Might be a dumb question......PROPS

[topfuel443]

Hey guys this might be a dumb question and maybe im missing something obvious. I was measuring all of my two blade props last night (diameter) with vernier calipers across the widest part (usually at the tips), Well I have a few good three blades that I use also, how and the heck do you measure three blade prop diameter ?

Also I have been using a hughey prop pitch guage (didnt come with instructions when I bought it) . what size step does every one use when measuring pitch? How do you acurately measure pitch of a prop when one measurement at the tips are completely different numbers than whats closer to the drive dog. the numbers im coming up with are usually lower than what the mfr. states the prop should be no matter where i measure the prop. Am I doing something wrong?

Ive just started doing my own props and dont have a problem sharpening and balancing, but when I want to repitch or add/remove cup How do I know where I should put add or remove it according to the pitch guage? Not trying to get to technical but just curious about a few things

~ James

 

[PondSkimmer]

Why cant you just measure the radius from the middle of the prop shaft to the outer most edge of 1 blade then double it ???

As far as the prop tool i have no idea never used one

 

[topfuel443]

Guess I could, I have been measuring them off of the boat so I would have to guesstimate where the propshaft center would be, Or i could just go to the outer edge of the prop shaft I.D. to the edge of the blade then add half the diameter of the I.D. in the center of the prop. just curious how everyone else did it.

 

[Ron Olson]

I bought one of those, it did have instructions and still couldn't figure out how to use it! Sold it to somebody else to mess with. Once you figure out how to use it, you'll find out all kinds of interesting things about your props such as how far off the blades are from each other.

 

[topfuel443]

Ron, I know the general Idea of how to use now, but was wondering if theres a secret to to the numbers that the factory is giving out. Your right, I wont mention any mfrs. but some of these props that im paying big money for, are as much as 8 degrees off per blade right out of the package! It is good for making sure the prop baldes are of equal pitch, and thats about the only thing i have been able to use it for myself. thanks ~ james

 

[waterbug]

James

Randy has a Hughey prop gauge !! he'll give you a copy !!!!

I went by there today and met Karla !!! She said she was ready to whip your butt some more in .21 hydro !!!!! ;D It's a totaly different atomsphere in the shop. They told me go behind the counter and get what you need !!!!! ;D She's pretty KOOL !!!! We even had Randy cutting up and smiling

P.S. I had to stir trouble

 

[MikeP]

I have heard and been measuring 70% out from the hub.

From the TE of the blade just before it falls off and sitting on the step gauge, pointer on 0 deg. rotate the prop and set it on the next step up. Should be around 10 deg. depending on the cup. I found that this matches props that I have bought. The hard part is reading the degrees less that 1/2 deg.

The spread sheet I use has inputs for 1 step .1275" and 2 steps .250"

-MikeP