Pitch Gage

[Robert Zambelli]

When the gage is used, where is the actual pitch measured?

I'm curious since the pitch obviously decreases as the measured value moves toward the tips.

For example, on a 10-6, where along the blade is the 6?

  Bob Z.

[Bob Reeves]

Like the Prather, you read the dial that corresponds to the station location. Easy to see if you have a Prather but hard to explain

[Clancy Arnold]

I have attached a picture of my Hooptee Pitch Gage.  I extended the size to allow me to check up to 15 inch props.  To read the pitch the top edge of the moveable pointer must be just touching the back side of the prop blade the full width of the blade.  The slots in the base are lettered and indicate which vertical column to read for the pitch. This design allows you to measure the pitch in several locations along the blade length.

Search "Hooptee" on this forum for information.

Clancy

[GGeezer]

When the gage is used, where is the actual pitch measured?

I'm curious since the pitch obviously decreases as the measured value moves toward the tips.

For example, on a 10-6, where along the blade is the 6?

  Bob Z.

If the pitch angle distribution is ideally helical, the 6 is all along the whole blade. Most props stray from the ideal and there is some evidence that certain non-helical distributions can be more efficient. I usually measure the angle at 75% out from the axis and then do the calculation of the actual pitch.

Orv.

[Howard Rush]

A propeller is not a screw going through cheese.
                                                      Chris Machin

[Steve Helmick]

When the gage is used, where is the actual pitch measured?

I'm curious since the pitch obviously decreases as the measured value moves toward the tips.

For example, on a 10-6, where along the blade is the 6?

  Bob Z.

In theory, it will be 6" pitch for the whole blade. In actual fact, it may not read 6" pitch anywhere on any of the blades. Cheese is over-rated, IMO.  Steve

[Brian Massey]

I've been told that the last two inches of the prop is where most of your thrust comes from. When I re-pitch a prop, that's where I concentrate. Right or wrong?

BTW, cheese is our friend.

Brian

[Steve Helmick]

I've been told that the last two inches of the prop is where most of your thrust comes from. When I re-pitch a prop, that's where I concentrate. Right or wrong?

BTW, cheese is our friend.

Brian

I'd guess that the last 2" or 3" is most important for STUNT. No idear (sic) about other events. I pitched up my BE red (undercambered) 12 x 3.75 (that had been clipped to 11.5" for the .46VF) from what I read as 4.25" pitch full length to 4.75" at stations 8, 10 & 12, and had magical increase in line tension and a drop of about 200 rpm at launch. It ran richer, which I think also helped. One of my goals was to increase fuel burn to an even 6 oz, instead of somewhat under that, like 5.5 ~ 5.75 oz.  Then, I buzzed that prop and get to try again. Havarti is the best cheese. "American Cheese" is bogus cheese, and to be avoided.    Steve