009 One blade.jpg

Hydro 21 prop that throw a blade, engine was turning some serious rpm.

how did that happen???

brett english said:

how did that happen???

Click to expand...

Boat was running at approx 75mph when I heard a oscillating sound in the turns, and when I brought the boat in, this was the cause.

This is the second prop in one week that has thrown a blade.....I guess that rpm has increased!

Jorgen

This is a link to one of the runs the day the above prop throw a blade.



Jorgen

Hello Jorgen, watched video of your .21 hydro. Motor sounds great. What motor are you running? Richard D

Richard Dahlheimer said:

Hello Jorgen, watched video of your .21 hydro. Motor sounds great. What motor are you running? Richard D

Click to expand...

Hello Richard

Pm sent.

Jorgen

Jorgen Andersson said:

brett english said:

how did that happen???

Click to expand...

Boat was running at approx 75mph when I heard a oscillating sound in the turns, and when I brought the boat in, this was the cause.

This is the second prop in one week that has thrown a blade.....I guess that rpm has increased!

Jorgen

Click to expand...

are you heat treating your props? this would explain it..are you the one who purchased that prop brand new?

brett english said:

Jorgen Andersson said:

brett english said:

how did that happen???

Click to expand...

Boat was running at approx 75mph when I heard a oscillating sound in the turns, and when I brought the boat in, this was the cause.

This is the second prop in one week that has thrown a blade.....I guess that rpm has increased!

Jorgen

Click to expand...

are you heat treating your props? this would explain it..are you the one who purchased that prop brand new?

Click to expand...

Hello Brett

Yes, both these props was new when I bought them. I have worked on them myself and one of them was heat treated.

The one in the picture has not been heat treated.

What are your experincies around this?

Jorgen

Jorgen,

It looks like some of my personal collection propellers.

They will go over 80 MPH with the right set up. I quit

making them for others because of the liability involved

when they throw a blade. The only way you will get them to

not break is make them out of Stainless Steel like I did.

It is a great profile on a 21 Hydro and soon to be tested

on my 12 Hydro. Was that an S-15 Jorgen?

Thanks,

Mark Sholund

Props-4-U

231.590.3023

Hi Mark

Thanks for nice words.

I am very happy with the performace of the props I have modified myself.

Some have worked porly, but I have 3-4 that are really interesting.

I am not a prop guy, like you or Andy, but I felt that I had come to a point with very little development on the props for me.

I did run 81mph with this and in a boat that is old and a bit heavy, 2050 grams. It has been modified several times, so that is the reason for the extra weight.

Yes, you are probably right, if using more aggressive blade profiles like this, new, stronger materials will be needed.

Yes, the prop in the picture started it´s life as a S15.

Can you please send me all the 21 Hydro from your personal collection? *smile*

I will do some serious testing the next 4-5 weeks, maybe I could be of some help?

Time for dinner

Jorgen