Propeller Balance Master

[Casey Curtis]

Has anyone used the propeller balance master and have you had good success?
I would like to try one on a pusher 912 with a two blade prop. I can't seem
to get the owner at www.balancemasters.com to call me back and answer my
questions. Any input sure would help.

Thank you

Casey

[Richard Lamb]

If it's a wood prop it will likely have a center hole.

A balance tool for that is fairly easy to make.

Find / machine an aluminum round to fit the hole and
bore a center hole in the round for a 3/8" dia steel
rod (axle).

Put the plug in the prop and poke the rod through the
plug.

I used my open vice jaws for a balance fixture.
Worked swell.

[abripl]

Richard,

Take a look at the www.balancemasters.com website. They do not sell
balancing machines for balancing whatever. They sell a product that
attaches permanently to the prop or other wheels - big 18 wheeler
trucks are using them - and automaically provides balance to the
rotating disc. It is a unique device that has a ringed tube of mercury
and the motion of mercury provides live balance to a rotating object.

If anybody has used one of these things on their prop please let us
know what success you had.

[Montblack]

("Richard Lamb" wrote)
> If it's a wood prop it will likely have a center hole.
>
> A balance tool for that is fairly easy to make.
>
> Find / machine an aluminum round to fit the hole and bore a center hole in
> the round for a 3/8" dia steel rod (axle).
>
> Put the plug in the prop and poke the rod through the plug.


You lost me here. How far does the rod stick through? Does it matter?

I have no idea what's next. Where does the balancing take place? How?

Having a tough time trying to visualize how one balances a wooden prop using
a rod.


Montblack
No clue how a person balances any prop.

[Morgans]

"Montblack" > wrote>
> Having a tough time trying to visualize how one balances a wooden prop
> using
> a rod.

You open your vise, so it is wider than the thickness of your prop, at the
flange. Then, rest the rod on the vise, with the prop, in the opening.
Orient, or roll, the rod/prop assembly until the blades of the prop are
horizontal, then let go. The heavy end of the prop drops. Add paint, shave
prop, or do whatever your favorite method of changing the weight of the
prop, until it stays horizontal when you let go of it.

Do the same thing with the prop vertical. This corrects for the
leading/trailing edge balance. Re-check the horizontal. Re=check the
vertical. Recheck..........

The only thing that this will not fix is the fore-aft balance. Not a great
big deal, if the prop is reasonably well made, to most people.

Cautions. Make sure your rod is really, really straight. Make sure your
vise is really really level. Make sure the rod holder is really in the
middle of the thingie you put in your prop hole. Make sure your vise does
not have all kinds of nicks and dings in it (like mine).

You can also go one step better, and make a thingie to clamp in your vise
with sharp edges, like old (non nicked (yeah, right)) jointer knives. That
way, you can get rid of the factors of the out of level, bashed up vise, and
get a lower friction (because of the sharpness) rolling surface.

An alternate balancer can be made if you have a lathe, if you make a thing
like a lawnmower blade cone, by turning a blank to fit into your prop hole,
then center bore it all of the way through a little past the other side of
the prop. Place a sharpened rod into the hole, with a bit of slop around
the sides, so it will teeter back and forth when the prop is placed on it.
When your prop is level, your prop is balanced.

Of course, if you have not balanced your spinner, you have just wasted a
bunch of time. <g>
--
Jim in NC

[abripl]

Does anybody have experience with the BalanceMaster device? It is not a
balancing machine.

You people are talking about a different subject altogether.

[Montblack]

("Morgans" wrote)
> Of course, if you have not balanced your spinner, you have just wasted a
> bunch of time. <g>


I've used a tripod bubble balancer for car tires, in the early 80's.

So as not to end up with the table sitting on the floor with four stubby
legs, what's best - shaving or painting? How far out from the hub for each
method? ...assuming a wooden prop.

Just curious.


Montblack

[Morgans]

"Montblack" > wrote

> what's best - shaving or painting? How far out from the hub for each
> method? ...assuming a wooden prop.
>
> Just curious.

The further out, the less weight needs to be added. I have read that it is
far better to not disturb the seal of the prop by shaving, if at all
possible. It may not be possible to change a badly off prop with paint
alone.

Others have opinions reflecting far more experience than me. The largest
prop I have ever balanced is 22 inches, but it does make a huge difference.
--
Jim in NC
--
Jim in NC

[ELIPPSE]

A machinist friend of mine made an incredible prop balance checker for
me. It consists of a 6" long metal tube connected to a 4" diameter,
1/8" thick disc that has another disc, 1/2" thick attached to it. The
smaller disc is of the diameter that fits snuggly into the bottom of
the prop, and the larger disc butts against the bottom of the prop. A
1" diameter x 1" long fitting is turned on a lathe, and bored 3/4" ID
to within 1/4" of the end, and another bore follows of 5/8" ID to
within 1/8" of the end. This 1/8" closed end is drilled in the center
about .02", and then sliced/turned off. This creates a 1" dia x 1/8"
thick disc that is concentric with the fitting. A second 1/2" long
fitting is made that fits snuggly inside the 1" tube and also has a
..02" hole drilled through it. The tube with the attached discs is
inserted into the back of the prop. A thin piece of cable is threaded
through the disc and first fitting, then the second fitting then down
through the 6" tube and the cable secured on the bottom discs. The
second fitting is pushed down into the 6" tube until it is just above
the fore-aft center of the prop, then the first fitting and its disc is
placed over the top end of the tube. Now the cable is used to suspend
the prop. The turned-off disc on the top of the first fitting acts as
an indicator of out-of-balance of the suspended prop. If the prop is
balanced, the turned-off disc will be concentric with the fitting just
under it. Any out-of-balance will cause the disc indicator to be
off-center. The fitting inside the tube, which holds the cable in the
long tube's center, adjusts the sensitivity. When it is above the
prop's fore-aft CG, the sensitivity is low. Pushing it further and
further down into the tube toward this CG, the sensitivity gets greater
and greater, until when it is below the CG, the prop flops over to one
side. When adjusted for good sensitivity, it will show the unbalance of
a #4 washer at the tip of a 63" diameter prop. The indicator disc has
its maximum deflection in the direction opposite from the unbalance. It
shows unbalance in all directions. Try it; you'll like it! Paul

[Morgans]

"ELIPPSE" > wrote

>A machinist friend of mine made an incredible prop balance checker for me.

That is a keeper! Thanks.
--
Jim in NC

[ELIPPSE]

I'm going to write an article for Contact! magazine describing how to
build one of these balancers with included drawings (one word is worth
a thousand pictures, or something like that!). I just used mine today
to balance my three-blade which I recently painted one blade white, one
red, and one blue! I balanced it by spraying on more paint front and
back on the lighter blades. It's nice to be able to spray away your
unbalance! The balancer is so sensitive you can watch the balance
slightly shift as the paint dries!