a constant voltage. The moment you switch to a constant voltage, you will be fighting the clock. The topping up phase of a charge cycle is inherently something that doesn't fit into the scheme of things when you start to look at fast charging.

My hobby charger does a fast charge CCCV, it just reduces the CV time by about half, but you're right. That first 90% is the fastest and may be all you need in the "need a charge quick" situation. I'm pretty sure it wouldn't hurt the batteries as long as you did the occasional top-up charge and that may not even be needed with these cells. You could always do it the same way, just have two modes, quick charge and normal charge. Also, I believe the 15 minute rating is for 100% charged. My 10.1v 4.6Ahr (3s2p) RC pack takes almost exactly an hour to charge at a 5A max normal charging algorithm. It takes about a half hour to discharge at around 20A-60A (yes my RC is a high powered brushless monster).

Hi Simplecj,

Im pretty sure you can get some freewheel bearings that fit into the pedals.

Failing that you could always buy an appropriate sized wrench, fit it to the axle, and glue a pedal on the other end?:roflmao2:

James

Um... ok James... I think I like the idea of a second chain better than a glued on pedal. I don't think they make freewheel bearings for the pedal sprockets. And glue... haha very funny. :lol:

I think you are right though about not using a hub motor. Even with the increased complexity, the gain in efficiency, lower weight, and lower cost of the regular motors are enough to make it worth trying. I mean properly designing electric powered vehicles is all about efficiency, right?

As far as the regen braking... well that would be pretty complicated I think to incorporate. I could forgo the freewheel sprocket, but I don't really know much about how regen works and if it is possible with just any motor. Also, what if you want to coast and not regen? It just seems like a very complex problem especially when regen is said to only be about 20% efficient. Without some pretty sophisticated electronics to control the regen, is it worth it??

I also appreciate your point about making a marketable solar charging system. That was one thing our junior design professor stressed, that any design process should look to how it could be marketed and sold. I don't know if I could really fit enough solar panels or super caps on a small bike trailer, let alone make it affordable to build. Also, not all ebikes are capable of a "quick dump" charge. Most would need several hours at least to get a full charge. And, who would want to leave an expensive peice of equipment like that just sitting on the side of the road?

Wernmax: How did you assemble your battery packs? Did you just leave the tabs on the cells and solder to that? That's what I did for my RC packs, but my loose cells don't have tabs on them, so I'm looking into either building a resistance welder or making another trek to Boulder to use their equipment again...

Here's a pic of the packs we assembled for my junior design. We built 35 of these 4s8p modules! The design only required 32, I wish we still had the extra 3 modules that we built. It would solve a lot of my problems. I might send the electric motorcycle guy an email asking him if I could get them back... I don't know though if he'll go for it.

Just went and picked up the trike!!! :thumb: It's a lot lighter than I expected. Other than a bit awkward, the box wasn't too heavy to handle by myself.

That's one of the reasons I think this trike will be a good candidate for LEV, because it's got the L for lightweight aluminum frame!! ;)

My shop is pretty small so I had to get a cover for my motorcycle so I could stick it outside for the winter. Haven't got it registered yet cause I barely finished restoring it a few weeks ago... here's a pic. 1981 Kawasaki 305CSR, almost as old as me!

Here's another pick of one of my earlier projects. Can you guess what it was before I tore it apart??

Well... off to the shop to put it all together.

Here's a pic of my 10 cell charging rack hooked up to my hobby charger. Two or three similar units would be enough to properly charge my pack. They only do up to 6 series packs, but they can do it at 5A and you can wire it up to balance charge each individual parallel set in the pack.

For the size of my pack, I'm guessing I'd get a full charge in about 3 hours using these hobby chargers. Bad thing is that they're about $100 each for the cheap ones, but at least they're programmed to do A123 cells!

Wernmax: Next time you store your cells for the winter, you should only charge them to 80% capacity. That is the specified storage limit for these cells to ensure shelf life.

As you can see I've done A LOT of work with these cells and that include a semester's worth of research on just how far we could push them. My project was a battery pack designed for an electric upright 200hp (150KW) motorcycle running an AC Propulsion motor system, the same system they use in the Tesla Roadster! The person we were working for is currently building the bike an hopes to break the land-speed record for an upright electric motorcycle next summer. He's shooting for 200mph and we're fairly sure he can do it. The pack we designed was a 423V 128s8p (18.4 Ahr) configuration. For the 200mph mark, he would use about half to three quarters of the energy in the pack within less than 3 minutes. We're figuring on at about 400A at peak power, or about 50A per cell with 8 in parallel.

OK!!! SO, I got the bike together and now.. well to say the least, my project has taken a radical new direction!

After assembling the trike, I rode it around the yard. I have to say that the stability questions were correct. This bike is not very stable and probably not safe over 10mph.

That said, I found myself taking the seat off, turning the handlebars around and sitting on the basket mounts. The increased stability was considerable!

I am now thinking of designing extension brackets to move the rear assembly about a foot backwards. I can model them using Autodesk Inventor and with the help of my buddy, a freshly graduated CAD/CAM major, and our schools resident machinist, I can get them machined to fit perfectly.

Extending the rear will require more than just two extension brackets so I'm thinking I can mount two long tie bars that go across the basket mount bars and attach to the two upper supports going to the seat post. Then the seat and trunk will mount on top of the tie bars. The motor could be mounted below that in the rear. I will need to determine the proper distance from the pedals to the seat in order to make sure my weight is in front of the rear axle to keep some weight on the front tire. I'm guessing a foot will be enough.

Does anyone know the proper distance from your hip to the center of the pedal crank? I'm sure I can figure out what feels comfortable, I'm just wondering if there's a standard distance or range.

The motor could easily be ran to a freewheel sprocket mounted next to the main drive sprocket on the rear axle!

Also, I said before that the axle drives both wheels. It does turn the entire axle, but the left side wheel is mounted on bearings so it is not driven. I now understand that the reason for that is tire wear from turning. Without a differential the tires would get tore up quickly.

As for steering... I would probably rig some linkage up similar to what Wernmax has on his homemade trike.

What do you think?

a good starting position is place you heel on the pedal with a straight leg. so that when you place the ball of the foot on the pedal, you knee is not locked, yet the leg is reasonably straight. This is your course addjustment.

then test drive it To fine tune your seat adjustment...

..if you find your ass having to swing, you are probably too far from your pedals.

if you find you are unable to deliver much power to your pedals then you might not be high enough.

Personally, I think I am not describing the fine adjustment well. But, you can often find the best fine adjustment through preference.

Hey Simplecj,

The way my friend did it last year was to incorporate an extra gear on the normal set, which you obviously switch to, to enable regen. That way he had freewheel and regen capability! Bit annoying to switch it on every time you want to brake, but for going down hills at a reasonable speed, it regained quite a bit of energy.

For some circuit designs, and plenty of help in this area check out the endless sphere forums!

Also, if you include suitable capacator into the equation before sending the regen to the batteries, you will reclaim up to 100% of the energy (minus efficiency losses).

James

Made mine from a dolly too, but cut and rewelded the axle a little further up the frame. I haven't noticed much bouncing, but it is a little top heavy and tips over somewhat easy, so I'd be afraid to mount expensive solar cells on the lid unless you provide for that possibility. The trailer is pretty heavy, and the little wheel bearings aren't real efficient rollers, but everything I need is within a mile. It handles a couple hundred pounds of load easily.

I seldom get into traffic, but when I have, the trailer and bike must look more substantial than just a bike, so it seems cars give me even more leeway.

I made the bike part of the hitch out of conduit. Welded on a heavy angle bracket, and a holed clevis pin on that to receive a piece of gate hardware, a round eye bolt. The eye bolt is just inserted through a hole in the dolly frame, and double nutted so it turns.

Again, my 2 megapixel camera doesn't do macro worth a darn. Time for an update.


your right i did find it top heavy. im going for a low profile trailer all i need is room for electronics and batterys and solar panel. i will also try moving the axle to the center.

thanks

Edit: Anyone know how people rig up those BCM motors so that your peddles don't turn with the motor?? That's actually my BIGGEST problem with that style motor. The freewheel on the motor can prevent turning the motor when you're just peddling, but what about the reverse? The motor will spin the peddles right?
http://ecx.images-amazon.com/images/I/51KcxB%2BO-wL._Schwinn%20Meridian%20Adult%2026-Inch%203-Wheel%20Bike_.jpg

This may be what you are looking for: http://www.cyclone-usa.com/store.php?action=show_detail&crn=203&rn=313

You may have to buy the chainwheel from them as well or adapt this freewheel to yours.

Thanks... I actually think I'm going to mount the motor at the rear with a freewheel sprocket on the axle next to the peddle driven sprocket. I'm working on modeling the bike in inventor to design extention brackets as well as motor, seat and trunk mounting.

That's a great idea, the downside in some circumstances is the motor then doesn't get to share the mechanical advantage of the gears. I'm not sure if you even planned on doing that in the first place.

They do make freewheel sprockets that are designed to be mounted on the left side if you run out of room on the right.

I have solved my batter welding problem!!! :thumb:

Ahh...very cool.

I haven't had need to do that yet, as you guessed I had tabs already on my packs that I cut then curled over and soldered 10 ga wires to.

Ok, so I got a bunch of stuff now...

I bought a 10A iCharger with graphing capabilities through a USB connection. Tested every single cell I had and grouped into groups of 8 cells with similar capacities. I ended up with 9 packs of A123 cells, but the bottom 1 or 2 packs are pretty crappy. I'm trying to figure out what will happen when these lower capacity packs go flat before the others. They will all be connected in parallel, but have their own connectors for individual balance charging.

http://www.progressiverc.com/1010B+%20-%20Layout%20View.jpg

I got all the packs glued together, got my wire, shrink wrap and cut my battery tabs out. Just waiting on my zinc solder and flux for experimenting with soldering to the positive terminal because I don't really trust the welds I'm getting on that end. I also have balancing and power connectors coming soon so I'll be able to finish assembling the individual packs and move on to modifying the motorcycle trunk to house the packs and other electrical stuff.

Spent some time getting the spot welder worked over so everything's a bit cleaner, especially the wiring.

I got a lockable/removable motorcycle trunk. Fits perfect between the rear wheels and looks alright too.

I just purchased the Cyclone 500W Brushless motor kit. I'm going to try mounting it with the included mount inline with the crank chain as they recommend. The kit also comes with the freewheel crank adapter and a wider crank shaft to fit around the motor.

http://www.cyclone-usa.com/sc_images/products/291_image.gif

I was toying with the idea of putting a multi gear sprocket on the rear with a derailer system, but then I stumbled across something even better!!

Shimano Nexus 3 Speed Trike Hub with internal gearing, a direct fit for my trike!! :thumb:
http://images.nitrosell.com/product_images/1/94//00518.JPG
Now I can have 3 speeds and get better efficiency from the motor! Ordered it yesterday, should be coming soon.

Everything seems to be comming together well. Main issue now is getting my extension brackets and steering brackets machined. My buddy said he'll be in the college's machine shop working on some stuff and that he could do it for me... if I pay him... $100 for four parts? Sounds reasonable for a friend right??

Hi Cj,

Glad to hear everything is coming along!

How are you going to get better efficiency out of the motor with the hub gears? Aren't you using a hub motor?

You could probably machine 4 parts yourself in about an hour or two, plus it would be good experience for yourself as when you get to industry, unless you are in a reasonably sized company, you will be doing it yourself anyways.

How much was your charger?

James

I'm not using a hub motor anymore. Look at my post, I purchased a 500W Cyclone motor kit. Rated peak efficiency near 90% while most hubs are topping out around 80%, the motor comes with a 9:1 freewheeling drive reduction gear box for better torque. Add the Nexus 3 speed hub and I should be able to maximize efficiency. Well... as good I can without adding more gears! Cyclone claims a 45 mile range with this motor, moderate weight, moderate speeds (12-15mph) and a 20Ah 24V lithium pack! I'll be more than happy to get a 30 mile range on my trike!

I am a certified machinist (manual work mostly), but the extension brackets have somewhat complicated pockets in them for the bike mounts to fit into. I could attempt to do this manually on my dad's crappy mill, but I am certain the results would be less than ideal. My buddy just graduated with a CAD/CAM degree, works at MetalCraft, and is in good with the school's machinist who just asked him if he'd come in and do some work for him and won't care if he uses the machines to do my parts while he's at it.

I already have the brackets 3D modeled in Inventor, just need to transfer that to MasterCam and program the tool paths. Then it's just a matter of my friend clamping the stock and running the programs... and the parts will come out very nice from a 5 axis CNC mill!

I got the charger for about $190 shipped from: http://www.progressiverc.com/1010B+.html

To charge my 8s packs at the full 10A rating, I had to get a 15V 25A power supply... found a good Pyramid lab supply for about $100 that maxes out right where I need it!

Just updated my expense sheet... already up to about $2030... and for those of you who think I could of done this cheaper... keep that to yourselves!! I've put alot into my battery testing and assembly... about $700... then again, how much do you think a 20Ah A123 pack would cost new??? 76 cells at about $15 each...

Update:

I've got all my battery packs assembled.

The removable trunk/battery storage is pretty much done.

I also got the motor mounted with the chain, extended peddle crank and Nexus 3 speed hub.

I'm waiting on the machine shop to get my extension and steering brackets done, but it sounds like I could be waiting several weeks for that, so I'm about stuck.

What I need to focus on now it building the headset that will mount into the seat post with an offset bracket like in a picture I posted a few pages back.

Here's some updated pics of building the batteries, trunk and the mounted motor etc...

SOOO>.... Today I put the rest of the doo-dads on the bike!

I installed the shifter for the hub, the cycle analyst, and the connector and mount for the battery compartment.

Runs excellent with all batteries connected, was peaking up around 800W, 500W average full load. It does ok with electric only, but if you pedal with it, that's when it accelerates very fast! I clocked my top speed at about 23mph!! :thumb: Of course there are people who will say that's too fast for a trike, but really as long as you only use 2nd and 3rd gear on straightaways you should be fine. Also, when I get the frame extended and move the CG down it should improve stability greatly. For now I'll just make sure I slow way down before attempting to turn. I also will probably gear it down a bit in order to get a bit more torque from the motor. With an estimated load of 300 pounds, I probably need the torque!

The Nexus hub worked great, but I had some problems getting it set right. I tried to use the little window on the hub end of the cable to adjust it, but I couldn't get it line up with anything. So I resorted to just tipping it on its side and adjusting it till I had all 3 gears shifting properly. On the road it performed very nicely. I could shift it under load with almost no noticeable lag in the shift, but once or twice I heard something pop, so I'm guessing it's best not to shift while still accelerating.

Another problem I had was that my handlebars are too short before the bend, so I don't have enough room to mount the controls properly and have to hold onto just the end of the bars practically. I cut the stock bar down cause I want it smaller for when I move it back, but I'm going to have to get a different bar that's not bent that far out.

I only have the front brake shoes to stop me, but the stock brakes seem to be plenty adequate, I can always add a disk brake to the front if I want to. Also, braking on the rear at higher speeds could be dangerous since only one wheel is locked to the axle and could pull you to one side if you were on loose or slippery ground. The extended frame would probably counter some of that force though, so I may still consider a disc brake on the rear axle, but that's near the end of my list of things to do.

If you look at the picture, imagine the rear assembly shifted back by 14 inches, the seat moved down to the trunk level and the handlebars mounted on the seat post like in this picture, but offset towards the front... http://www.lightfootcycles.com/txlsteer.jpg

That's one of my biggest issues right now is designing and building that offset headset for the steering extension. Like in that pic, I'm going to use ball joints and connecting rods with custom brackets, that is, I'm doing a dual-link steering set-up. Not that it's necessary, but that I think it will look nicer that just on one side. I have the headset bearings and caps, I just need to figure out what size pipes I need and where and what to thread them to. Also, how to connect the headset to the pipe that will slide into the seat post. This should be an interesting challenge...

Here's my efficiency ratings as of 3-24