Pitch angle different along the blade?

[arne997]

My Hurry 550 RCP/ Gaui carbon blade doesnt have the same angle when I messure it?
With center stick I have -2 deg in the root, 0 deg in center and + 1 deg most far out of the blade.



With the wooden blade I have -2 deg all the way.

Should I make any adjustments when flying with the carbon blade? They fly good.

Thanks

[bugdozer]

My 500mm RCP blades are fine but in the first round of 325mm blades for the T-Rex 450, several people reported warped blades. I am running RCP II on my T-Rex now and are straight and stiff but RCP's quality control could use some work. Balance is spot on but one blade looks great while the other has dimples in the finish and some exposed carbon fiber on the trailing edge but for $19.00 they can't be beat.

Regardless, I would not fly with a blade that warped. If they are new, I would contact the seller and see if you can get a replacement set.

[arne997]

Anyone with Gaui RCP blades and info on those different angles along the blade?
Seems like they are produced a little bit twisted.

Thanks

[michael88997]

i have a pair of them and they are fine... make sure your keeping the same distance away when your measuring because it could look different... just lay them on the table and see if their warped because 1 degree would be noticable on the table...

[arne997]

If I put mine on the table it looks fine, but when I messure them up I see 3 deg diffenence.
I have got replyes from other that didnt know about this untill the took a pitch gauge and checked it and found the same 3 deg diff.

[michael88997]

thats weird... i havent checked mine because my guage broke but mine fly great... i would just see how they fly

[arne997]

Mine fly good, probably nothing wrong. But inverted flight must be a little different.

My problem is that I dont know were to messure th 0 deg pitch? mid pos or most far out.

To see this 3 degree difference you need the pitch gauge, I cant see the difference with the eye.

[michael88997]

yea well i have my pitch curve at 0 50 100 and at midstick its at zero pitch

[arne997]

0 pitch is the question, where do you take that angle from?
From the inner part of the blade or the outer? Where do you put the gauge?
The blade is 3 deg twisted.

[michael88997]

i always put it on the tip of the blade right were it gets wide... so pretty much on the wide part of the tip, i normally also put the blade over the tail blades and put my head right there so i know im always around the same distance...

[xodarap1]

No matter where you measure zero pitch from, when you track the blades you will adjust one blades pitch to match the other anyway so I doubt the little bit will make much difference in the end. Besides, you can adjust the pitch curve to make it where you want it to be to compensate if it isn't perfect at mid stick in flight. If it was me that had a twisted or warped blade, I would send it back.

[arne997]

I think the Gaui RCP blades are 3 deg twisted, all of them. You cant see it but if you take a pitch gauge you see it.
The problem is that 3 deg is much and it is impossible to know the o deg pitch point at mid stick if you dont messure it. I cant feel it when flying. So if the o deg point should be messured on the blade tips or in the middle that is a question?

BR

[mjdee14]

most likely the best to measure would be at center gravity on the blade...which would be around the center of lift.....but a deg here or there shouldn't make a big dif....

If you measure + and - pitch at the same location...and you have 50% set for midstick...it should be close enough for gov't work. If you have the same + and - at max

[bearwood]

most likely the best to measure would be at center gravity on the blade...which would be around the center of lift

I think what you mean is the centre of balance.
The CoG of the blade is rear of the leading edge somewhere near the thickest part of the chord. It is not a measurement along its span.

I personally measure at the blade grip but we are different.

I think that for a fully symetrical blade there should be no twist as this would affect the inverted flight characteristics.
A semi symetrical blade or flat bottom blade could quite possibly have some +ve twist towards the tip to help stabilise the blade in flight. From memory I think this slows down the onset of tip stall.

[bugdozer]

Also, make sure your fly-bar is held parallel with the tail boom while you measure your pitch. Any movement will affect your pitch reading.

I know my RCP's are not warped, 0 degrees the full length.

[mjdee14]

I think what you mean is the centre of balance.
The CoG of the blade is rear of the leading edge somewhere near the thickest part of the chord. It is not a measurement along its span.

I personally measure at the blade grip but we are different.

I think that for a fully symetrical blade there should be no twist as this would affect the inverted flight characteristics.
A semi symetrical blade or flat bottom blade could quite possibly have some +ve twist towards the tip to help stabilise the blade in flight. From memory I think this slows down the onset of tip stall.

yah...I agree what you said...center of balance...:badair: had a brain fart cause that's what I was thinking.....

[xodarap1]

I just check the four pair of RCP 500mm's that I have here and they are not twisted or warped.. have the same pitch from end to end when checked. Is it possible for you to return the blades and get new ones?

[Pinecone]

The "center of balance" will be the chordwise line that passes through the center of gravity.

And it is very common to specify the CoG in reference to one axis only for specific purposes.