Scott's efficient DC motor

[gmeast]

I would recommend this site over the others any day - the interface is straight forward, and the patents are available in PDF format already, no tiff plug-in required.

http://www.freepatentsonline.com/  account is free and I never hear from them.

@ jadaro2600 ,

The post is about the motor not the PDFs.  The Search features on the USPTO site is very more useful than the site you recommended.

[gmeast]

Hi Laurent,

Thanks for comment on water sparkplug.  Too bad the economy took me down. 

Are you going to use the motor in your ultralight?  That would be cool.  Wish batteries didn't weigh so much.  When Scott was using my shop for making his motor, we talked about how he would control it.  As I recall he wanted to run the motor in repulsion mode because he said that gave him better flexibility and options for recovering the BEMF and possibly running COP>1. 

His motor also used (uses) air-core coils so there is no hysteresis, lenz issues or eddy current losses (other than in the copper coils).

As far as I can tell, the patent covers what he did.  Don't know where he is or what he's doing now.

Greg

Hi Greg

i follow your work since a long time on an other Forum  and i am happy that you bring this motor idea here .

Perhaps you have seen the Ossie motor thread where i posted my contribution with a sandwitch rotor  very similar to the Scott' s one.

So far i remember you made really usefull work with your water fuel car as we name it here in europe " la coccinelle" the VW .

But back to what is interesting here.

I intend to make a bigger Scott/ Ossie / pancake / Lynch/  motor to power my Ultralight flying machine .

Untill now the best one i got is the Geiger motor with a 90 % efficiency   very high   do you think we can do better with the Scott.

What seems to be good is that we could use a greater diameter so more torque and perhaps more accuracy from the coils pulse and BEMF recup.

What i need  to work on , is 15 KW at 1200 rpm   with basic lipo battery at 56 volts (or more ) and 40 ah.

What do you think ?

rergards

Laurent

[woopy]

Hi Greg

Yes i have already mounted different electric motors on my ultralight. It works great.

The last one is a Geiger ( www.geigerengineering.de) motor (see picture) it is a outrunner of 10 kw which spins in direct drive a 1.25 meter prop and produce about 54 kg thrust at 1750 rpm. the motor weight is 3.7 kg  very light.

The battery is a lipo 56 volts (14 elements) and 40 Ah that weights 16 kg so the total weight of motor  and controller and battery is about 20 kg for about 20 minutes flight.

My aim with my research is to find an easy to build very torquy and light motor that spins the same prop diameter for the same thrust but at 1200 to 1500 rpm. Because the problem is the noise of the prop tips. The lower , the silenter. And electric flight must be perfectly silentfull.

That's why i am looking for a bigger diameter motor.

With my Ossie sandwitch motor (small replication) i am testing  that.

On each of the sandwitch rotor there is pairs of magnets glued on a piece of soft iron to get more flux. Than the air core coil is pulsed  between the pair of magnets, so i get 2 propelled magnets (upper and down sandwitch rotor) and 2 repelled magnets simultaneously. So for one pulse there is 4 magnets in motion. Seems to work well on my small model. I don't know if this config could diminish the Lenz resistance ?

Now there is to scale up the motor, choose the magnets and coils and driving electronic for pulsing and BEMF recup and so on ... and why not get really high efficiency      a lot of work.

What i find good with the Scott motor is the offset of coils to magnets so the motor will work very smoothly.

I will think about it how i can arrange my magnets to get a smooth running.

So a nice project and thanks to bring your ideas

regards

Laurent

[solinear]

Hi all,

Has anyone heard of or know if this motor is being discussed anywhere?  I know this guy but haven't heard from him in years ... I think he hates me.  He built one of his early motors in my shop a couple of decades ago. 

WOW! Nice to see he got a patent on it.  It issued May 7, 1996.  It looks like it's still in force ... cool!

From the Patent:
http://02d1852.netsolhost.com/plasma/goss1.jpg

Anyway this is the patent number for his motor:
5,514,923

Get it at the USPTO's website.

You'll need the compatible TIFF plugin like AlterniTIFF to view all of the patent pages (images):
http://www.alternatiff.com/

Here's the USPTO's link:
http://www.uspto.gov/

Here's the USPTO link to his patent:
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PTXT&s1=5,514,923.PN.&OS=PN/5,514,923&RS=PN/5,514,923

The site is free.  The plugin is free.  You can download the patents for free ... only problem is the "free" TIFF plugins only allow you to save one page at a time ... SO WHAT ... free is free and that's worth a little time waiting.  I know I've been told my time isn't worth SQUAT ... and I believe it.

Fun.  Cheers,

Greg

Been there, done that - it wasn't a very efficient design.