running a single phase motor of a bldc controller

[nathandance1996]

I was wondering if you could connect a single phase motor to the output of a bldc controller (3 phase), if you connected the motor to two of the three wires from the controller would the motor run? because that would make finding a motor for my bicycle a lot easier. I have also been experimenting with brushed motors, but haven't been succseful, would a bldc motor and controls be affordable? currently i have some engineering skills and have built a 2 stroke bicycle earlier this year.

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[amberwolf]

The controller probably wouldn't do anything because the hall sensor inputs aren't receiving commutation signals.

There are controller chips that can do both brushed and brushless, the MC3303x series, so in theory you could use Jeremy Harris' Simple BLDC Motor Controller (a search on ES will find the thread), modified for single-phase, to do this.

But it is probably a lot easier just to use a brushed motor controller intended for the purpose.

I also don't recommend using an induction motor for running your project, as they don't work they way I think you might be expecting them to. You'd need an inverter to create AC of the right frequency to drive it, and it only operates well at a particular RPM if at only one frequency. Gets more complex after that.

 

[liveforphysics]

Sadly, it absolutely will not work.

Avoid single phase AC motors like the plague. Huge big heavy motors that are extremely feeble and only made to operate well at a single RPM.

If you really must scavenge a motor out of scrap or something, a motor from a normal corded drill, a vacuum cleaner, a grinder, or any other household device that uses a universal motor will happily run straight off DC (even better than it did when plugged into the wall). You will need to have a ~110v battery to make it have useful power though, and a painfully complex and elaborate gearing reduction system.

I would really invest in a brushed or brushless ebike hub if possible. It's going to leave you so much happier in the long run.

 

[nathandance1996]

I will stick to brushed dc motors, any idea how to transfer mechanical power to the wheels? I'm trying to build a friction drive setup that will be easily disengage and easy to build, I do have access to a mig welder as well as my homemade carbon arc welder. I have two motors, one 24v 250w 2750rpm and the other is a geared 36v 500w 450rpm motor. i also have some wheelchair motors as well.

 

[amberwolf]

There are quite a few tried-and-tested ways in various build threads around here. If the regular forum search doesn't find them, try using the Google site-search feature.
http://www.endless-sphere.com/forums/viewtopic.php?f=13&t=32102

Personallly for as much power as things like wheelchair motors can deliver, I'd go for belt or chain drive (see CrazyBike2's various early drivetrains with them).

 

[liveforphysics]

as well as my homemade carbon arc welder.

I always enjoy seeing home-brew welders. I would love to see some pictures of your unique welder build if you don't mind.