The Electric CB750 Project

this is one of my favorite builds/concepts, keep it up! What 3d software are you using? I use Maya and Creator for my job.
 
JoeTee said:
this is one of my favorite builds/concepts, keep it up! What 3d software are you using? I use Maya and Creator for my job.

Thanks for the kind words! I just hope I can actually get it done some day. I started laying out my wiring diagram, which is pretty intense. I won't actually be near my bike anytime soon, so I'll have plenty of time to meditate on the wiring diagram.

For the 3D work I use Rhino. I'm an industrial design student, and use it for school and work. It's nice because I can also get parts CNC milled pretty easy using the CAM plug-in.
 
I have to ask.. would it be at all feasible to get a small motor (like a go-ped motor or something) to just run an alternator or charging system of some type to charge the batteries? it would be real lightweight.. and if you get stuck out in the middle of nowhere it would be a self-contained charging system. I know this puts in into the hybrid category but 30 miles range just isnt practical IMHO. Good luck on the build, its way cool. :)
 
m in sc said:
I have to ask.. would it be at all feasible to get a small motor (like a go-ped motor or something) to just run an alternator or charging system of some type to charge the batteries? it would be real lightweight.. and if you get stuck out in the middle of nowhere it would be a self-contained charging system. I know this puts in into the hybrid category but 30 miles range just isnt practical IMHO. Good luck on the build, its way cool. :)

I see what you mean about 30 miles not being practical, but for me it's the trade-off that I've already came to terms with. I mean, for me it IS practical, just not very fun *crosses fingers for awesome new battery tech*

For now what I'd rather do is invest in the fastest onboard charger I could get, instead of the weight and complexity of making it a hybrid.

OR I could try to wedge bigger batteries in there and make the system voltage lower. But then that means more range and less speed.
 
First off, sorry to hear about the loss of your dad.

Secondly, this is a great project. I've been thinking about doing something similar-my brother flies electric rc planes, and knows the battery technology...your build provides inspiration to start designing something!

Have you seen the Hammarhead Volta? Worth googling if not-it's built out of a Royal Enfield, and uses an old style race fairing to conceal batteries and such, so that it looks classic. I imagine the aerodynamic advantage might help a little with speed and range.
 
I really like the volta, one of my favorite electric bikes on the market. The nice thing about the volta is that it runs a hub motor so you can really pack a lot of batteries into the frame, but the motor itself is like 1200 bucks. And the hubmotor is designed for higher voltages, meaning I'd need to buy atleast 8 more battery cells, which is a big cost. I'd be looking at anywhere from 2-4 thousand dollars in batteries.


I was considering a fairing from airtech streamlining too, but Ed over at elmoto.net is already almost finished with his 1979 CB750. You can check it out over here:


http://www.elmoto.net/showthread.php?981-The-quot-Juice-Cafe-quot-Racer.-From-start-to-Ton-up!-(-The-Build-Begins)


So I guess I'm going for a different thing. Showing off the batteries instead of hiding them. I want to make them feel like part of the frame. I'm concerned about fitting all 24 of them in there. If anybody has a supersport tank, I'd like to know how wide the back of the tank is, where your knees would go. I'd measure it myself if my bike wasn't 300 miles away. :(
 
Okay, so started the arduous process of whipping up a wiring diagram. Nothing is labeled yet, but it's pretty bananas. Most of the big parts are blocked in, but I still have to do all my 12V components.


Just looking at it gives me a headache.


wiringdiagramstart.jpg
 
diagramseconddraft.jpg


First real draft of the diagram. If you need a higher res version to see it well enough let me know and I'll link to one. If you see anything real bad let me know. I'm going to do more research on the throttle stuff and I'll see what I can find.

Edit: Link to full size PDF

Click Here
 
Yeah me too. I'm interning so my bike is 3 hours away from me. The only way I can work on it is taking weekend trips. That's why I'm doing all this wiring stuff now. I have plenty of time to think about that stuff nowadays.
 
Had the diagram reviewed by a few electrical engineers and had some serious errors (got to love those engineers). I've been playing in 3D and managed to squeeze an even BIGGER lithium pack in there (measuring in at 6 KWH), meaning approximately a 60 mile range! Not bad! She's a little thick in the middle but not bad. The pack weighs in at 130 pounds, 50 more than the smaller pack. A tradeoff I'm willing to make. This pack is the same size as the Brammo Enertia plus, but they're using lipo in that pack, so it's much lighter, but it's only rated for 1000 cycles (this is rated for approximately 3000 cycles).

thirddraft.jpg


70AHCALBmodel.jpg
 
I wish I had a worthwhile update. Other than buying my batteries in late June, the whole project was halted because of school. I'm interning in the fall, and trying my hardest to get a job local so I can finish the bike before winter. I have all the pieces done up in CAD, just need to build it all at this point. Here is the most recent 3D model.

70AH%252520configuration.jpg


Everything fits like a glove. The configuration is very similar in size and shape to the original motor.

I have some pictures of the batteries themselves that I'll upload soon.
 
I love this project, even tho its all conceptual at this point. I would love a fast electric moto.
 
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