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Prop Rip

Old 03-16-2004, 09:08 AM
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RickP
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Default Prop Rip

Hello all,
I have been practicing my sequences and noticed that I am having a hard time preventing "prop rip" Airplane is a 2.6m with a DA-100 and a Mejlik 28-10. I am going to try flattening my throttle curve near the top a little to see if that will help, but can I do something else? How about a different prop? any suggestions to make it easier?
RickP
Old 03-16-2004, 08:49 PM
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Flyfalcons
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Default RE: Prop Rip

Less power on the horizontal line is the key; just use less power. Try to get used to flying at a slower pace for sequence flying. I am flying horizontal lines at 1/3 - 1/2 power, which doesn't seem to rip my 28-10 Mejzlik. If that fails you can get a 25-12 three blade but that's a pricey fix.
Old 03-16-2004, 08:55 PM
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Default RE: Prop Rip

iS "pROP rIP" A STRUCTURAL FAILURE OF THE PROPELLOR? (Rats... darn caps lock)

If it is the root of the prop that is failing, just laminate a couple more plies of carbon around it...

ciao
Old 03-16-2004, 09:44 PM
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Blow n Go
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Default RE: Prop Rip

Rick,

Ryan has it right on. The rip is caused by excessive tip speed. Anything you can do to reduce the prop tip speed will reduce the noise.

CJ
Old 03-16-2004, 10:41 PM
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Forgues Research
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Default RE: Prop Rip

ORIGINAL: RickP

Hello all,
I have been practicing my sequences and noticed that I am having a hard time preventing "prop rip" Airplane is a 2.6m with a DA-100 and a Mejlik 28-10. I am going to try flattening my throttle curve near the top a little to see if that will help, but can I do something else? How about a different prop? any suggestions to make it easier?
RickP
Ripping the prop is so cool, Don't anyone write me, I know its loud, but its so cool anyway[8D]
Old 03-17-2004, 06:03 AM
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Default RE: Prop Rip

Then RIP away!
Old 03-17-2004, 08:19 AM
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RickP
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Default RE: Prop Rip

[quote]ORIGINAL: aerografixs

Ripping the prop is so cool
I hear that brother - but it's not cool loosing 5 points off of every sequence. I took a look at my throttle curve last night and put some more 'umph into 1/2 throttle. Turns out my last two points were at 57% and 75% No wonder - it worked when the motor was new, but now it is more of a switch. Hopefully that's fixed now and I'll try it this weekend.

Giestware,
I'll do a full throttle low level pass just for you to confirm that I can still "Rip" it LOL.
RickP
Old 03-17-2004, 11:58 AM
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Default RE: Prop Rip

OH... "PROP RIP" is the buzzing sound that the prop makes occasionally?!?!?!... I think it sounds cool too... but I fly on a dry lake with NO noise concerns... http://www.radiocontrolzone.com/foru...hreadid=157719

The solution I expect is to reduce the local (resultant) mach number at the tips.... lower rpms or smaller diameter.... or this..... (See Picture)
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Old 03-17-2004, 02:42 PM
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Default RE: Prop Rip

Prop rip-
I see guys overloading engines with props way too big for best performance -to eliminate prop rip-
bad idea .
Some see these big props as bragging rights

Any engine will rip a prop once the plane catches up with and passes the speed where the tips are loaded.
We found out long ago that tho a MenzS 27x10 ripped easily on our 80's, the performance was inferior to a good 26x10 ---
So we just went to better throttle management -
Old 03-17-2004, 10:50 PM
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Default RE: Prop Rip

Yeah, but the neatest sounding rip is that one you get when the plane travels backwards at high rate and starts eating its own wash. It's not loud, but sure sounds cool!
Old 03-18-2004, 08:46 AM
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Default RE: Prop Rip

Prop rip-
I see guys overloading engines with props way too big for best performance -to eliminate prop rip-
bad idea .
Some see these big props as bragging rights
Dick,
That is what I wanted to know - Thanks I'll stay with the 28-10 and put in some throttle curve to help me manage it.

BTW,
Other then the noise is the prop rip damaging in any way to the propeller or airframe? Are there any other side effects... While we are on the subject.
RickP
Old 03-18-2004, 09:46 AM
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rmh
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Default RE: Prop Rip

Good idea.
BTW- the 28x10 Mejzlic is about the same static load as their 27x10 .
Strange - but that's how it seems to be .
So you have POSSIBLY , a higher tip speed with that prop in the air which makes more noise.
We went through a similar test - and found that the Mejzlic 26x10 actually gave better overall performance.
You must exercize more throttle management but the model -in our tests- actually performed better on the smaller prop.
Faster recovery on uplines .
Don't be afraid that the 26x10 is too small for the 100- just use the power needed - then throttle back for the rest of the stuff.
Actually this is much easier on th engine -as it keeps temperatures down.
If you are into the hover stuff - it will also reduce load /heat -which kills lots of engines.
Old 03-19-2004, 08:34 AM
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Default RE: Prop Rip

Okay,
I'll check the SA list and see if I can get some used props to try...
RickP
Old 03-22-2004, 11:34 AM
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Default RE: Prop Rip

I like the way the prop rip sounds when landing on a crosswind the the prop hits the centipede or bermuda..
Old 03-22-2004, 12:27 PM
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Default RE: Prop Rip

ORIGINAL: jongurley

I like the way the prop rip sounds when landing on a crosswind the the prop hits the centipede or bermuda..
If your prop rips when your landing, chances are you will over shoot the runway

Roger
Old 03-22-2004, 12:28 PM
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Default RE: Prop Rip

ORIGINAL: jongurley

I like the way the prop rip sounds when landing on a crosswind the the prop hits the centipede or bermuda..
If your prop rips when landing, chances are that you will overshoot the runway.
Old 03-22-2004, 02:16 PM
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Default RE: Prop Rip

I prop ripped several when they make contact on the ground
Old 03-22-2004, 02:41 PM
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Default RE: Prop Rip

ORIGINAL: jongurley

I prop ripped several when they make contact on the ground
Old 03-23-2004, 12:01 AM
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Default RE: Prop Rip

can my funtana with saito 91 and master airscrew 14x6 make a prop rip?
Old 03-23-2004, 08:36 AM
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Default RE: Prop Rip

ORIGINAL: Funtana_Cody

can my funtana with saito 91 and master airscrew 14x6 make a prop rip?
[X(]
Doubtfull, trade up to a large gasser and there's no going back [8D]
RickP
Old 03-24-2004, 08:55 AM
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Default RE: Prop Rip

Prop Rip on landing has a whole 'nother meaning on a PetroMat runway. Sounds awful.
Old 03-25-2004, 03:08 PM
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Default RE: Prop Rip

Back when I started flying about 5 years ago at age 18, APC was sending recruits to my high school with sponsorship offers I broke my share of props to start with..[8D]

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