KAZUALT said:
If you would do this setup and had around a little extra cash laying around what would your setup be. Please include battery specs and any links that you have. I am not a rich man so keep it affordable.
Well, mine would need some definite DIY, probably not what you really want. I dont' have links to anything, but there's recent threads on ES about everything except the first part.
There's probably an old thread somewhere about that, too, but I haven't found it yet.
If it had to be hub motors, I'd try building a couple of hub motors out of old cieling fans (find a couple identical ones with the right number of teeth on the stator, rewind them for 3-phase delta/wye for "two speed" operation). The catch is finding cheap magnets to replace the induction ring with; the only "easy" good source of them is other people's dead motors, in which case the fan motor cores are not needed, and just rewind the dead motors (if they need it). I always wanted to test out hub motors made this way.
There are some gotchas to this method, the first being that many cieling fan shafts are pretty crappy metal, and the second being that they are always *completely* hollow from end to end, making them probably much weaker for the single-ended mounting type of application. I have *one* of them that is from the 1980s with a good hard steel shaft, but so far haven't ever found another like that. So the shaft would probably have to be replaced. A flux ring to mount the magnets on would also probably have to be built, as the one that made it the ac-induction motor it started as isn't appropriately designed to just notch out for magnets to glue them in, as I understand it.
One thing that I would actually want to do, though, is to completely bore out the whole shaft area, replacing it with a core and bearing assembly with a strong solid axle that easily fits dropouts, and is not flatted and thus not weakened. Then the core outside that (threaded onto the shaft, or installed with a thermal difference between the two so it's press-fit is super-strong like the ring on a car clutch) would have threaded mounting holes to allow torque arm mounting to the core itself, with a much stronger resistance to twisting than a simple flatted shaft ever could. Then sealed bearings outside that core to ride the housing on. This method would prevent use of this as a *standard* rear hub, because there'd be no way to install anything that could attach like normal freewheel or cassette; you'd have to have a separate bolt-on single chainring to input to it. But it would work fine for front hub, especially a tadpole trike like this.
More realistically for you, I think I'd go with a pair of those new GM Magic Pies, because the concept is interesting and simplifies a few things on the installation; there's less wires to run to the motor (just power and throttle, maybe e-brake cutoff). I'd get whatever the highest power version is, if there is more than one, since I would want the trike able to climb hills easily without much input from my poor knees.
Single throttle, with the op-amp isolation/compensation circuit to send to both controllers, with the steering compensation offset circuit if needed. (I'd probably build that just to see how well it works.)
The throttle itself would be a pedal-tension-controlled throttle, with adjustable proportion control. That would mean that yes, I'd be pedalling all the time to run the motor, but I wouldn't have to have a separate throttle control to deal with--just pedal as hard/fast as I want the thing to go, shifting gears for pedalling as needed to keep it at the tension I prefer for the speed I'm at.
The adjustable proportion control would basically just scale the output of the pedal controlled throttle into the system so that the "hardness" of the pedalling would be adjustable; if you like to pedal a lot you just set it so that you have to push pretty hard to get motor output. Say, set it up equal motor output power to pedal input power. If like me you have bad knees, you set it so that you get about, oh, five times as much motor output power as pedal power.
Then it's not really pedalling, just using the pedals as an accelerator.
The control wouldn't be something you have a big control for, this is a screwdriver adjustment on the throttle-control-adapter box, so nothing you have to have on the bars; range of 1:1 to 10:1 should be more than adequate.
I'd build an A123 based pack using whole DeWalt packs, plus the adapters available elsewhere on this forum. Lots easier than yanking cells and building my own packs. I am not sure how many packs or exactly what series/parallel configuration, but something that gives me 48V, most likely. The actual Ah total would depend on the weight of the final vehicle, so I could figure out what kind of power levels I'd need to get the range I'd want.
Short of being able to afford DeWalt packs, I'd go for a Headway pack from EVComponents, probably, unless someone else reliable and "local" to the USA has them for significantly less. Same thing for V and Ah as above.
Can you use a disk brake on a e-hub?
Sure; you just have to make sure that it has rotor mounts on the hub, or a place for a standard adapter. And that you have clearance on the frame for the caliper mounts and such so they actually line up with the rotor.
