Volter said:
The forkenswift story inspired me, if you have heard of that guy..
Yep, and there are other "forken" vehicles, too. Forkencycle, among other things. Take a gander thru http://evalbum.net there is some interesting stuff there.
I have the owners manuals for the GE EV-1 controller.. 36/48v I imagine the coil voltage is 12v..
Having the manuals will help, as it will tell you the pinout on the contactors, without experimentation.
I expect 12V coil most likely, but check the manual first.
Basically the kill switch itself will be just a switch that powers the coil on and off--your "ignition" switch. I recommend a keyed switch, simply for security. It needs to be somewhere you can reach it and turn it off VERY quickly while riding, in case of full-throttle-stuck-on failures.
I have my keyswitch in the steering tube on CrazyBike2, although because it's brushless it doesn't need a power-cut killswitch (they don't fail on the same way as brushed). I do still have a circuit breaker I can flip, right between my knees, whcih is what I used for killswitch when I had the brushed powerchair motor on there.
The contactor's power contacts will be wired in series with either negative or positive wires from battery to controller. Generally doens't matter which. If you were expecting problems and wanted double the safety, you could put a separate contactor on positive and negative, but it shouldnt' be needed.
If you don't have a 12V (or whatever coil voltage is) system on the bike already (for lights, horn, fans, whatever), separate from your traction pack, you can use either a DC-DC converter, a separate 12V battery, or just tap off the bottommost 12V battery in your traction pack. (I used to do the latter on CB2 when I had SLA on there, now it has a separate 12V pack. DayGlo Avenger has a DC-DC).
12V from there is then wired to one side of keyswitch, and other side is wired to coil positive. Coil negative goes to ground, as does negative of 12V system.
If I can get my trackball working again later tonight, I'll draw up a basic diagram, but the verbiage above covers it.
will the contator kill sw be necessary if I get a Kelley controller?
No killswitch is "necessary" with any controller, but I think that with any brushed system it's a *really* good idea.
In a car-sized EV, the brakes are probably good enough to stop the vehicle even if the motor is running full throttle/power, although this will blow the controller or motor if there's no fuse or breaker to stop the overcurrent. In a typical bicycle setup, they probably are not. Can be *made* to be, but I doubt yours is ATM; I know mine are not. Might be enough to pop the breaker if sustained long enough, but the controller or motor might be damaged before that, or you might hit something first.
Some really big EV controllers like Soliton1 have a contactor built in. The Zilla might, too. But they're way bigger than what you want.
I think they (kelley) have a contactor suggested when using that controller, can I improvise on that?
Theoretically you can use any contactor that's rated for the voltage and current you intend to run thru it. Might have to modify their wiring diagram depending on it's pinouts and such.
The bearing and sprocket place I go to is concerned about my using the 25 chain with this motor.
There's heavy-duty #25 chain made, though I don't know much about it. Most of what I have is stuff that came off exercycles, though I have a little I got from the used sale forum here on ES once.
I'm getting a larger sprocket for the driven, 125 tooth, and the Ohio motor is going to have a 16 tooth drive, since it is the smallest sprocket I can get with a 5/8" bore and 2 set screws.
That along with a lower rpm of 2250, hows that look? 24" wheels btw.
That depends...what RPM will your wheel be spinning at, at the typical cruising speed you want to be at?
How often will you be running below that speed but still at full throttle (like startups and hills)?
You want to determine wheel RPM first, then that tells you what ratio you need to convert the motor's expected operating RPM to the necessary wheel RPM. Then you can work out what actual sprocket sizes you need to achieve that.
With this setup I don't have room for different gears or changing gears, that's why I'm trying to get a better controller that is more programmable.
Ah, well, chainging gears is the efficient way to fix things.
Using current limiting in a controller will at least prevent damage to batteries/motor, when under conditions where shifting gears would normally be needed, but it will also limit your torque in those conditions, which will mean it takes longer to overcome them.
Now would it be possible for that motor to actually get 3500w? with the calculation of the 35a breaker putting it to 1680w.
Well, I had a 30A breaker, IIRC, on my CrazyBIke2 along with 36V of 17-20Ah SLA, and 2QD controller that theoretically should have limited current starting around 60-80A or so, maybe earlier (can't remember), but when I had a chain derail and start mangling sprockets/etc, pulling the rear wheel out of dropouts, bend rim, break spokes, destroy chain, all in like half a second, it was drawing well over 135A, well over 3500W, according to the watt meter. It happened very fast, so nothing had time to react, until the FETS blew.
I expect that for short periods, the motor was getting quite a bit more than what the breaker would pop at, because it can take 30 seconds or more for them to pop. Plus I've had many pushbutton breakers that didn't pop even at 25% over their ratings, in various devices. (and others that popped at less than half their ratings!). So I wouldn't trust a breaker to be a current limiter except in extreme cases.
It'll stop a continuous short from causing a fire, but that's about the only guarantee I might be willing to make of one. :lol:
Fuses can be a lot faster to react, but since you get current spikes at motor startup under load that are sometimes hundreds of amps, they're kinda useless cuz they'll pop all the time.
Electric scooter parts told me that motor was made to move around 250# at best. I'm not too much less than
that myself, yeah I could loose 20 lbs but that still puts me at a deuce hundo so... snap crackle bzzzt!
Yeah. Me an CB2 are 300lbs+, so.... it can take some big power to get us moving. Peaks on my 48V Vpower pack show as 60-62A very short term, and 30-40A for up to seconds at a time with a full-throttle startup from stop (whcih I try never to do).
I may move the batts to the lower shelf and put the motor up top.
That might help a lot with turns.
The lower you can put them the better off you are, so if you could put them *under* the rear platform, along the axle line, it'd be better.
I was actually wondering about lower rpm motors, like those used in wheelchairs..
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If you don't mind overvolting them to get higher speeds, they'll work, though they are not very high wattage individually (usually used in pairs). But remember that they are actually not all that low RPM in there--they use gearboxes to get that down quite a bit. IIRC the last one I used was about 1300-1500RPM at 24V, with the gearbox reducing that to about 100-120RPM at the wheel axle. Then I ran that at 36V, increasing all RPM proportionally, and put a sprocket on the output axle with chain to the bike's drivetrain input to make it about the same as human pedaling cadence of 80/100RPM typical/max. So it wasnt' all that fast, max about 21-23MPH I think, but had so much torque I could destroy the drivetrain with it (and did, multiple times).
Also, with those gearboxes on there, you won't be coasting, or just-pedalling, unless you put a freewheel on either the output shaft or the wheel-mounted sprocket.
http://4qdtec.com should have some good info on this.
we would do some damage on onna those beasts!
