Propeller Balancing
Balancing is the final step in the physical repair before the cosmetic
finish.
There are four basic type of unbalance: Static, Kinetic, dynamic and whip.
Propellers are balanced using Static or Dynamic means.
Static unbalance is gravity at work. If a propeller is placed between centers on
frictionless rollers the heavy or weighted portion will rotate to the bottom
immediately. This is corrected by adding or removing weight from the propeller.
Dynamic unbalance is a twist caused by two forces in two separate planes. If
weights were placed 180 degrees opposite the other, no single point would roll
to the bottom, because the prop would be balanced both statically and
kinetically. By rotating the propeller at an appreciable speed each weight would
cause its own centrifugal force in separate planes. This would cause an end to
end rocking motion. Vessels operating at higher accuracy using propellers of
class one or class S ISO 484/2 should be dynamic balanced using ISO 1940 G2.5
balance tolerance.
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Dyna-Bal Dynamic Balancing
Rundquist Propeller Tools has teamed with Dyna-Bal to provide state
of the art dynamic balancing machines to the marine industry. We are the
exclusive world wide marine distributor for Dyna-Bal.
Dyna-Bal Floor Model machines are designed for rugged use, yet are
super-sensitive, easy and simple to operate. Overhung balancing of
propellers is made simple with Dyna-Bal's standard equipment overhung
balancing adaptor.
Quick, easy height adjustment to compensate for different size bearing
surfaces make end thrusters obsolete. Balance rotors in their own
bearings or with one bearing and on one journal.
Dyna-Bal machines automatically compensate for uneven floors - no
special floors or foundations are required. Dyna-Bal machines are not
bolted down (anchored) to the floor. This makes extending the subbase
fast and easy.
The subbase has been manufactured in two sections allowing them to be
extended beyond rated bearing centers. This allows you to balance
rotating parts that are longer than your subbase.
Price $25,000 - Model D-015 with arbors. Setup and
training is included at your facility located anywhere in the
continental United States.
Click here to calculate your
Return on Investment
for the Dyna-Bal
Click Dyna-Bal Presentation (5.35Mb) to
download a presentation of this balancer in use, including sample screen
views of the software system.
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This presentation is in Adobe PDF format and requires Adobe Acrobat
Reader to view.
For more information about PDF files or to download Acrobat Reader,
click here.
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Static balancing
of a propeller is very important and is not too
difficult to achieve. After grinding the welds down and shaping the blade to the desired
diameter follow this procedure.
1. Mount the propeller on the balancing arbor.
2. Place the propeller on the balancing fixture.
If the prop
is out of balance, the heavy blade or blades will swing down.
3. To remove excess weight on the heavy blade or blades, use
a grinder and 80 grit discs or belts, and grind on the negative face of
the propeller. Be careful to avoid grinding the edges and concentrate on the center of the
blade. Do not remove metal from the edges or diameter of the propeller.
4. Repeat this procedure until all blades remain
still-regardless of what position the prop is turned.
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