Newb questions

GoreWound

GoreWound

New Member
I have a pedal bike that needs too much pedaling, but I'm cheap.
how is the following plan?
1) Purchase used 18v electric drill to gut for it's motor and speed controller
2) Replace the front cassette with a freewheel one.
3) Chain/ziptie/bolt everything to the bike
4) Emergency lantern batteries on a tail rack.
5) Enjoy seven speed electric moped

I've done a gas bike before, but never really messed with electronics other than really basic stuff like a trailer light kit.
Thanks for the help guys.
 
I have seen a friction drive e-bike driven by a pair of 18v drills. I have not seen a mid-drive based on drills. Sounds like a fun project.
 
well I tuned the derailleur and oiled the chain tonight, going to buy the drill tomorrow.

if two of these motors can do a friction drive, I would hope one with some reduction and seven speeds has a chance at least.
 
How much is all that going to cost? I could be wrong but that might be a lot to ask from a drill. But good luck I hope you pull it off!
 
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I got the drill today, and took it apart. my plan it to put three six volt lantern batteries together, and re-use the controller.

the motor is encased in metal (some drills i've seen on youtube let the plastic body double as the motor case) and the gearbox came off fairly easily.

looking at the motor itself it has a heat fit gear on it, I may have to use that gear. other than that the shaft is much smaller then I would like, but it should do. I was thinking of maybe using the gearbox built into the drill, but most of the case is plastic.

more take-downs and maybe batteries tomorrow.
 
woah, neat.

probably not gonna buy that though, cool as it is, this is practice for buying a bigger e-bike kit later on.
not to mention a sort of "can I build something like this out of garbage?" kind of thing.

I was playing with the gearbox parts, and I think I might try and use it. the shaft coming out of the motor is way to small to use without some kind of custom gearbox work, so I might as well see if the gearbox I have is of any use first.

also I noticed that the head sink on the controller/trigger is remoted with about three inches of wire, this means I can upgrade the heat sink fairly easily.
 
I can see the virtue in using a power tool in cost, availability etc. The motors are usually small brushed units in the 400/600 size. For the cost of a decent drill, this type motor could be used. I am assuming a sensorless controller would work with this. This is a fairly powerful motor and could be used as an FD/shaft drive. The shaft is 5mm and hardened. The motor case turns and with some "grippy" surface would make an FD on lower voltages. It also could be used as a driving surface for a flat belt.
The voltage is inline with the drill battery. The lantern batteries wont last long and cant be recharged, standard ones any way. This is just food for thought, not trying to "upset" your drill build. http://hobbyking.com/hobbyking/store/__18233__Turnigy_D3548_4_1100KV_Brushless_Outrunner_Motor.html
 
that's a nice motor, I might look into something better if the one I have craps out on me. but for now I want to see about strapping it on and seeing what happens.
About the batteries: I am already looking away from those lantern batteries, and have been thinking about something like this http://www.batteryspecialist.ca/6-v...nd-es8-2-6s/?gclid=CO_O34eVssgCFY6EaQodCNUCtw
three of those should have me up and running.

I know lead-acid are not the best, but I fully expect to break something during this "test run" project, so anything I have to buy I want to buy the least expensive kind I can. I also happen to already own a battery tender that can charge this type of battery.

right now the goal is less about building a really good e-bike, and more about seeing what sort of e-bike I can cobble together for under a hundred bucks.
 
I like the under a hundred bucks concept. Maybe there should be a build off to try different ideas.

The SLA battery isn't too bad in that size, three are only going to weigh 7.5lbs. 7ah is a good bit for a small wattage build. I'm getting pretty good distance/duration from 5ah with a DD hub motor. I ride in flat land so that influences it a lot, but I like the idea of a minimum system. Will be following to see what you come up with.

Isnt your drill 18v though?
 
it will probably end up more more in the vicinity of two hundred once I buy a freewheeling crankset, but hey whatever.
hopefully the short battery-lifespan will be mitigated by short trips, and mostly being off unless I'm trying to climb a hill. by my seriously under-par attempts at math I am relatively certain I am going to be getting about half an hour to forty five minutes of charge time. this is an estimate because I can only guess at the wattage of the motor.

my plan is to wire the three 6v batteries in series to get 18v hopefully I will be able to charge them while wired this way (supposedly something my battery tender can do, but only science can prove it)

as far as costs, I'm keeping those way low thanks to the motor being from a craigslist drill (only twenty bucks) I'd have saved more if the batteries worked, but for twenty bucks I doubt I could buy a comparable motor new.

the biggest hurdle right now is building some kind of transfer case, I was hoping to reuse the drills gearbox but it's way too long. so I will need to put a freewheel sprocket, and a gear that meshes to the motor on it or something.
 
Duh--I didnt catch the batteries were 6v. Makes sense now. You could mount the drill to the seat tube and make a side wall or rim drive FD just by chucking in a suitable FD roller.
 
my plan is to mount the motor to the underside of the bike right in front of the bottom bracket (there's a set of bosses there for a bottle holder) then run it with a chain to a set of freewheeling cranks.

I have no misconceptions about the power of this motor, so I want to hedge my bets by running it through the derailuer. a friction drive would be way easier (i probably wouldnt have even needed to take the drill apart) but I am considering this a practice run of the process to see if I have the confidence to try a mid-drive conversion kit.

not to mention that wrapping my mind around how middrive e-bikes are built has given me some really good ideas for my gas-bike (that project became stalled earlier this year, but some research into freewheeling cranksets has stirred the creative fluids)

my biggest issue it one of driveshaft size, the shaft on the motor is tiny, and I need to build a transfer case just so I can step up the size of the saft to fit a sprocket. today I was gonna have another crack at gutting the transmission from the drill, I hope theres a good gear on the opposite side of the chuck shaft, if there is I just need a bit of plate to mount it to, if not I may have to get creative.

if nothing else works I was thinking it might be possible to use a belt drive from the motor to a shaft that can support a sprocket.
 
I admire your engineering tenacity. I would think if this is an exercise to make a drill powered bike then using the drill in its entirety would be the build mode. This would allow quick replacement when necessary.

I actually put hands on my drill to have a look. It appears to have a 600 size motor from what I can see. Whats neat is it has a two speed gear box and is reversible in case you need to back out of a parking space-hehe. The two speeds would really be useful. There would be a good bit of torque available at the drills chuck. Which would make ratio changes pretty quick if one had premade sprockets/drivers.

Heck using the drill as is one could rig some sort of linkage to even use the existing trigger remotely as the throttle. Mine has a fairly linear throttle curve, more so than my Ebikes throttle. A simple lever mounted to the drill to press on the trigger and linked to a throttle control would work fine. This is a 600 can motor.
http://www.electrifly.com/motors/speed600.html

Hmmm. !
 
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thanks.
You are speaking the truth, having disassembled the drill I have learned that I shouldn't have. But none-the-less I am going to push forward, at this point using the motor for a mid drive is unfortunately just not compatible with using the transmission components from the drill. I am looking around for solutions to the 5 millimeter output shaft size (it seems that the chances of finding a gear that meshed with the one on the shaft are zero)
basically the goal it to have this be the output.
Motor->Scene Missing-> Bicycle Chain

if I owned a lathe I would have made a collar already, but I don't. also if I use a pulley to go from the small output shaft of the motor to a larger shaft with this freewheel I can easily build in a large step of reduction there.
I have saws, and a drill press. A bench vise too. So I should be good for making a transfer case out of a bit of thick plate. At this point any critique on that plan would be very much appreciated. I am having trouble finding solutions with Google-Fu, I did find a Japanese sprocket manufacturing firm that has a plant nearby, but custom is a bit out of my price range.
sickbikeparts seems to have almost everything else I need, that freewheel, and the crankset I would need too. I think they sell bare keyed shaft, not sure abut bearings though (I would need bearings that have a bolt on flange around them) Also this thing I build it going to be a bit of a mess of washers, I'm sure.

If I was starting again I would have bought an angle grinder instead.
I would have been able to build a mount for the assembled tool, then attached a sprocket to it instead of a cutting disk.
the most complicated part would have been figuring out of to remote the trigger. meh, whatever. My drill basically got me a $40 electric motor for $20 and it came with a controller.
 
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