electrifying a cannondale bad boy 700

e-cannon

100 mW
Joined
Oct 5, 2009
Messages
45
Hi there.
Sorry my English I am from Switzerland.
I just finished my e-bike project. It did last longer than expected, but now it is finished and riding my bike really rocks.
The concept:
I just wanted a bike of my choice to be electrified. I did not want a front hub so I had to find another place for the battery than a rear rack because of the improper weight distribution. And I did not want to see much of the wiring. So the battery had to be somewhere in the bicycle frame. And in a case. I decided to buy an ezee-kit from http://www.ebikes.ca and so I did. Thanks to Justin at this place for all the answering on my noob-questions about electricity.
Then I bought a cannondale bad boy:
01_cannondale_bad_boy.jpg

Before the bicycle was assembled by my dealer (I had to wait about 2 weeks) I just made an exact drawing from the frame geometry in my dealers shop. Cannondale would not give me a CAD drawing of the frame geometry. I asked.02_drawing_from_frame.jpg

Then I made an 1:1 Autocad drawing of the project (I am an architect. So no problems here):
03_autocad.jpg

Of course I verified the design in 3dsmax (what we do with all our projects). I had a low poly 3d model of another bike which I adapted to the original frame geometry. Good enough for an impression.
04_3dsmax.jpg

I then spent some time in fibreglass forums until I thought I knew enough. Then I started with modeling the form out of styrofoam (mainly used to insulate buildings).
05_form1.jpg

Some priming & grinding:
View attachment 4

Epoxy over it so the separating agent would not destroy the styrofoam. Once again verifying the form...
07_form3_epoxy.jpg

I placed those strong inserts where the case will be connected to the bicycle frame. Just to be sure.
08_form4_inserts.jpg

Put some separating agent on the thing. Ready to laminate:
View attachment 1

Laminating in process. I do not want to do this again. It's so toxic (endless-sphere?).
10_laminating.jpg
 
After about 24 hours: Cutting out. First contact with this really strong material. You need tools for metal editing to deal with fibreglass.
11_cutting_opening.jpg

Arghh...Done...
12_opening_done.jpg

Now getting out this blue stuff (2 hours).
13_getting_out_the_stuff.jpg
14_done.jpg

Now the thing with fibreglass is: if you don't bake it it will melt at a temperature point of about 60 to 70 °Celsius. While I wanted to place the battery inside the case and also wanted to ride my bike in summer I had to build an oven to bake the case for a minimum of 10 hours at the wanted resistance temperature minus 30°Celsius. Means: If I bake it 10 hours at 100° Celsius it will be stable up to about 130 °Celsius and so on.
I found an old metal corpus on the attic I transformed into an oven. The rest of the styrofoam for insulating, three 100W bulbs for heating. And a joint thermometer for measuring.
15_oven_for_baking.jpg
16_oven_for_baking_closed.jpg

My temperature curve. By the way: you should not rise the temperature to fast (10°Celsius per hour). I got up to about 80°. Enough for my needs I hope. Means stable till about 110°.
17_temperature_curve.jpg
 
After baking I had to do a lot of grinding, drilling, preparing the electronic parts by soldering water proof connections and so on. And of course the finish of the case. I will not go in detail by now. Look at the images.
18_electronics1.jpg

The big connector you see here is for the 3 motor phase leads. It's water prove just in case. When I have to dismount my rear wheel for repairing I just disconnect this one and bring it out of the case through that big hole you see in the picture above.
19_electronics2.jpg

20_electronics3.jpg

With the lock I can start the system. And also close of course.
21_electronics4.jpg

In here will sit the battery:
22_accu_holding.jpg

I made some mods on the battery itself for better handling.
23_accu_mod.jpg

Mounting the battery:
View attachment 3
There is some space left for carrying something (like the charger unit).
25_fastening_accu.jpg
26_connecting_power.jpg

Closing the case:
 
Thanks for your welcoming..
No. The epoxy is also part of the fibreglas (its the so called matrix). Its just the separating agent (something like wax) which would destroy the styrofoam. And you need some separating agent because it makes it much easier to get the laminated thing off the form...
 
There are many products you can use.
I think you have to find a shop in your country which is specialized in composite technology.
I have all the epoxy stuff from a Swiss online shop:
http://www.suterkunststoffe.ch/pdf/produkteuebersicht.pdf
pages 132/133
I used "SCS-Wachs-Trennmittel" on page 132. Worked perfectly.
And the (German) forum I got my knowledge from: http://www.r-g.de/
 
way cool. how did you make the side panel?

this has gotta be the most top notch without going over the top.

very applicable to other bikes, was it too large to fit inside an electric oven? now i am gonna watch CL for super large electric ovens, big enuff for the molds to fit inside. let it live outside under the woodshed to make them.

if you did not need access later, you could put in a lot of mold release, then cut it right down the middle or maybe leave the foam in place and dig out a cavity to mount the cells or pack, then close it and attach the two sides around the perimeter with tape, attach straps or brackets with mounts to strong points molded into the case.

way cool, very inspiring.
 
thanks for all the nice reactions..
@dnmun:
yes, too large to fit in a standard electric oven : )

the side panel is completely flat so I decided to make it out of an acrylic glass plate (3mm).The advantage here was that I could hold it over the opening to precisely draw the shape on it because of its transparency. However I run in minor problems getting the finish on the surface (there was some chemical reaction I did not understand...).
The closures on both sides - the case and the side panel - were formed out of an PVC profile, which I could heat deform to get the curvatures:
View attachment 3
Front part just filled with glue (a bit primitive, but worked). You see the tiny cracks in acrylic glass? They happened when I was cleaning the acrylic glass with aceton before applying the primer. Strange. And I don't care.
side_panel.jpg

By the way: The only glue I used was a two-part adhesive. This one is the flagship of this huge glue company UHU. Take a look at the specs. I always raised the temperature with a tiny radiant heater up to 50° to 60° Celsius where I thought it was important...
View attachment 1
sorry bad picture...
uhu_endfest_specs.jpg
 
Looks like quite a bit of work and it came out very nice so was definitely worth it. Appreciate the DIY it will be helpful to some I am sure. Thanks for the post.
 
Awesome job. Very nice indeed. I was toying with the idea of a sheet metal enclosure, but now that I have seen this I might have changed my mind.

How is the side panel held in place?
 
You really did a very nice job! makes me glad to know that people (you) can research topics and learn from each other. you started w/ little or no composite experience, and self taught off of things on the internet. you even built your own oven!! then the impressive ramp-up and cure of your cook along with a plot is really very cool! again very nice work. you should be proud of your self. i hope you get alot of enjoyment from your bike for many many years.

p.s. i used to be an aircraft mechanic for over 10 years and specialized in advanced aerospace composites (carbon fiber/fiberglass/metal bonding)for most of my career.
 
@ adrian_sm
It's just the triangle geometry: when closed the lock cylinder fits exactly in the hole and blocks any movement in ride direction and the profiles on the two longer sides of the triangle are then interlocked so the only method to open the case then would be brute force... :evil:
side_panel_construction.jpg
The wet weather concept is that the water flows inside the profile on the case itself, which goes completely all around the opening. In case water gets in the case it will hopefully flow down to the very lowest point where I provided a hole. There are a couple of other holes on the downside and the rear side of the case to assure some airflow to cool the battery and mainly the motor controller...
 
Good stuff. Looks real pro when finished. I did fibre glassing some time ago, I hated it.

Seeing this thread i will probably use it to house some lithiums myself. Very versitile and very informative thread, thank you for sharing.
 
e-cannon said:
@ adrian_sm
It's just the triangle geometry: when closed the lock cylinder fits exactly in the hole and blocks any movement in ride direction and the profiles on the two longer sides of the triangle are then interlocked so the only method to open the case then would be brute force... :evil:
Cool.
So the lock barrel somehow gets out of the way when you remove the side panel? Does it come out into you hand, or retract back into the enclosure?

e-cannon said:
The wet weather concept is that the water flows inside the profile on the case itself, which goes completely all around the opening. In case water gets in the case it will hopefully flow down to the very lowest point where I provided a hole. There are a couple of other holes on the downside and the rear side of the case to assure some airflow to cool the battery and mainly the motor controller...

Ahhh. That makes more sense now. Should work nicely.

Any issues with heat buildup? I was playing with ideas of allowing airflow through my battery box, while avoid water ingress, but was not sure if a really need it. I have never had my batteries or controller feel hot. With my super accurate "calibrated" hand, it is hard to tell if they are more than a few degrees above ambient.
 
BEAUTYFULL WORK, you are to be admired for such thoughtful work. I have seen a lot of things fabricated in my 65 years and this rates in the top tier. always keep this in your mind. DO the best job possible at anything you set your mind to build. :D :D :D :D :mrgreen:
 
@ BLUESTREAK:
Thanks! :D

@ adrian_sm
the lock barrel retracts. its a furniture lock that could be locked in both positions.
lock_drawing.jpg
using these components:
lock.jpgswitch1.jpg
 
adrian_sm said:
Any issues with heat buildup? I was playing with ideas of allowing airflow through my battery box, while avoid water ingress, but was not sure if a really need it. I have never had my batteries or controller feel hot. With my super accurate "calibrated" hand, it is hard to tell if they are more than a few degrees above ambient.

I read in the manual that comes with the ezee kit:

"If you plan to ride in hot weather, without pedaling up
steep hills, etc., mount your controller outside of the
battery bag to prevent thermal shutdown."

My controller is mounted with some spacing around it so its maybe not comparable with bag surrounding it but I just decided to drill the holes. They are placed in the middle axis of the case and the bicycle frame so I don't think there will be a direct water ingress. The most critical point is maybe the short end of the triangle where the side panel just overlaps the profile but an eventual water ingress there won't hurt anything...
 
e-cannon said:
@ adrian_sm
the lock barrel retracts. its a furniture lock that could be locked in both positions.
file.php

Very neat. I like how you have integrated the enclosure lock with the main power switch. Makes for a very clean look.
Does that mean when it is powered on the side panel might be able to slide off while you are riding.

Sorry for all the questions. But I have been inspired, and am now thinking of tackling something similar myself.
 
adrian_sm said:
Does that mean when it is powered on the side panel might be able to slide off while you are riding.
no. while riding the lock is always in "pos. closed". it's a push-button switch (push once - ON, push again - OFF). So starting the bike goes like: put in key, rotate, push down, pull back (you do not actually have to pull 'cause there is a spring in the lock), rotate back, pull out key.
if you rotate it back after "push down" you can pull out the key in the "pos. open" , the barrel will remain there and you can then open the case (with sometimes ON, sometimes OFF system, then I just turn off the battery on its own switch).
 
adrian_sm said:
Sorry for all the questions. But I have been inspired, and am now thinking of tackling something similar myself.
no prob. I would like to expect something like that: :D
T173_1_052i.jpg
 
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