Pitch gauge

[Terry Keeley]

If you have 6" at 15 deg how much do you have from the 15 to the traling edge?

7.2 or more?

I run different amounts of cup (progression) but like to stay within an inch or so of the LE. So the last 15* at the TE would be about 7" on this prop.

 

[dwilfong]

You should run at least 20% or the water will not stay on the blade.

May be higher pitch and speed run different.

But then again may be you are just running to much lead in and not enough progression to keep it hooked up.

24000 is not much RPM for high speed running. less lead in and more RPM may be the ticket.

Hard to push that much lead in from what I have seen.

Less slip with smaller lead in and 20% progression with just enough cup to load the eng has work good for me so far.

I do not count cup in the progression. I use the last 5 deg for just the load adjustment.

Now this is with the new ABC prop with the woop on the trailing edge.

 

[Tom Foley]

It can't be 0 % slip

 

[dwilfong]

Yes it can if you use the lead in pitch as the constant and work the prop right.

Total pitch will never be 0% slip I will give you that...................................................................

You have to work around a constant or you have no reference.

You will just spin your prop in circles..............LOL

 

[Terry Keeley]

You should run at least 20% or the water will not stay on the blade.

May be higher pitch and speed run different.

But then again may be you are just running to much lead in and not enough progression to keep it hooked up.

24000 is not much RPM for high speed running. less lead in and more RPM may be the ticket.

Hard to push that much lead in from what I have seen.

Less slip with smaller lead in and 20% progression with just enough cup to load the eng has work good for me so far.

I do not count cup in the progression. I use the last 5 deg for just the load adjustment.

Now this is with the new ABC prop with the woop on the trailing edge.

How exactly are you calculating "20% progression"?

 

[dwilfong]

Well I just add 20% to the lead in. so a 6" would be 7.2" from the 15 deg mark to the start of the cup or the woop as I call it on the ABC props.

that is why I map the prop taking readings every 5 deg on the gauge. you can then compare different sections on the prop.

say you calculate every 5 deg move then every 10 deg then every 20. or start at the 15 deg from the lead in and see what the center is.

You can relay see what the blade is doing any where on the prop.

How much dose it progress every 5 deg or every 10 deg or every 15 deg you get the idea.

I don't know if this is right or wrong just how I learn a prop and make changes.

 

[Terry Keeley]

Cool...