[BobDiode]

NEW 8 hp Brushless motor that weighs 10 pounds and costs under $300.

[nozza36]

BOBDIODE , you are a star ! i've been slowly planning a bldc
motor build but was worried about what to use as a main shaft for the rotor , you've just given me the perfect solution for a sturdy build ,
i'm off to the scrapyard to pick up a lorry alternator !
MANY THANKS !

[BobDiode]

Originally Posted by nozza36

BOBDIODE , you are a star ! i've been slowly planning a bldc
motor build but was worried about what to use as a main shaft for the rotor , you've just given me the perfect solution for a sturdy build ,
i'm off to the scrapyard to pick up a lorry alternator !
MANY THANKS !

With a little machine work on the shaft two of the shorter housing halves can be used with a 17 x 40 mm bearing on each side. Good Luck!
http://www.hydrogenappliances.com/cores_and_coils.html

[gostadler]

BobDiode sure came up with a good idea.

Has anyone thought of using one of those old Chrysler Corp pancake alternators, some were like 100 amps, reason is, the rotors are very large in diameter and the same magnetic field / current might give you a very much higher torque because of the leverage advantage of the large diameter rotor.

gostadler@yahoo.com

[BobDiode]

You need a PM rotor to make it worthwhile.
You can buy a brand new PM alternator with the strongest magnets available on E bay for under $200. 1/10 of it's power will flip over a bicycle.

[Rollie]

Does this controller pictured need position sensors or is it sensorless? If it needs position sensors would it work to take an inexpensive rc motor and marry it to the back of the alternator for a simple position sensor?

[BobDiode]

Originally Posted by Rollie

Does this controller pictured need position sensors or is it sensorless? If it needs position sensors would it work to take an inexpensive rc motor and marry it to the back of the alternator for a simple position sensor?

The Castle Creations HV 45 amp ESC is Seensorless and programable. A 3 wire hook up to the 3 phase wires.

[Fujiyama1]

HI guys , new to the scene, are you converting the lorry alternator into a 3 phase motor , do you need some feedback from the shaft
re
Barry

[Fujiyama1]

hi yes it does need feedback , is it easy to build
Barry

[BobDiode]

Originally Posted by Fujiyama1

hi yes it does need feedback , is it easy to build
Barry

A sensorless controller is all you need. If you make a magnetic PM rotor or buy a Delco PM alternator the PM rotor is already installed and there is no need to waste power energizing the field coil.
If you do want a sensored controller to commutate the rotor you must make a hall sensor board using three $1. hall sensors that can be epoxied to a fiberglass board and mounted in the right place for 60* timming.
This is a small 5 lb Ford PM Alternator / Motor with a hall sensor board and hall sensor controller used for a Electric bike that goes 45 MPH.
http://www.youtube.com/watch?v=El52vYPIEC0

The picture below is a Delco with and without a PM rotor. Notice that with the Claw Pole rotor without a PM rotor needs a pill magnet disk used to trip the hall sensors. A sensorless ESC is much eaiser and does not need hall sensors or a commutation disk.