Are Props Balanced?

[retiredfornow]

Seems they should be. I have a spare stainless 3 blade prop that had a crack about 3/8" from the end of one blade. Being bored, I took a side grinder and ground off the end till I had the crack removed, then shaped it so it looked good. I then made a paper templet of it, marked the other 2 and ground them off also. Got to admit, looks pretty good, don't know how good it is now for propulsion. Do prop shops balance props? Just curious. If this one doesn't work, I'm gonna throw it away someday. I knewI should have kept my TIG welder!

 

[Wingnutt]

Re: Are Props Balanced?

Yes, props are balanced, and yes a good prop shop can balance them.

 

[craze1cars]

Re: Are Props Balanced?

Yes. The less advanced prop shops and some at-home people like yourself just static balance them. The good prop shops invest in the proper equipment to dynamically balance them.

Much like a tire on a car. Some shadetree mechanics use a bubble balancer to get it "close". A good shop uses its dynamic balancer to really get it right at spinning speeds...

Random web example that describes it all better than I can:
http://www.rundquist.com/how_balancing.htm

For about $150 you could have had that prop professionally crack repaired/polished/balanced/good as new at most prop shops. And a good prop shop can probably still save it despite what you've done to it. if you've taken 3/8" off each blade you've substantially changed how it will cut thru the water, and probably changed the effective pitch...and, of course, the balance. Running an unbalanced prop can get very expensive if it vibrates your lower unit apart....

 

[retiredfornow]

Re: Are Props Balanced?

Thanks for all the info! The prop is a 19 pitch, came with the boat, and I run a 15 pitch. I can't really use the prop anyway, just a spare ...just in case. That's why I ended up with a 2 1/2 car garage that you couldn't get a car in. Hoarding junk, just in case. LOL...Thanks again.

 

[Texasmark]

Re: Are Props Balanced?

Try it, got "nuttin" to loose. If it runs smooth, go for it, otherwise follow directions and if it vibrates, shut her down and go home. I think you did the right thing personally and the slower the prop turns the less the impact of some imbalance.

My, 2c
Mark.

 

[retiredfornow]

Re: Are Props Balanced?

Just to update this, I tried the prop out today and it worked fine. No vibration that I know of. Now I have a good spare.

 

[Fisherball]

Re: Are Props Balanced?

Is a bear Catholic?

Does the Pope **** in the woods?

Whe I first got my boat the prop had small pieces missing & didn't vibrate at all. Next season I had to replace LU seals & the prop shaft gear had a small chunk missing. Over 3 more seasons the chunk got much bigger. Every time I changed LU lube there would be metal pieces in the old lube that became progressively more numerous the more I used the motor.

 

[Fed]

Re: Are Props Balanced?

Therefor props without missing pieces will vibrate which will stop chunks falling off your gears.

 

[Texasmark]

Re: Are Props Balanced?

I've seen a lot of dinged up props on a lot of boats and you can't tell me they are balanced and you never (once) heard of a lower unit "chunking it's parts". But, what the heck. If it feels good do it. Find a prop shop and have them check it.

Mark

 

[vaelors]

Re: Are Props Balanced?

I agree to you! props are balanced!