Dual motor Schwinn Izip

[RebelPrinter]

Hi guys. I just lucked into a Izip (250w). What I would like to do is add a second identical motor run off the same controller and throttle for 500w total power to get going or uphill, but put in a cut-off switch for one of the motor to extend range at cruise It's mostly flat around here).

So the questions are, what size controller should I be looking for to run both motors, and can I set the scond one up on the rear wheel as well (split sprocket instalation on the right side) or should that go front drive ideally ? Or possible even get one of these brackets and run both motors on the same chain Amazon.ca

 

[Chalo]

Honestly, I think you'd be much better off spending your efforts on a bike that was made to actually work for more than just long enough to escape any warranty support. Those bikes were made in haste from compressed garbage, and their design intent was to fool people into buying them.

Hypothetically, a PWM DC speed controller like that can run more than one motor. But brushed motors are electrically very noisy, and having two on the same controller might cause voltage spikes that could glitch or damage the controller. If you want to keep it simple, though, you can try a controller that is rated for the sum of the motor current ratings or a little more. You would not be able to switch off one motor without the controller sending the extra juice to the motor that's still connected, so that part of your plan wouldn't be a good idea if you only use one controller.

It's kind of a tossup whether to connect two motors to the rear wheel, or one motor to each wheel. Either way, you'll have to do some parts fabrication that your bike will not pay back with reliable operation. If you have the amount of motivation and skill required to make it happen, you should apply them to a bike that might not be an immediate disappointment.

Another approach might be to find a more powerful motor that mounts the same way, and swap in that motor and a more powerful controller in place of what you have. That would be simpler, and easier to transfer to a different bike when you give up on this one.

 

[docw009]

More time and money than it's worth, unless you been collecting parts over the years. As Chalo said, it's a brushed motor which has two power wires to the motor. Speed depends on the average DC voltage level, Rather than change the DC voltage, the controller chops it up into pulses, with the higher pulse rate giving a higher voltage.

You can look for a higher current brushed motor controller, but you'll need a bigger battery for the higher current. I believe you could run two motors off the same controller, as long as it could supply enough current. Probably better to have a separate controller and battery,

It would also be better to find an old brushed motor for the front wheel, along with a suitable controller/battery, A separate motor with chain would be too wacky,

Even better to junk the IZip and put a stronger hubmotor in the rear,

 

[RebelPrinter]

Thanks guys. I do have just about everything on hand. Kind of a mish-mash of parts I have picked up as part of auction lots and held onto, and fabbing or 3d-d printing is no problem. The batteries are 33aH UB12330 mobility scooter batteries from my own scooter (I am diabled) that got replaced. I might need a new 20-buck controller and thats about it.

Now to hunt down the thread on 2 controllers on one throttle.

 

[amberwolf]

with the higher pulse rate*** giving a higher voltage.

***width. [/pedantic]

Now to hunt down the thread on 2 controllers on one throttle.

Just feed the throttle 5v from only one controller (whichever one is always powered on during system usage), so that you aren't potentially damaging one of the 5v sources by connecting them together.****

Throttle signal goes back out to both controllers.

If you are powering both controllers from the same battery, you can also just provide ground to the throttle from one controller to minimize ground loop issues.

**** (note that there are some brushed controllers that use only potentiometer type throttles that this doesn't work for, because they use the current thru the potentiometer's 5v-to-ground portion as a safety check to be sure the throttle is actually functioning at startup, and will disable the controller if it's not wired and working correctly. In these cases, you can't use a single normal throttle to run both, you'd have to use two that are mechanically linked, or replace the pot in a single throttle with a dual-potentiometer (like a stereo volume control does). If you replace the pot, be sure to use the same type; there are linear, logarithmic, and others, and the wrong kind will change the way the throttle mechanically creates the signal from your movement.