The Electric CB750 Project

Last day of good weather for a long time, so I went ahead and blasted the frame. I also wire brushed some parts that I had a hard time getting blasted. I then wiped it down several times with Naptha until the rag was clean and squirted some primer to keep it from flash rusting. If I need to do additional modification to the frame, I'll strip the area I need to modify.

IMG_0726.JPG


IMG_0727.JPG


Didn't have a TV so I kept refreshing the game on my phone. Go Steel!

IMG_0728.JPG


IMG_0730.JPG
 
Test fitted the motor with the finished mounts. I've VERY happy with how it came out.

Mockup with the tail and tank.

IMG_0731.JPG


IMG_0732.JPG


Aforementioned motor mount.

IMG_0733.JPG


IMG_0734.JPG


And finally got this bastard out. Had to make a wrench out of a piece of bar stock and 2 5mm bolts.

IMG_0736.JPG
 
Started to mock up battery mounts in Foam-core Aided Design. I'm pretty sure I have my final design, I just need to refine it, and make sure I have my bend allowance calculated correctly. I want to be able to remove each battery pack without taking everything apart, and I think I'll be able to achieve that.

Here's the main tray. Ignore the flaps that hang over the frame really far, they'll be trimmed. Those flaps fasten to the original frame mounts.

IMG_0737.JPG


Here's with the batteries in place. There's a small pack that goes under the big pack, but I can't mock that up right now.

IMG_0738.JPG


IMG_0739.JPG


Had to put the tank and tail on to check proportions.

IMG_0740.JPG
 
This bike is really starting to look badass! I'm curious about how it will handle, though. What is the total weight of your batteries compared to the stock 750 motor?
 
The battery pack weighs about 122 pounds, so it should be plenty less than stock. I did weight estimations several months back, I'll see if I can find them.
 
+1. This is a great project.

While the batteries may weigh a good bit less than the stock motor, the only concern I would have is the weight distribution. Don't get me wrong, I don't know squat about "proper" distribution, just wanted to mention the change.
 
Yeah, there's no way of really telling until it's all back together, but I tried to mirror the original motor location as much as I could, so hopefully the weight distribution won't negatively affect handling.
 
wow just seen this and am very impressed, looking forward to more updates!
good luck with the build
Mark.
 
This project kicks all kinds of ass! One question though, are you going to run 2 of those clamps around the motor itself? I'd be worried about torque flex with only one holding it. Cant wait to see this thing move under it's own power.
 
Jewbacca said:
This project kicks all kinds of ass! One question though, are you going to run 2 of those clamps around the motor itself? I'd be worried about torque flex with only one holding it. Cant wait to see this thing move under it's own power.
Click to expand...

I based the design of the clamp on another build. I talked to the builder, Noah, about this and he said that he's been just fine with one big clamp. I over-engineered my clamp a bit, making it out of 3/4" aluminum compared to the 1/2" of Noah's clamp. If I have any issues I still have the CNC programmed to make another.

Thanks for all the kind words guys! I've got access to all of this equipment until mid December, so I better get a lot done.
 
Taped off the terminals, this is only half of them right here.

IMG_0781.JPG


IMG_0782.JPG


Satin black.

IMG_0783.JPG


The vents also have to be taped off, so we made a die on the lathe and punched some tape to perfectly mask off the vents. Saved a lot of time.

IMG_0785.JPG
 
Maybe I missed it but what position with Crown did you or are you interning for? Something engineering I presume with the electrical and Inventor? knowledge...

This build looks really awesome so far. I plan to follow in your footsteps eventually. Keep up the great work!
 
SeekingZero said:
Maybe I missed it but what position with Crown did you or are you interning for? Something engineering I presume with the electrical and Inventor? knowledge...

This build looks really awesome so far. I plan to follow in your footsteps eventually. Keep up the great work!
Click to expand...

Actually I'm just a lowly product designer. I do all of my modeling in Rhino, which is less engineering based than Inventor. The electrical I spend months learning, lots of looking at other people's diagrams and reading component documentation.

Thanks for the kind words!
 
Big Rich said:
+1. This is a great project.

While the batteries may weigh a good bit less than the stock motor, the only concern I would have is the weight distribution. Don't get me wrong, I don't know squat about "proper" distribution, just wanted to mention the change.
Click to expand...

Having pushed my buddies 76 CB750 around the garage at bike night enough times and ridden it a few I can tell you that they're generally front heavy pigs to begin with so this should be an improvement. :p
 
You're a product designer? I have a good buddy that does that, well he is a industrial designer(not sure how close those are..).. He has some pretty cool stuff. A lot of it is in Rhino too but some of it he made prototypes.. He also does steel artwork as well..

His website is http://l-e-it.com/
 
Sorry for the crappy cell-phone pictures, but I got the big pack together with new straps and painted compression plates.

IMG_20111120_185348.jpg
 
Is that wired together already? Looks massive already. How is the array going to be wired together(series/parallel)?
 
Nah, no wiring yet. Those are actually 3 packs of 6 right now. It measures about 16 inches wide by 14 inches tall in that configuration. Each cell is 3.2 volts and 60AH (low voltage, high capacity), and they'll be wired in series to achieve my final voltage. There are also two more small packs of 3, one that tucks under this one in the frame, and one that goes where the carbs go. I'm determining right now if I want to make each of those packs of 6 a separate thing, so I can pull a single pack of 6 out if I need to service them for any reason. Taking out the whole pack of 18 is pretty tough, but six is easy for a single person.
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light

    • Spread the Love

    Back
    Top Bottom