The Student-Made Industrial-Strength Electric Tricycle

UPDATE: DECEMBER 10, 2010:

Well, we worked on the bike again today (after letting the kids ride the trike for two days out on the playground) and the front wheel (with hub motor) is now installed. The front forks measured exactly 100mm at the dropouts, and it was a tight fit getting the assembly properly in place, but not so tight that we had to do any modifications. In fact, it seems to be the perfect fit. I had two strong boys pull on the forks as I lowered the wheel into place (making sure the two inside washers were in the right spot) and got the wheel in. Perfect.

Then, like a dope, I tried to move the bike a few inches by lifting on the front wheel (the trike was upside down for wheel installation) and I pulled the wheel right back off.

Doh!

So, two strong kids to pull on the forks, wheel back in place, and tightened it down.

Unfortunately, one of the kids from a day earlier misplaced the right crescent wrench, so I had to tighten the nuts with a small adjustable crescent wrench, and have to find the proper wrench Monday to tighten properly.

NEXT: Monday we'll tighten it up, install the torque arm, and plug everything in.
 
Nice project.

Make sure those axle nuts are tight! Lots of hub motors have been destroyed by spinning out of the forks.
 
Great project Mike, good job. I'm sure after commuting on the trike for a while you will be addicted to electric assist like the rest of us.

In many states the electric assist bicycles can not be operated by children under 16 years of age, and all riders of electric assist bicycles must wear helmets. Apparently these caveats do not appear in Georgia law, but it might be appropriate to point this out to your students as some may end up in other states with their new passion for electric assist bicycles. :D
 
I still have to do research on the laws about kids riding electric bikes, but right now I'm on the side of caution. I'm letting them ride it by pedal power (while wearing a helmet) on the playground, but I have no intention of letting kids ride it with electric assist. I'd get in trouble for that regardless of the law.

Even though they are building it (well, 90% of the build--some things I need to do because of strength issues or safety) I can't let them ride an electric tricyle. There's no doubt in my mind that one of them would crash. They can't handle that kind of power. These are little kids (9-10 years old). Shhh, don't tell them I said they were little kids. ;)

So no fear. Kids won't ride it with electric enabled.

Also, I'll make sure those axle nuts are tight before riding. I'm one of those people who double and triple checks most things. Heck, even when I take a picture I wrap my hand through the camera strap twice before removing the camera from the bag.

I also drive defensively--hands at 10 and 2 and I stick to the speed limit.

The only time I'm reckless and out of control is at an all-you-can-eat buffet.
 
MikeFairbanks said:
Today (actually in about five minutes) I'll be showing the kids a fifteen minute film that explains what electricity is and how it's made. Here in Georgia we use coal-fired powerplants (about 60%) along with nuclear and hydroelectric plants. It's important that kids know this because at their age they just see electricity as something that comes out of the wall.
Click to expand...

The motor looks like a direct drive - no gearing inside and no freewheel. So if the motor is unplugged and the wheel turned by hand, the motor should be engaged to generate electricity. A meter or bulb across 2 of the 3 motor wires would demonstrate that.
 
MAJOR UPDATE: December 14, 2010.

Okay, the project is 14 days behind schedule, but that was mostly due to the Thanksgiving break (students had nine days off) so we're really only about five days behind schedule (not that it really matters). Our new deadline is for the Trike to be in solid functioning state by January 1st. That should be easily attainable because:

1. The assembly of the tricycle is complete.
2. The hub motor has been mounted.
3. Students today built a bracket to hold the battery to the platform (pictures to follow later today). The bracket is made of wood and is what I would call 80-90% stable (I'll tighten things up at home when I'm in my proper shop, but it's stable enough to get from the school to the house). Students cut the wood, put in light nails to tack the bracket together, and then used wood screws to hold it together properly. Then they used industrial strength velcro to hold the bracket to the platform on which the battery bag rests. The trike would have to hit a pretty big bump to knock it loose, and when I first ride it from the school to my house I'll go slow and watch that. Once at home, as mentioned, I'll give it the twice-over it deserves.

The speed controller fits in the pocket that was designed to hold it, and then we ran all the cables from the handlebars (throttle, brakes, etc.) down the frame of the bike using zipties and electrical tape (the bike is black, so that makes it blend). We had to make sure the handlebars could turn freely while at the same time keeping the wires from getting caught in the spokes, etc. That would be.....bad.

So, everything is in place and ready to go, but I have to make sure of a few things:

A. Double-check the tightness of the nuts on the front wheel (very important--and, yes, the torque arm is in place).
B. Hope for the best.


Questions (maybe some of you can help):

Should I charge up the battery now before hooking everything up? I have no idea if the battery came with a charge or not.

Stay tuned for more information and pictures.
 
Hi Mike. Yes, you should charge the batteries before your first ride. If I remember correctly, you got SLA batteries. Doesn't really matter, as you never know just what the charge level is on any new battery. For SLA, and as far as most of us are concerned, all chemistry in regular use, you should charge the battery up right after use also.
 
MikeFairbanks said:
MAJOR UPDATE: December 14, 2010.

Should I charge up the battery now before hooking everything up? I have no idea if the battery came with a charge or not.
Click to expand...
Hiya Mike,

I've just been watchin' the thread and marveling at your dedication to the students learning from this project.

As to the charging question, as Rassy said, any battery chemistry likes to be fully charged after use, but it is particularly important for SLA and if you've got a good smart charger just leave the batteries that are not in use on the charger. I'm sure Ebikekit sent you a fully charged battery pack, but a top off is always a good thing.

SLA batteries that are not fully charged and not in use will sulfate, a chemical reaction on the battery plates, that if left to continue will ruin the battery, and it won't take that terribly long to do it. Other battery chemistries are not so fickle. This means that you should always charge SLAs after use as soon as possible, and that includes taking your charger with you to school even if you have the range to go there and back because you don't want the battery at partial discharge for 6 or 8 hours each day.

SLAs also have a breakin period which means that you should do a pretty good run down on the battery pack the first 5-7 rides to give the batteries some good exercise and set them up for a good run in their lifetime. In your case, I'm guessing that means going at least 8-10 miles, then charging, on your first few rides.

Maybe I missed it, but how are you dealing with the front brake issue? This trike'll be a bit dangerous until you get a front brake on there, as it's typically the front brake that applies the most stopping power. Go real easy until that's taken care of.

Keep on pluggin'!
 
MikeFairbanks said:
Then they used industrial strength velcro to hold the bracket to the platform on which the battery bag rests. The trike would have to hit a pretty big bump to knock it loose, and when I first ride it from the school to my house I'll go slow and watch that.
Click to expand...
I've used thin and narrow velcro straps to hold stacks of dogfood bags on the back rack of DayGlo Avenger all the way home from work along the bumpy potholed roads, about 3 miles or so, and they held better than any elastic straps I've ever tried, once I got the velcro tightened down. So heavy-duty velcro straps ought to work well, especially if it is the good stuff like 3M brand (as opposed to the cheap stuff that doens't have a good cloth-weave backing).
 
I've never been able to find it in stores, but we had some stuff at a place I used to work that came as a giant roll of what looked like just the 'hook' (hard) side, but you actually used it as both sides. Between the hard hooks grabbing each other and the stellar adhesive on the back, that was the strongest stuff I have ever seen. Among other things, we used it to secure external hard drives to shelves...one time when I wasn't careful, I almost pulled the shell off of a WD MyBook trying to separate the two sides. :shock:


Great work with this project, Mike. The world needs more teachers like you.
 
Yes, I'm addicted to velcro...use it all the time.

For example, I had to tear out the tile along my bathtub to get at the plumbing under the tub (house was built too quickly, with a little less oversight on quality control than there should have been) and I didn't want to replace all the torn up tile with more tile (especially since it's a difficult job and getting the matching tile would be hard) so I build a wall of framing, beadboard, and panels that would open (cabinet doors). A nice lady at Home Depot gave me four matching cabinet doors that measured a square foot each. But rather than put them on hinges I velcroed them over the openings. How often do I actually need to work on plumbing under a bath tub? I can always put in hinges later, but for now they are flush to the cabinetry and look great. All is painted white and matches. Velcro is awesome.

THE BIKE (trike):

1. The brake thing is in progress. The front fork is pre-drilled and I'll be installing a front caliper brake. No problems there (yet), but that will be done at home next week. We're out of time with the kids....the project needs to be completed today.

2. The project WAS finished, but there was a slight problem: THE FRONT WHEEL IS ON BACKWARD. :shock: I place full blame on the students (because they aren't allowed to talk back and contradict their teacher who is always right). :roll:

Okay, not exactly: The truth is that it was my fault. I watched the instructional videos and looked at the arrow, but it was a case of left-right-clockwise-counterclockwise confusion. We all do this occasionally. We tighten what we intend to loosen or loosen what we intend to tighten, and I basically mis-read the arrow on the hub motor (I really thought I had it) and now the arrow points in the wrong direction, so the bike (when throttle is applied) wants to roll backward.

So, maybe I'll play a joke on my students today (I teach science in about two hours) and tell them that all we have to do to get the bike to roll forward instead of backward is to peel off the sticker and put it back on the right way.

That should get some laughs. Then we'll take off the wheel (and cut some zipties....arg), and reverse it, get everything plugged in, secure, and then test it.

Hopefully everything will be finished today and then the testing phase will begin.

NOTE: I will get as many photos and videos up as possible, but I keep procrastinating on getting permission. I can't put the pictures of minors online unless I have parental permission and school permission, etc., so I've been trying to take as many pictures as possible that don't show faces. I'll get a better complete package put together over the holiday break, get permission forms filled in, and then post a blog on here about it.

It's quite exciting, and the bike (trike) is looking great.

I find it hard to believe that the small little hub motor will actually pull significant weight at a decent speed. It seems so small. But we'll soon see.

Stay tuned.....
 
Another humorous note: Over the past couple days my students have taken to telling the same joke over and over, and it's really funny. Everytime there's a glitch or a fix needed, one of the students will say, "Mr. Fairbanks: Do it the manly way: use duct tape."

Not only was it funny, but it led to a short lecture about ductwork in the home and the original use of duct tape. I told them, "yes, duct tape often is the best answer. It's good stuff, but it sure is ugly." They suggested we use duct tape to hold the battery in place. It would have been quick and easy, but that's not really the best way everytime.

Plus, it's a cruel joke to hand an elementary school teacher a roll of duct tape and then tell them they aren't allowed to use it to keep students in their seats. ;)
 
Nice work mike !!!

Duct-Tape ( the handy man secret weapon ) should actually never be used on heating duct, the shiny metal stuff yes, but not the grey gummy stuff lol..

Since the wheel has to come off to fix the rotation problem, also consider the tire thread direction ! :wink:

Anxiously waiting for the video !! 8)
 
MikeFairbanks said:
I find it hard to believe that the small little hub motor will actually pull significant weight at a decent speed. It seems so small. But we'll soon see.
Click to expand...

Mike,

Make sure you unhook the "European Loop" (single black connector w/ white wire), as it will increase your speed. It is there to comply with EU laws governing assisted bikes. They are not supposed to be greater than 250W.

Believe it or not, that stock motor will get you to 30mph easy with the right lithium battery. I've never used SLA on an ebike, so I'm unsure what your results will be. I'd guess around 18-20mph after unhooking the restricter. 12-15mph with it on. Good Luck!

Also, someone mentioned earlier in the thread, but I thought it might need to be repeated, the hub motor is also a generator if spun backwards. You should be able to hook two of the phase wires up to a small light bulb or voltage meter and see the results. This would be a great lesson for your kids to see. Some on this board are actively using these hub motors as wind mill generators.
 
Also heard you say the controller fit great in a pocket. Not a good idea to have it enclosed. Better to have it exposed to some airflow. Can't wait for more pics and a dozen or so EV grins too.. :mrgreen:
 
Pics still on the way.....

UPDATE: DECEMBER 15, 2010:

The students and I took off the wheel assembly and put it back on (unfortunately, we had to kill a few zipties in the process, but thank goodness the bike is black, because electrical tape is great---I'm going to also buy this plumbing stuff that looks like electrical tape, but is rubber and sticks to itself. You stretch it, wrap it, and it fits like a glove, making it waterproof and secure).

Okay...with the wheel back on we plugged everything in and did a countdown in the classroom. I lightly pushed the throttle and the trike gently lurched forward.....SUCCESS.

Then, we plugged in the battery for a good charging, and this afternoon (in an hour or so) will give it a proper test run (I will, actually, as the kids aren't allowed to ride it under electric power). But the kids will watch and document.

To address a couple questions:

Yes, I disconnected the European suppressor loop, and all is taped up and ziptied for protection.

The controller is in the bag, but the top pocket of the bag is ventilated to allow air to flow through it.

Again, a HUGE thanks to Jason at EbikeKit.com. This kit has been so easy to install for the kids. The entire package is so well put together...I'm very impressed and highly recommend this kit. And for the record, Ebikekit.com hasn't given us anything for free and hasn't asked for an endorsement of any kind. I am more than happy to recommend their product. The same goes for Worksman Industrial Bicycles and Tricycles. Excellent product, excellent service, and wonderful enthusiasm from both companies. I'm also impressed with with Jason at Ebikekit because he sees opportunity in this project. What I mean is that he is looking into ways to fit his product to the needs of customers and is looking toward the future. He's not just running a business in which he tries to keep up, tries to get back to customers, etc., but is working hard to build the business and satisfy customer needs. Worksman did the same thing. They put in extra effort into helping our project and at no time asked for an endorsement, but I'm happy to provide it.

These two companies are exemplary, in my opinion, and when I get a few free days away from work, I plan to put out some promotional material for them to use. They deserve it.

Okay....stay tuned.....this afternoon we give the Tricycle a proper run around the track and through the straights.

Cross yer fingars, maties.
 
MAJOR UPDATE: It works!

I feel great. After the students left I took it out and tried it, then grabbed a handful of students from the after school program and gave them rides (on the back platform) around the school.

The tricycle works great....amazing! It's smooth, quiet, fast and more fun than a barrel full of monkeys. I can't believe how much fun it is. I can't wait for the rest of the students to see it in the morning. Also, the coaster brake works really well. It can almost stop on a dime. I'm still going to install a front calliper brake, of course, but this coaster brake will work for a while.

Unfortunately, it's raining outside, so we just rode it indoors, and never hit top speed, but easily went 15mph down an empty hallway. Luckily the double doors between each hall (fire doors) are wide enough to let the trike through.

For now there's only one glitch, but it has nothing to do with the motor or power: The bike bumps, almost as if the axle is bent a little, or maybe the three-speed shifter is out of whack. You can feel the bike go bump, bump, bump. I don't think it's a bent rim, but I really can't figure out what's causing it. And more than just a bump, bump sound, it's a feel as well.

It's not having a major effect (yet) but can anybody guess as to what might cause a bike to bump like that? It also feels like it might be bumping sideways a tad bit. I'm really wondering if it's in the gearing. It's a three-speed Nexus hub (in the back).

Looking back, I shouldn't have had gears put on the bike (not really necessary). But I will say this: The lower gears to make it easier to get started.

Any suggestions?

Thanks
 
Sounds like you may want to prop it up on something so you can spin each wheel. It may be as simple as airing down and re-seating the bead on a tire.
 
x88x said:
If you turn off the motor and just pedal does it still bump?
Click to expand...

Yes, it actually made the bump, bump, bump before the electric motor or components were installed.

But it doesn't bump with each rotation of the wheels, which is what makes me think it might be in the gearing. It's about every four or five turns. Isn't that strange?

Are Nexus hubs known to ever have any kind of defect that does this?
 
Mike, my trike has the Nexus 8 speed. When I first got it, it didn't seem to shift quite right, so I just adjusted it a little, but it didn't seem to help. Then one day it started clunking in some gears, and got to where it just slipped in a couple of gears.

Anyway, after getting home I went online, and found the directions for adjusing the Nexus. Turned out to be real simple and made everything work correctly.

Maybe someone on the forum already knows how to adjust the 3 speed correctly, but I'll see if it's similar to the 8 speed and get back.

Edit: Here's a short video on adjusting the 3 speed:

http://www.youtube.com/watch?v=Nx0I-4JdQ2k
 
It even does it when coasting (actually, especially when coasting). And the trike ever so slightly lurches sideways in the back (not enough to make a huge difference) but the ride is definitely not as smooth as it could be.
 
more to do with handling, but make sure both rear tires are at the same air pressure.

.

regarding the bump, lift one rear wheel and spin it by hand, then the other, if they spin true without major obvious wobble, the rims are fine.

Then, moving slowly, and leaning, run circles, both left and right, report back if the bump bump goes away in one direction.. or both.

The coaster brakes are a PITA to get right, and are often the cause of a rough riding trike.. if the drum is not perfectly round, or if the drum is not machined tight on the axle, and has 2 set screw pushing the drum to one side, it can be causing a lumpy effect as the drum makes contact with the leather band in one spot in the revolution.
 
I'm starting to think (not sure if one of you suggested it or I just thought it up) that one of the wheels might be out of allignment. If that's the case, then every few revolutions it might jump back into place. That would make sense.

NOTE: if it happens while coasting it couldn't be the gears. It must be in the wheels.

But I'm not sure how I would resolve that.

Tomorrow when I'm with the Trike again I'll see.
 
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