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Discussion Starter · #1 ·
I'm working on adding some forced air flow to my motor and I'm wondering if
anyone knows how much air (cfm) the built in impeller moves. I want to make
sure I provide enough cooling for low speeds but not impede the existing
airflow when it's up to speed. I'm also thinking of adding four smaller
fans, one per brush opening instead of one large fan with ducting around the
whole brush housing. I do have a bit of a clearance issue, so whatever
manifold I make will only have about an inch of clearance above the motor in
one spot.

Any thoughts on the issue would be appreciated.

Thanks

Dave Cover
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Discussion Starter · #2 ·
Hello Dave,

At one time, I have my Dayton 6 inch blower fan that also had a 6 inch carb
air cleaner, remotely mounted on the front radiator cross support. A
aluminum 3 inch tubing was first bent with a thin wall conduit bender then
was roll flat to about 1 inch thick with a sheet metal shop rollers so it
would lay nice on the inner fender.

A short length of this 3 inch tubing was also curve to fit the radius of the
motor and also roll flat. One end was cap and the other end was connected
to a length of 3 inch air hose that was left somewhat un-expanded, not
expanded all the way out. A square hole was cut in the brush cover and this
short length of flatten 3 inch tubing and was bolted to the brush cover
while the brush cover was off the motor.

It is best to tapped the brush cover so there is no nuts expose inside the
housing. I use short 3/8 or 1/3 inch long 10/32 hex head screws that was
inserted through the inside of this duct which threaded into the brush
cover. To turn the this screws, they are only place about 3/8 inch from the
edge of the cut out and you can get them started with you fingers. Use one
of those ratchet 3/8 inch box wrenches to tighten up.

You could use a socket drive wrench by drilling a bolt hole all the way
through this curve flatten tubing and insert four aluminum guild tubing for
the 10/32 inch bolts. Make the tubing flush with the top of this tubing and
your bolts are now longer to go through this duct work. I fine this was
best, because I can use a washer and lock washer on the outside instead
inside of this duct, where they could become loose and fall into the motor.

Later, when I remove the front battery box and combine all the batteries in
the middle of the EV, I was able to mounted this fan directly on the brush
cover of a Warp motor. A curve steel bracket was made to fit over the
screen cover which has a 1/8 inch rubber gasket between the screen and the
cover. This curve bracket was made from a segment of a 10 inch tubing and
had tabs weld on it which extended down the front of the motor and bolted to
two of the bolt holes that are tapped on the front bell.

Roland




----- Original Message -----
From: "dave cover" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, October 09, 2007 6:22 AM
Subject: [EVDL] ADC 9 air flow requirements


> I'm working on adding some forced air flow to my motor and I'm wondering
> if
> anyone knows how much air (cfm) the built in impeller moves. I want to
> make
> sure I provide enough cooling for low speeds but not impede the existing
> airflow when it's up to speed. I'm also thinking of adding four smaller
> fans, one per brush opening instead of one large fan with ducting around
> the
> whole brush housing. I do have a bit of a clearance issue, so whatever
> manifold I make will only have about an inch of clearance above the motor
> in
> one spot.
>
> Any thoughts on the issue would be appreciated.
>
> Thanks
>
> Dave Cover
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter · #3 ·
Hey Dave

As a motor guy it's info I'd like to know as well.
This, like brush timing is going to be different for
each user, IMO. I really don't have any way of
measuring air flow though. In general adding a blower
will increase the motors duty cycle. Overkill for
some but needed for others. WZ shares just one fan
for two 8's, but it's a light car with lots of motor
and batts to feed them.
Hope this helps

Jim Husted
Hi-Torque Electric





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Discussion Starter · #4 ·
Hi Jim and Dave,

The more the better. Not too scientific, but my
opinion. I am not aware of any quantifiable data on
the subject. I feel that an automotive heater/AC
blower is a good choice. Usually they are a 12 volt
motor with a cage fan and shroud which can be ducted
to the motor. You always want clean air. A coarse
filter can be used.

I have heard of some guys that remove the motor's
shaft attached fan when using the blower. I don't
think that is necessar. It adds a degree of
redundancy should the blower fail.

Regards,

Jeff M


--- Jim Husted <[email protected]> wrote:

> Hey Dave
>
> As a motor guy it's info I'd like to know as well.
> This, like brush timing is going to be different for
> each user, IMO. I really don't have any way of
> measuring air flow though. In general adding a
> blower
> will increase the motors duty cycle. Overkill for
> some but needed for others. WZ shares just one fan
> for two 8's, but it's a light car with lots of motor
> and batts to feed them.
> Hope this helps
>
> Jim Husted
> Hi-Torque Electric
>




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Discussion Starter · #7 ·
From: dave cover
> I have a double squirrel cage fan that I bought for the purpose, but
> creating the duct work was becoming a problem. So I've been toying with
> using smaller fans, 2 per brush opening on my 9" ADC. I figure it might
> be easier to build small manifolds to hold the little fans.

By small fans, do you mean propeller fans? If so, you will find that they move a negligible amount of air when faced with the back pressure caused by the tight twisty passages through a motor.

For motor cooling, you'll have much better success with a squirrel cage or centrifugal blower. They can move significant amounts of air even into a high back pressure.

--
"Excellence does not require perfection." -- Henry James
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

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