New prop out of balance. Where's this gonna go?

[Don S]

Re: New prop out of balance. Where's this gonna go?

Perhaps he doesn't want to take a chance on damaging his drive/outboard with an unbalanced prop? I know I wouldn't.

Come on, you start out slow and speed up. You aren't going to get that much vibration even if it does vibrate. This is not a high rpm prop on a race boat. I would bet money 99% of the props sold are out of balance a little, and never causes a problem. You guys are just over thinking it without knowing all the facts.

Even the Prop manufacture said put it on the boat and try it and isn't expecting a vibration.

 

[Don S]

Re: New prop out of balance. Where's this gonna go?

I guess there is no vibration, at least not mentioned in this thread. http://forums.iboats.com/showthread.php?t=581096&p=3998549&viewfull=1#post3998549

 

[jestor68]

Re: New prop out of balance. Where's this gonna go?

Mount the prop(properly torqued) on the drive.

Run it at 1500 rpm in gear (on the muffs).

Carefully place your fingers on the rear of the drive(above the av plate).

You will "feel" any excessive vibration.

For a point of reference, run it first with no prop on there.

This simple test is the first thing I always do to a prop. You'd be surprised how many don't pass.

 

[Mule Laker]

Re: New prop out of balance. Where's this gonna go?

Mount the prop(properly torqued) on the drive.

Run it at 1500 rpm in gear (on the muffs).

Carefully place your fingers on the rear of the drive(above the av plate).

You will "feel" any excessive vibration.

Good idea.

Guys, I didn't run this prop right out of the box. I balanced it first. I'm not an expert and find a propeller difficult to balance perfectly. Mainly because you are removing weight, not adding. It's really, really close on the stand and felt smooth on the water this last weekend. You are right Don.

My prop selection/evaluation is going on the back burner though until I clear some other things up first. See my other thread.

http://forums.iboats.com/showthread.php?t=581096


jestor, there are cones with tiny set screws on the rod. They are hidden by the prop.

 

[emilsr]

Re: New prop out of balance. Where's this gonna go?

Mount the prop(properly torqued) on the drive.

Run it at 1500 rpm in gear (on the muffs).

Carefully place your fingers on the rear of the drive(above the av plate).

You will "feel" any excessive vibration.

For a point of reference, run it first with no prop on there.

This simple test is the first thing I always do to a prop. You'd be surprised how many don't pass.

That's a good idea for those that don't use a balancing rig; certainly better than the mfg. recommendation just to run it and see what happens. On the OP's bowrider, that prop is rotating 47 times per second at WOT or about 4 times as fast as the tires on your car going 60mph. Not a direct comparison, but you get the gist of it. Balance matters, even if it isn't a race boat.

 

[Faztbullet]

Re: New prop out of balance. Where's this gonna go?

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.

 

[phillnjack2]

Re: New prop out of balance. Where's this gonna go?

Quote
Phil, mate, chill just a bit. Go take some pliers, bend one blade over, )

No im talking of a blade not being the same shape as the other two, not a bent prop !!!!!
out of shape and bent are two totaly different things.
Out of shape can be one blade being more rounded than the other two etc.

sounds like were talking of two different subjects,so ill let you get away with that one ha ha .

I like the pic of the prop balancer, identical to the small ones used for rc boats and planes and car wheels.

These are easy to make,


phill