Making propellers

jinhusong
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Re: Making propellers

Post by jinhusong »

Hi,

We bought 5/32" polystyrene tubing (Evergreen #225) and playing with 0.020" musical wire.

How to make the perfect hole on the tube, and what is the perfect hole? We tried directly use the musical wire, a needle.

Maybe tight is OK? There is no relative movement between the axis and the propeller during flying.

Another question, how the axis will transfer the torque to the propeller? Currently we just bend the wire like a hook (another bend after the 90 degree bend. It works but want to know how the professionals are doing it.

Do we need to do a freewheel on it?

Thanks in advance for your help,

Jinhu
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Re: Making propellers

Post by jander14indoor »

You have it on transferring torque. For this kind of indoor flying you don't need, or even want freewheeling. Ideal indoor flight will be powered throughout the whole time aloft.

Free wheeling is only used for outdoor flight where the idea is to maximize altitude to catch lift.

Jeff Anderson
Livonia, MI
jinhusong
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Re: Making propellers

Post by jinhusong »

jander14indoor wrote:You have it on transferring torque. For this kind of indoor flying you don't need, or even want freewheeling. Ideal indoor flight will be powered throughout the whole time aloft.

Free wheeling is only used for outdoor flight where the idea is to maximize altitude to catch lift.

Jeff Anderson
Livonia, MI
Hi Jeff, Thanks.

We will try to use the blades from Ikara and put them into the tube to play with pitch, just like Dave did.

When we have time, we want to make our own propeller with larger size.

Best,

Jinhu
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Re: Making propellers

Post by klastyioer »

im researching this too cause im new to making wood props
but start on page 94
the page jeff provided is helpful as well (page 4 wright stuff c)
but 94 is easier to comprehend for begs.

https://indoornewsandviews.files.wordpr ... f-inav.pdf
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NigerianScammer
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Re: Making propellers

Post by NigerianScammer »

But wouldn’t wood not be very good for flare propellers because it won’t be able to change pitch?
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Re: Making propellers

Post by CrayolaCrayon »

NigerianScammer wrote:But wouldn’t wood not be very good for flare propellers because it won’t be able to change pitch?
Why can't you change the pitch on a wood prop? If you make the hub right, sure you can.
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Re: Making propellers

Post by klastyioer »

CrayolaCrayon wrote:
NigerianScammer wrote:But wouldn’t wood not be very good for flare propellers because it won’t be able to change pitch?
Why can't you change the pitch on a wood prop? If you make the hub right, sure you can.
by hub do u mean tissue tube that is the like connector for the spars and the link to the hook?
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Re: Making propellers

Post by NigerianScammer »

CrayolaCrayon wrote:
NigerianScammer wrote:But wouldn’t wood not be very good for flare propellers because it won’t be able to change pitch?
Why can't you change the pitch on a wood prop? If you make the hub right, sure you can.
I mean in flight. The idea of the flare prop is that it changes pitch mid flight, but with a wooden prop it won’t have that tendency
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Re: Making propellers

Post by coachchuckaahs »

NigerianScammer wrote:
CrayolaCrayon wrote:
NigerianScammer wrote:But wouldn’t wood not be very good for flare propellers because it won’t be able to change pitch?
Why can't you change the pitch on a wood prop? If you make the hub right, sure you can.
I mean in flight. The idea of the flare prop is that it changes pitch mid flight, but with a wooden prop it won’t have that tendency
The Ikara props flex primarily in the blade. Many built props, such as the Gowen hub, torsionally flex in the spar material. Some may flex in both. Yes, sand balsa thin enough it will flex (but also can be more fragile). Look at the flaps on the ELG gliders.

The flaring prop brings a number of new variables into the mix. You will want to take accurate data on the entire flight (altitude on each circle) in order to fully appreciate what a change in a variable (such as torsional stiffness) does. You may also find that the shape of the blade not only affects the aero of the prop, but also the effective stiffness.

We have been working with flaring props for 4 years now, primarily because our State event has been in a 19' ceiling. Our log book has about 16 columns, plus a notes section, and more than a few columns are related to the design, measurements, and performance of the prop. Good data is critical to understanding and moving forward.

Know that as the prop flexes, the pitch increases. Depending on your stiffness, you may need to have a lower static pitch than previously used on a non-flaring prop, and the pitch will go up in flight.

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Re: Making propellers

Post by klastyioer »

which wood size should i use like which one is most ideal for a ff kit like plane
im currently just experimenting with 1/32 but i have yet to actually test it in flight
i was wondering if i should step up to 1/16 and sand lightly but i dunno
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