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Re: [EVDL] 9" adv Aluminum feild coil housing ?

Hi Jeff,

Milling channels or grooves across the length of the
frame will increase the reluctance of the back iron.
In other words, screw up the magnetics. Result will
be decreased torque per amp. There are certain areas
of the frame more critical than others. So if you
carefully removed material in the right spots, effects
on performance would be minimal. This might require
more of an artist than a machinist.

This is quite difficult to explain without drawing a
picture. And I can't do that in this format. Perhaps
you can find something on a web search or in a text
book. A 3D magnetic finite element analysis diagram
of the field structure would be perfect.

IMHO it is a lot of work for a small gain. Removing
excess electrolyte from the batteries might be more
fruitful :). Or swap your big 9" for a smaller
motor.

Jeff M.


--- Jeff Mccabe <[email protected]> wrote:

> Thanks for your reply Jim,
> Seeing how you need the ferrous material for the
> motor to work properly. How about if you make Ball
> end
> mill channels, say half the thickness in depth along
> the length of the motor circumference ? (o.d) This
> way
> your just remove access material but still have the
> original body ?
> Yes you could remove to much and weaken the
> housing,
> but you and other motor builders do remove material
> from the outside and don't appear to have problems ?
> I don't know.....just ideas. I have a road racing
> background, so this should explain my weight
> obsession.
> To date I have removed well over 1,400lbs from my
> Porsche already and have my eye on another 150-200.
> Thanks,
> Jeff McCabe
>
>
>
> --- Jim Husted <[email protected]> wrote:
>
> > Hey Jeff, all
> >
> > I got Jeff's and then Lee's reply to this before I
> > got
> > the actual post. As they pointed out, it's part
> of
> > the motor you got to live with. Reminds me of the
> > song "He ain't heavy... He's my motor.. lol.
> >
> > Lansing Bagnall actually makes a motor with an AL
> > housing. They set the field coils into a
> laminated
> > steel core that inserts into the outer AL housing
> > shell. Laminating allows you to do more with less,
> > but
> > not that much more.
> >
> > I've also seen an almost all AL aircraft starter
> > where
> > just the poles, arm body, bearings and shaft were
> > steel. Almost threw my back out as it looked like
> > it
> > weighed 80 lbs and wieghed only 35 lbs or
> whatEVer.
> > The problem with AL field coils is attaching it to
> > the
> > terminals, and is a major weak link area on EVery
> > style I've seen to date. It was also as Lee
> stated,
> > high RPM's low torque.
> >
> > I've thought about what it'd take to make a
> > laminated
> > housing with a lightweight strong skin to hold it
> > tight and true. In the end, if it were that much
> > better then it's how it'd be done. What's one
> > willing
> > to pay for a percent or two? To create a new
> > housing
> > for let's say a 9'er and to compare would be a fun
> > thing to try, if one has the time. Anyway that's
> my
> > take on it.
> > Cya
> > Jim Husted
> > Hi-Torque Electric
> >


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