To improve the weight distribution of my current ebike I'm going to build a custom battery case that fits in the triangle of the bike. So the weight moves from the high back of the bike to the low middle.
I've got my inspiration from these threads:
http://endless-sphere.com/forums/viewtopic.php?f=6&t=13411
http://endless-sphere.com/forums/viewtopic.php?f=2&t=22771&hilit=custom+battery+case
Bill of material:
- styrofoam to make a mold
- Polyester resin -> 17/01/2011 -> Decided to go for Epoxy resin because polyester resin will react with the styrofoam
- hardener
- fiberglas cloth (5M2 should be plenty)
- latex gloves, respiratory protection mask and eye protection for safety
- filler to create a smooth surface (if necessary)
- Primer to create a paintable surface
- Epoxy based paint (black)
- Acryllic glass to make a door
- piano hinge for the door
- lock for door
- 2nd lock to switch my system on/off
-> 17/01/2011 -> I had some trouble finding a supplier in Belgium for my fiberglass materials so I looked online and found: http://www.polyestershoppen.nl, I can highly recommend this supplier he was interested in my project, keen on helping me and answered quickly on emails I send.
Questions on my mind:
- I know my polyester resin is going to eat away on the styrofoam, does a coat exist to protect the stryrofoam?, any other ideas to solve this problem?-> 17/01/2011 -> Opted for epoxy resin, problem solved
- What's a good way to attach the fiberglass case to my bike frame? -> 17/01/2011 -> Will use threaded rivets and threaded bolts
- It would be cool If I needed only one lock that could both open/close the door and switch the system on/off, any ideas? -> 6/03/2011 ->I've opted for a kill-switch, will need a second lock for the door. Cheap and effective.
- I'm thinking of using 1 layer of fiberglass on the sides and 3 layer in the corners, is it enough? -> 6/03/2011 ->I did 2 layers, 1 layer of fiberglass and one of carbon/kevlar
I'm still in the designing fase as soon as I start I'll make some pictures of the progress.
Any info/ideas are welcome
Progress pics:
17/01/2011:
Today I made a cardboard mock up:
19/01/2011:
I bought BASF Styropor insulation foam, only 4 cm thick insulation was available so I needed to glue them together.
After some sanding my foam mold is finished, I adapted the design a little bit to make some room for a larger chainring:
21/01/2011:
Because the controller needs airflow I decided to make a separate incasing for the controller this will allow me to make a hole in my case without compromising the waterproof concept, I made a quick sketch with sketch up. First I'm going to finish the main battery case, then I'm going to make the incasing out of cardboard so I can fiberglass it:
22/01/2011:
Construction can begin because today I finished my design and found a place for:
- on/off switch (battery kill switch)
- watt meter
- battery
- controller
06/03/2011:
OK guys so its bin a while, I had some busy weekends and I ordered some stuff online and it took a while to be delivered.
Today I've fiberglassed my mold. Don't mind the ski goggles, the fiberglass usersguide mentioned spray water proof safety glasses ... You will also notice the tight Tyvek suite, I borrowed it from my dad and he isn't as big as me.
It was my first time fiberglassing, I did one layer of fiberglass and one of kevlar/carbon. I used epoxy resin. I hope it will turn out ok, I'm pretty satisfied with how it looks but I'll wait with getting excited till its cured.
13/03/2011:
OK guys, another weekend, another job completed, it may not look like much happened but images can decieve...
During the week I decided to put another coat of resin on the box because I wasn't completely satisfied with the coverage (in some places I could feel the roughness of the cloth). So I did on Saturday.
Today (Sunday) I planned to sand it completely to make the surface nice and smooth. First I tried to fit my box in my bike but to my surprice it didn't fit anymore . I kinda saw this one coming because I knew I did (to) much layers in the corners to make it extra strong. This is typically me, when I saw I had some spare cloth and resin I thought what the heck, let's put on an extra coath for added strength .
So I've spend much of the afternoon sanding the one corner that didn't fit anymore. Offcourse I needed to sand that much that I had to sand into the cloth ... not very happy with that. It fit's now and I put a little resin on the places where I sanded into the cloth.
Next week I will sand the box as smooth as i can without sanding into the cloth and I will take the foam out (really curious if my release agent wil work ). Weekend after that I plan to make it completely smooth with some filler and put in my electrical stuff, final step will be painting and mounting it on the bike frame.
1/05/2011:
It's been a while but this weekend I finally found time to work on my box again. I finished taking the foam out. Special thanks to my neighbour, he helped and if it wasn't for him I would have quit and start again another time , my release agent worked but the space to work in was so small I went crazy at times.
When I found my sanity again, I started with the filler to make a smooth surface. The surface needed a lot of filler to make it straight but now it feels and looks pretty good. I need to do some finishing touches but I ran out of filler. Will do the last details another time, I also need to find a solution for the places where I sanded into the cloth, maybe I'll do some filler on it but then my box will not be straight anymore.
Next weekend will be electronics weekend I'm going to lay out the complete circuit and find places for everything in my box, I will mark these places and cut holes where needed.
I've got my inspiration from these threads:
http://endless-sphere.com/forums/viewtopic.php?f=6&t=13411
http://endless-sphere.com/forums/viewtopic.php?f=2&t=22771&hilit=custom+battery+case
Bill of material:
- styrofoam to make a mold
- Polyester resin -> 17/01/2011 -> Decided to go for Epoxy resin because polyester resin will react with the styrofoam
- hardener
- fiberglas cloth (5M2 should be plenty)
- latex gloves, respiratory protection mask and eye protection for safety
- filler to create a smooth surface (if necessary)
- Primer to create a paintable surface
- Epoxy based paint (black)
- Acryllic glass to make a door
- piano hinge for the door
- lock for door
- 2nd lock to switch my system on/off
-> 17/01/2011 -> I had some trouble finding a supplier in Belgium for my fiberglass materials so I looked online and found: http://www.polyestershoppen.nl, I can highly recommend this supplier he was interested in my project, keen on helping me and answered quickly on emails I send.
Questions on my mind:
- I know my polyester resin is going to eat away on the styrofoam, does a coat exist to protect the stryrofoam?, any other ideas to solve this problem?-> 17/01/2011 -> Opted for epoxy resin, problem solved
- What's a good way to attach the fiberglass case to my bike frame? -> 17/01/2011 -> Will use threaded rivets and threaded bolts
- It would be cool If I needed only one lock that could both open/close the door and switch the system on/off, any ideas? -> 6/03/2011 ->I've opted for a kill-switch, will need a second lock for the door. Cheap and effective.
- I'm thinking of using 1 layer of fiberglass on the sides and 3 layer in the corners, is it enough? -> 6/03/2011 ->I did 2 layers, 1 layer of fiberglass and one of carbon/kevlar
I'm still in the designing fase as soon as I start I'll make some pictures of the progress.
Any info/ideas are welcome
Progress pics:
17/01/2011:
Today I made a cardboard mock up:
19/01/2011:
I bought BASF Styropor insulation foam, only 4 cm thick insulation was available so I needed to glue them together.
After some sanding my foam mold is finished, I adapted the design a little bit to make some room for a larger chainring:
21/01/2011:
Because the controller needs airflow I decided to make a separate incasing for the controller this will allow me to make a hole in my case without compromising the waterproof concept, I made a quick sketch with sketch up. First I'm going to finish the main battery case, then I'm going to make the incasing out of cardboard so I can fiberglass it:
22/01/2011:
Construction can begin because today I finished my design and found a place for:
- on/off switch (battery kill switch)
- watt meter
- battery
- controller
06/03/2011:
OK guys so its bin a while, I had some busy weekends and I ordered some stuff online and it took a while to be delivered.
Today I've fiberglassed my mold. Don't mind the ski goggles, the fiberglass usersguide mentioned spray water proof safety glasses ... You will also notice the tight Tyvek suite, I borrowed it from my dad and he isn't as big as me.
It was my first time fiberglassing, I did one layer of fiberglass and one of kevlar/carbon. I used epoxy resin. I hope it will turn out ok, I'm pretty satisfied with how it looks but I'll wait with getting excited till its cured.
13/03/2011:
OK guys, another weekend, another job completed, it may not look like much happened but images can decieve...
During the week I decided to put another coat of resin on the box because I wasn't completely satisfied with the coverage (in some places I could feel the roughness of the cloth). So I did on Saturday.
Today (Sunday) I planned to sand it completely to make the surface nice and smooth. First I tried to fit my box in my bike but to my surprice it didn't fit anymore . I kinda saw this one coming because I knew I did (to) much layers in the corners to make it extra strong. This is typically me, when I saw I had some spare cloth and resin I thought what the heck, let's put on an extra coath for added strength .
So I've spend much of the afternoon sanding the one corner that didn't fit anymore. Offcourse I needed to sand that much that I had to sand into the cloth ... not very happy with that. It fit's now and I put a little resin on the places where I sanded into the cloth.
Next week I will sand the box as smooth as i can without sanding into the cloth and I will take the foam out (really curious if my release agent wil work ). Weekend after that I plan to make it completely smooth with some filler and put in my electrical stuff, final step will be painting and mounting it on the bike frame.
1/05/2011:
It's been a while but this weekend I finally found time to work on my box again. I finished taking the foam out. Special thanks to my neighbour, he helped and if it wasn't for him I would have quit and start again another time , my release agent worked but the space to work in was so small I went crazy at times.
When I found my sanity again, I started with the filler to make a smooth surface. The surface needed a lot of filler to make it straight but now it feels and looks pretty good. I need to do some finishing touches but I ran out of filler. Will do the last details another time, I also need to find a solution for the places where I sanded into the cloth, maybe I'll do some filler on it but then my box will not be straight anymore.
Next weekend will be electronics weekend I'm going to lay out the complete circuit and find places for everything in my box, I will mark these places and cut holes where needed.