Amberwolf
09-11-07, 07:51 PM
(ok it's not really trademarked, but it's a funny name)
I've got a research blog (http://opporknockitytunes.blogspot.com/) going with more details, and questions or suggestions posted here may be reposted there by me, or you can post them as comments there yourself, if you like. Most questions I'll end up answering there in any detail, rather than here, where I will probably have a summary answer with a link to the blog post with the full detail (it saves space here and lots of typing or copy/paste).
Also, despite riding a bike for many years, I'm often not familiar with all the terms for parts, so if anyone is confused about what part I'm referring to, please ask, or suggest the right term--I'll correct myself to make it easier for everyone else to understand.
Don't expect calculations, efficiency measurements, etc, as while I would like to do them, I'm not sure at all how to go about them except roughly, and I'm more interested in simply achieving a working, relatively safe, design. If anyone wants to help me do those, or you can do them from data I can acquire at your direction, I'd be happy to post whatever is needed.
That said, the basics of it are:
1-- adding an electric-motor-assist to the bike,
2-- using recycled parts wherever possible
2a-- no kits, no hub motors, etc
2b-- the idea is to make a kind of "open source" project that anyone will be able to build from what can commonly be found as unused recycled parts, possibly even laying around their junkpiles or workshops. Thrift stores and such are a pretty good place for odd stuff, as are junkyards, but often I'm finding neighbors or friends are about to throw away (or have in a closet awaiting them getting around to throwing out) parts I need. So parts may not even cost anything at all, for many of them.
3-- the project isn't meant to power the bike on it's own--it's strictly an assist to the pedal power, and while I may end up with something powerful enough to move it all on it's own easily, it's going to have interlocks preventing it from being used without pedalling.
4-- I want to use the ability of the drivetrain of a bike to keep the motor as close to it's optimal speed for power usage as possible, meaning changing it's actual speed as little as possible.
More on interlocks (http://opporknockitytunes.blogspot.com/search/label/design%20goals) required, and other design goals (http://opporknockitytunes.blogspot.com/search/label/design%20goals) and features required (http://opporknockitytunes.blogspot.com/search/label/Desired%20Features) is on the blog (http://opporknockitytunes.blogspot.com/).
This is the bike I'm starting with:
http://farm2.static.flickr.com/1330/1362814921_ec5065b0b6_o.jpg
It's a 2005 Columbia 26" Comfort Bike, with an aluminum frame.
More info in this post on the blog. (http://opporknockitytunes.blogspot.com/2007/09/more-pictures-some-explanations.html)
I've already gotten a few ideas, some of which I discarded for safety reasons, which included the typical add-the-motor-to-the-pedal-gear or similar drivetrain inclusions. That one I discarded because there is the possibility of the motor kicking my feet off the pedals, or my feet slipping off of them, and me not being able to get them back on it time to balance myself correctly, and having an accident in traffic because of it. (I'm not a very athletic person, so even though I'm of average build and weight and such, I'm often quite discombobulated physically).
I discarded the idea of a friction-transfer directly from the motor shaft to the wheel, as it is not efficient, causes excess tire wear, and is likely to not work at all or very well when the wheel is wet.
So my current plan is to take the front wheel off, and mount essentially all of the rear triangle frame, wheel, chain, pedals, derailers, etc, from another bike to the front fork of the first bike. I do not want to destroy the original front fork, as there might be a reason or need to remove the modification and put the regular front wheel back on, in a hurry (I don't know what reason, but I want to plan for it. I love Ctrl-Z). It's a bit like what I later found Neodymics is trying to do, except that I don't want to put all the weight up in front like that--it affects steering too much, based on a mockup I tried with weights mounted to the fork that might approximate placement and mass of what I thought I would need at the time.
More info on the plan is at these posts on the blog. (http://opporknockitytunes.blogspot.com/search/label/drivetrain)
This is how Electricle™ Mk I, is envisioned at the moment:
http://farm2.static.flickr.com/1192/1362814927_4a679a13bb_m.jpg
A very basic 3D "sketch" of the design.
This is a temporary physical mockup of it, using the testbed bike I got from a friend, along with a part of the frame and drivetrain from an old rather-worse-for-wear Murray Biotech:
http://farm2.static.flickr.com/1428/1362814925_bc6b2507e7_m.jpg
More detail is here in the blog. (http://opporknockitytunes.blogspot.com/search/label/drivetrain)
Eventually, once I learn enough C to begin programming an AVR microcontroller (uC), I'd like to add electronic detection of when a gear change would be good to do, and signal the rider to what gear to change to. Later, when I know more of servo controls, I'd like to add control of the motor's derailers to shift gears for it automatically. (All pedal drivetrain controls remain completely manual, as none of that section is touched--thus no matter what I do wrong making the rest of this, or what fails, I could still get home entirely normally on pedal power, excepting a dramatic mechanical failure, possibly).
More detail is here in the blog. (http://opporknockitytunes.blogspot.com/search/label/Controller)
I've got a test motor from an old '85 Ford LTD's power window, which has not yet been tested in the drivetrain under load, only the basic fact of it's working to move the chain and wheel (haven't got the interconnect done yet, that should happen in the next week or so, depending on the friend with tools I need but don't have).
http://farm2.static.flickr.com/1230/1362814937_ec82e286f4_m.jpg
More detail here on the blog. (http://opporknockitytunes.blogspot.com/search/label/motor)
Batteries are going to be tougher. Those I will almost certainly end up buying new, probably the DeWalt 36V packs by A123, based on cost, energy density, and ease of getting identical replacement parts for the likely life of the bike, as well as the amount of info I've found about reverse-engineering them for other purposes.
More detail in these posts on the blog. (http://opporknockitytunes.blogspot.com/search/label/Batteries)
Please give me any feedback you have, whether critical or supportive, but in as much detail as you can of why and/or how you think it's good or bad, and in what areas. I only ask that you first read the entire existing blog and any comments there before posting, simply so that questions already answered, thoughts discussed, etc, are taken into account.
I have reasons for not using kit parts or hub motors, etc, partly to do with cost, partly with theft issues, partly with environmental friendliness (in that part of the purpose of this project and others is to re-use things otherwise going to the dump). If you don't see an explanation of why I am doing or not doing something, and you just don't see the logic, please ask! Maybe I didn't think of it!
I've got a research blog (http://opporknockitytunes.blogspot.com/) going with more details, and questions or suggestions posted here may be reposted there by me, or you can post them as comments there yourself, if you like. Most questions I'll end up answering there in any detail, rather than here, where I will probably have a summary answer with a link to the blog post with the full detail (it saves space here and lots of typing or copy/paste).
Also, despite riding a bike for many years, I'm often not familiar with all the terms for parts, so if anyone is confused about what part I'm referring to, please ask, or suggest the right term--I'll correct myself to make it easier for everyone else to understand.
Don't expect calculations, efficiency measurements, etc, as while I would like to do them, I'm not sure at all how to go about them except roughly, and I'm more interested in simply achieving a working, relatively safe, design. If anyone wants to help me do those, or you can do them from data I can acquire at your direction, I'd be happy to post whatever is needed.
That said, the basics of it are:
1-- adding an electric-motor-assist to the bike,
2-- using recycled parts wherever possible
2a-- no kits, no hub motors, etc
2b-- the idea is to make a kind of "open source" project that anyone will be able to build from what can commonly be found as unused recycled parts, possibly even laying around their junkpiles or workshops. Thrift stores and such are a pretty good place for odd stuff, as are junkyards, but often I'm finding neighbors or friends are about to throw away (or have in a closet awaiting them getting around to throwing out) parts I need. So parts may not even cost anything at all, for many of them.
3-- the project isn't meant to power the bike on it's own--it's strictly an assist to the pedal power, and while I may end up with something powerful enough to move it all on it's own easily, it's going to have interlocks preventing it from being used without pedalling.
4-- I want to use the ability of the drivetrain of a bike to keep the motor as close to it's optimal speed for power usage as possible, meaning changing it's actual speed as little as possible.
More on interlocks (http://opporknockitytunes.blogspot.com/search/label/design%20goals) required, and other design goals (http://opporknockitytunes.blogspot.com/search/label/design%20goals) and features required (http://opporknockitytunes.blogspot.com/search/label/Desired%20Features) is on the blog (http://opporknockitytunes.blogspot.com/).
This is the bike I'm starting with:
http://farm2.static.flickr.com/1330/1362814921_ec5065b0b6_o.jpg
It's a 2005 Columbia 26" Comfort Bike, with an aluminum frame.
More info in this post on the blog. (http://opporknockitytunes.blogspot.com/2007/09/more-pictures-some-explanations.html)
I've already gotten a few ideas, some of which I discarded for safety reasons, which included the typical add-the-motor-to-the-pedal-gear or similar drivetrain inclusions. That one I discarded because there is the possibility of the motor kicking my feet off the pedals, or my feet slipping off of them, and me not being able to get them back on it time to balance myself correctly, and having an accident in traffic because of it. (I'm not a very athletic person, so even though I'm of average build and weight and such, I'm often quite discombobulated physically).
I discarded the idea of a friction-transfer directly from the motor shaft to the wheel, as it is not efficient, causes excess tire wear, and is likely to not work at all or very well when the wheel is wet.
So my current plan is to take the front wheel off, and mount essentially all of the rear triangle frame, wheel, chain, pedals, derailers, etc, from another bike to the front fork of the first bike. I do not want to destroy the original front fork, as there might be a reason or need to remove the modification and put the regular front wheel back on, in a hurry (I don't know what reason, but I want to plan for it. I love Ctrl-Z). It's a bit like what I later found Neodymics is trying to do, except that I don't want to put all the weight up in front like that--it affects steering too much, based on a mockup I tried with weights mounted to the fork that might approximate placement and mass of what I thought I would need at the time.
More info on the plan is at these posts on the blog. (http://opporknockitytunes.blogspot.com/search/label/drivetrain)
This is how Electricle™ Mk I, is envisioned at the moment:
http://farm2.static.flickr.com/1192/1362814927_4a679a13bb_m.jpg
A very basic 3D "sketch" of the design.
This is a temporary physical mockup of it, using the testbed bike I got from a friend, along with a part of the frame and drivetrain from an old rather-worse-for-wear Murray Biotech:
http://farm2.static.flickr.com/1428/1362814925_bc6b2507e7_m.jpg
More detail is here in the blog. (http://opporknockitytunes.blogspot.com/search/label/drivetrain)
Eventually, once I learn enough C to begin programming an AVR microcontroller (uC), I'd like to add electronic detection of when a gear change would be good to do, and signal the rider to what gear to change to. Later, when I know more of servo controls, I'd like to add control of the motor's derailers to shift gears for it automatically. (All pedal drivetrain controls remain completely manual, as none of that section is touched--thus no matter what I do wrong making the rest of this, or what fails, I could still get home entirely normally on pedal power, excepting a dramatic mechanical failure, possibly).
More detail is here in the blog. (http://opporknockitytunes.blogspot.com/search/label/Controller)
I've got a test motor from an old '85 Ford LTD's power window, which has not yet been tested in the drivetrain under load, only the basic fact of it's working to move the chain and wheel (haven't got the interconnect done yet, that should happen in the next week or so, depending on the friend with tools I need but don't have).
http://farm2.static.flickr.com/1230/1362814937_ec82e286f4_m.jpg
More detail here on the blog. (http://opporknockitytunes.blogspot.com/search/label/motor)
Batteries are going to be tougher. Those I will almost certainly end up buying new, probably the DeWalt 36V packs by A123, based on cost, energy density, and ease of getting identical replacement parts for the likely life of the bike, as well as the amount of info I've found about reverse-engineering them for other purposes.
More detail in these posts on the blog. (http://opporknockitytunes.blogspot.com/search/label/Batteries)
Please give me any feedback you have, whether critical or supportive, but in as much detail as you can of why and/or how you think it's good or bad, and in what areas. I only ask that you first read the entire existing blog and any comments there before posting, simply so that questions already answered, thoughts discussed, etc, are taken into account.
I have reasons for not using kit parts or hub motors, etc, partly to do with cost, partly with theft issues, partly with environmental friendliness (in that part of the purpose of this project and others is to re-use things otherwise going to the dump). If you don't see an explanation of why I am doing or not doing something, and you just don't see the logic, please ask! Maybe I didn't think of it!