Bedini-Cole 1971 to 1984 built from lab notes WINDOW MOTOR

[brodonh]

Hi Mr Bedini and All,

I'm in the process of taking a shot at duplicating this thread title Window Motor.

http://www.youtube.com/watch?v=F3QHsoyGH5I

I have a suitable rotor size piece of AL on my lathe at present and will be drilling the shaft hole when the extended drill comes.

I chose AL for cost and ease of machining.

My only question to Mr Bedini at present is:

Are the ceramic mags sized 1" x 2" x 6".

I want to wind and trigger for torque so if you can give basic info I'll follow your advice.

I'm guessing that your rotor was turned to about 6.9"D before milling.

Any help is appreciated but I know that you are very busy.



bro d

[brodonh]

Hi All,
Well into machining the rotor.
One non fatal flaw so far.
The flats are done and almost half the mag slots.
Will continue.
bro d

[brodonh]

Hi All,
Got the rotor roughed out with the milling operation.
Now need to fit the mags and leave a little room for adhesive.
Looks OK.
Will be using plates to hold the mags while running.
Needs some advice on bearings for this 30lb rotor.
Have plenty of pics to share soon.
Would love to hear from Tom C about windings for 1x2x6 ceramic mags and 7"D rotor.
Looking for torque.
bro d

[Tom C]

Don,

after you get the mags on the rotor, take a screwdriver and "feel" for the edge of the magnetic field coming off the center of the magnet face. that "edge" is where you want the back edge of the winding to sit. start with 300 turns of 20 and go from there. you can always add or remove turns. it will depend upon the number of mjl's you have paralelled on the B.C. switch. if you need 21193's let us know. we may have some already matched. you need the 21194 and the 21193 to be beta matched for its set and beta matched with each other. match the base resistors also and the drop on the diodes.

Tom C

[brodonh]

Thanks Tom,
Just what I needed to know.
Any advice on bearings etc.
Rotor is ready for mags.
Need to install a longer shaft.
Hope the pic gets through.
bro d

[Tom C]

Fafnir bearings, stay away from peer...

Tom C

[brodonh]

Rebored for .75" shaft - was a little too much over on the 5/8".
"Get the shaft bore right before milling."
Waiting for mag keeper stock.
bro d

[brodonh]

Hi All,
Rotor is done, check pics.
Looks OK.
26lbs
Gonna mount it for one coil to check balance and response to power.
thanks
bro d

[guyzzemf]

Very nice work:d

[Tom C]

Don,

I found a dynamic balancer at a place that winds electric motors. they can probably do it for you. love the mag holders

Tom C

[brodonh]

Hi All,
Starts shaking a little a 900rpm.

Best RPM requires about 25deg timing advance with hall triggering. Advanced from mag flat perp to coil.
I wound 300T with 3/#22.
I tried it first with trigger strands. At 30v it would take .3A and do 650rpm. The power winding: 15.2ohm.
With the hall triggering using the 3 strands in parallel it would only do about 1000rpm/ advanced timing.
3/4"D steel shaft. grease in bearings.
I'm concerned about the effect of the AL mag keepers. Would these be a hindrance eddy currentwise?
How 'bout the AL rotor.
I was expecting more torque and higher rpm than what I've seen so far with the one coil. 3 strands in parallel:5.2ohm.
I'll get it balanced and build a quality frame.
Tom, what would be a good starting turn#, winding 3 coils?
Thanks,
bro d

[Tom C]

Don,

I have not made a multi coil machine, add or remove turns to get what you want.

Tom C

[urcoffeetastestoasty]

The window motor can preform better if you use the coil trick.

greets,
JP

[brodonh]

Hi JP,
Interesting direction.
I'm focusing on this thread title WM.
Your discussed motor is not a window motor.
In a window motor the rotor is always surrounded by the coil(s).
Hence "Window" motor.
Be encouraged. We all have to investigate.
Thanks,
bro d

[brodonh]

Hi All,
Got the rotor balance and it's good for 10,000rpm.
Auto machine shop did it.
I'm in the middle of building a small cnc desktop Mill/router so the WM may be delayed for a bit.
Hoping to mill my own cct boards etc....plus get quainted with the tech and sofware with and eye for moving into a "big boy" cnc mill.
bro d