20X6 wood for 26cc
05-04-2008, 06:06 AM
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20X6 wood for 26cc
hello guys. I ahve sv266 with cherry 17X8 prop, I hate that combo, cause this damn cheap propeller gives me only 5.4 kg of thrust. anybody has tryed to measure thrust or some rpm figures when spinning 18X6 or 20X6 wood on 26cc engine? I hope I can get about 6-6,5 kg with this engine for my custom built 1,8 m giles 202, which weights 4.3kg
05-04-2008, 09:27 AM
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RE: 20X6 wood for 26cc
We did thrust tests on a CRRC pro 26cc and found that
we could get 14.5 lbs on a Zinger 16x5 prop !!!!!!!!!!!!!
A pleasent surprize needles to say .....
05-04-2008, 09:46 AM
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RE: 20X6 wood for 26cc
The bigger problem is your engine... for a 26 they are low on power. You can try and put on a Mejzlik and you will gain some thrust for sure... but in the end your limiting factor is going to be the engine.
That engine will be lucky to turn a good 18x6 in the low - mid 7000. The high quality 26s on the market will turn that prop around 9000.
That engine will be lucky to turn a good 18x6 in the low - mid 7000. The high quality 26s on the market will turn that prop around 9000.
05-04-2008, 10:05 AM
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RE: 20X6 wood for 26cc
kewl hopefully the tune pipes guys will chime in as that is the word from Dick H in how to get some power out the 30cc or below engines.....
05-04-2008, 11:12 AM
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RE: 20X6 wood for 26cc
ORIGINAL: Walt and Sage
We did thrust tests on a CRRC pro 26cc and found that
we could get 14.5 lbs on a Zinger 16x5 prop !!!!!!!!!!!!!
A pleasent surprize needles to say .....
We did thrust tests on a CRRC pro 26cc and found that
we could get 14.5 lbs on a Zinger 16x5 prop !!!!!!!!!!!!!
A pleasent surprize needles to say .....
so have u measured rpm?
05-04-2008, 11:37 AM
#11
RE: 20X6 wood for 26cc
ORIGINAL: gadix
i thought that zenoah have a warninng limit not to cross the 7600rpms???
i thought that zenoah have a warninng limit not to cross the 7600rpms???
Karol
05-04-2008, 05:24 PM
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RE: 20X6 wood for 26cc
The zenoah comes to life above 8500.
My MVVS test engine ran a 18x10 APC prop on tuned MVVS pipe at 8200 rpm (low thrust!), 18x6 Mejzlik at 9000, and a Menz-S 18x8 at 7600. This prop gave me best thrust of 18.5 lbs static (FWIW). A 20x6 would go supersonic in slightly descending level flight, and was banned at our field because of that. It was no fun prop, because at idle it put the brakes on too hard.
My MVVS test engine ran a 18x10 APC prop on tuned MVVS pipe at 8200 rpm (low thrust!), 18x6 Mejzlik at 9000, and a Menz-S 18x8 at 7600. This prop gave me best thrust of 18.5 lbs static (FWIW). A 20x6 would go supersonic in slightly descending level flight, and was banned at our field because of that. It was no fun prop, because at idle it put the brakes on too hard.
05-04-2008, 09:35 PM
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RE: 20X6 wood for 26cc
CRRC Pro GF26I with CRRC Pro pitts muffler.
Xoar 16 X 8 @ 8400 rpm
SY 16 X 8 @ 8750 rpm
Master Airscrew Classic 16 X 10 @ 7800 rpm
Xoar 17 X 6 @ 8400 rpm
APC 17 X 6 @ 9350 rpm
Xoar 17 X 8 @ 7500 rpm
Master Airscrew wood 18 X 6 @ 7200 rpm
Xoar 18 X 6 @ 7800 rpm
APC 18 X 6W @ 7800 rpm
Xoar 18 X 8 @7400 rpm
Xoar 16 X 8 @ 8400 rpm
SY 16 X 8 @ 8750 rpm
Master Airscrew Classic 16 X 10 @ 7800 rpm
Xoar 17 X 6 @ 8400 rpm
APC 17 X 6 @ 9350 rpm
Xoar 17 X 8 @ 7500 rpm
Master Airscrew wood 18 X 6 @ 7200 rpm
Xoar 18 X 6 @ 7800 rpm
APC 18 X 6W @ 7800 rpm
Xoar 18 X 8 @7400 rpm
05-05-2008, 06:01 AM
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RE: 20X6 wood for 26cc
ORIGINAL: pe reivers
The zenoah comes to life above 8500.
My MVVS test engine ran a 18x10 APC prop on tuned MVVS pipe at 8200 rpm (low thrust!), 18x6 Mejzlik at 9000, and a Menz-S 18x8 at 7600. This prop gave me best thrust of 18.5 lbs static (FWIW). A 20x6 would go supersonic in slightly descending level flight, and was banned at our field because of that. It was no fun prop, because at idle it put the brakes on too hard.
The zenoah comes to life above 8500.
My MVVS test engine ran a 18x10 APC prop on tuned MVVS pipe at 8200 rpm (low thrust!), 18x6 Mejzlik at 9000, and a Menz-S 18x8 at 7600. This prop gave me best thrust of 18.5 lbs static (FWIW). A 20x6 would go supersonic in slightly descending level flight, and was banned at our field because of that. It was no fun prop, because at idle it put the brakes on too hard.
so when it goes supersonic, it just stops revving up (as I know)?
So it's possible to get about 18lb of static thrust from this engine? hmmmm [sm=72_72.gif]
05-05-2008, 06:45 AM
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RE: 20X6 wood for 26cc
ORIGINAL: bako
So it's possible to get about 18lb of static thrust from this engine? hmmmm [sm=72_72.gif]
So it's possible to get about 18lb of static thrust from this engine? hmmmm [sm=72_72.gif]
The best I have personally seen with my 26cc is 14 - 14 1/2lb.
Maybe someone could get more with a header and can, but most 26cc are probally topping out at the 13 - 15 lbs of thrust range.
18lbs of thrust seems to be more of a 36cc to 40cc range to me.
But, if pe reivers is turning a 18x6 Mejzlik at 9000, I guess it is possible for a his 26cc since I can turn a 17 X 6 @ 9350rpm on mine.
A 18x6 Mejzlik at that rpm could be in that thrust range.
05-05-2008, 08:21 AM
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RE: 20X6 wood for 26cc
Several engines are doing an 18x6 Mejzlik right around 9000 on a stock muffler. The G-26 and Brillelli 26 will both do it. My B26 was dong an APC 18x6W at 8750 on 2nd tank of fuel with a stock muffler.
05-05-2008, 08:54 AM
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RE: 20X6 wood for 26cc
ORIGINAL: bako
so have u measured rpm?
ORIGINAL: Walt and Sage
We did thrust tests on a CRRC pro 26cc and found that
we could get 14.5 lbs on a Zinger 16x5 prop !!!!!!!!!!!!!
A pleasent surprize needles to say .....
We did thrust tests on a CRRC pro 26cc and found that
we could get 14.5 lbs on a Zinger 16x5 prop !!!!!!!!!!!!!
A pleasent surprize needles to say .....
so have u measured rpm?
YES we did..
16x5 Zinger was 9030...
Any smaller and it over revs..
Any larger EVEN 16x6 and the lbs of thust drops
to 11 and under WILL ALL LARGER PROPS>>
We wanted lbs of thrust to hover and pull out FAST
for an 10.2 lbs plane
Walt..
[/color]
05-05-2008, 07:08 PM
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RE: 20X6 wood for 26cc
Sorry guys, I don't know what the heck I was reading , but I thought Walt and Sage said he was getting 18 lbs. of thrust from his 26cc.
That why I was sceptical and was saying those numbers seem mor of the 40cc class.
My Bad.
So it's a Zinger 16 X 5 @ about 9000 - 9100 rpm with 14 1/2 lbs of thrust, Right?
That why I was sceptical and was saying those numbers seem mor of the 40cc class.
My Bad.
So it's a Zinger 16 X 5 @ about 9000 - 9100 rpm with 14 1/2 lbs of thrust, Right?
05-05-2008, 07:18 PM
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RE: 20X6 wood for 26cc
Should really try a small Vess if thrust is what you want... the name Zinger and thrust generally dont belong in the same sentance.
2robin.. it was pe saying 18 pounds thrust with an 18x6 at 9k.
2robin.. it was pe saying 18 pounds thrust with an 18x6 at 9k.
05-06-2008, 12:21 AM
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RE: 20X6 wood for 26cc
There must be a differance in static thrust and the actual pull on a scale, right?
This thrust calculator ( linked below ) show that an APC 17 X 6 that I am turning @ 9450 rpm has a static thrust of 22.37 lbs.
On the digital scale, I am getting an actual pull of 13 lbs. 13 oz. @ 9450 rpm.
Thats almost 9 lbs. differance 9 ( ?????????? )
This must be where pe reivers got his numbers from, it show the Menz-S 18 X 8 @ 7600rpm is 17.67 lbs. of static thrust.
I turned a Xoar 18 X 8 @ 7400 rpm and it pulled an actual 11.0 lbs. on the scale.
The Menz-S and Xoar maybe close and that makes it about 5 -6 lbs. differance in actual pull power.
Am I doing this right?
http://www.lcrcc.net/thrust_calc.htm
This thrust calculator ( linked below ) show that an APC 17 X 6 that I am turning @ 9450 rpm has a static thrust of 22.37 lbs.
On the digital scale, I am getting an actual pull of 13 lbs. 13 oz. @ 9450 rpm.
Thats almost 9 lbs. differance 9 ( ?????????? )
This must be where pe reivers got his numbers from, it show the Menz-S 18 X 8 @ 7600rpm is 17.67 lbs. of static thrust.
I turned a Xoar 18 X 8 @ 7400 rpm and it pulled an actual 11.0 lbs. on the scale.
The Menz-S and Xoar maybe close and that makes it about 5 -6 lbs. differance in actual pull power.
Am I doing this right?
http://www.lcrcc.net/thrust_calc.htm
05-06-2008, 12:55 AM
#22
RE: 20X6 wood for 26cc
ORIGINAL: 2robinhood
There must be a differance in static thrust and the actual pull on a scale, right?
This thrust calculator ( linked below ) show that an APC 17 X 6 that I am turning @ 9450 rpm has a static thrust of 22.37 lbs.
On the digital scale, I am getting an actual pull of 13 lbs. 13 oz. @ 9450 rpm.
Thats almost 9 lbs. differance 9 ( ?????????? )
This must be where pe reivers got his numbers from, it show the Menz-S 18 X 8 @ 7600rpm is 17.67 lbs. of static thrust.
I turned a Xoar 18 X 8 @ 7400 rpm and it pulled an actual 11.0 lbs. on the scale.
The Menz-S and Xoar maybe close and that makes it about 5 -6 lbs. differance in actual pull power.
Am I doing this right?
http://www.lcrcc.net/thrust_calc.htm
There must be a differance in static thrust and the actual pull on a scale, right?
This thrust calculator ( linked below ) show that an APC 17 X 6 that I am turning @ 9450 rpm has a static thrust of 22.37 lbs.
On the digital scale, I am getting an actual pull of 13 lbs. 13 oz. @ 9450 rpm.
Thats almost 9 lbs. differance 9 ( ?????????? )
This must be where pe reivers got his numbers from, it show the Menz-S 18 X 8 @ 7600rpm is 17.67 lbs. of static thrust.
I turned a Xoar 18 X 8 @ 7400 rpm and it pulled an actual 11.0 lbs. on the scale.
The Menz-S and Xoar maybe close and that makes it about 5 -6 lbs. differance in actual pull power.
Am I doing this right?
http://www.lcrcc.net/thrust_calc.htm
Mark
05-06-2008, 01:19 AM
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RE: 20X6 wood for 26cc
mmattockx mentioned right!!! there is big difference what fuse you have. is it slim one, or it's fat, what shapes does it have. so one staff is static thrust and another is total thrust of the airplane. (pull power)
for instance: will u have the same pull power with same engine prop combo o the geebee and for example on stringer? of course not.
so please, don't mess this things. and instead of this fact Ithink that the simple thrustHP calculator is working with not a catastrofic misses with reality.
for instance: will u have the same pull power with same engine prop combo o the geebee and for example on stringer? of course not.
so please, don't mess this things. and instead of this fact Ithink that the simple thrustHP calculator is working with not a catastrofic misses with reality.
05-06-2008, 01:52 AM
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RE: 20X6 wood for 26cc
ORIGINAL: mmattockx
Pe got his numbers by actual testing. LOTS of testing. He also developed the only prop / power calculator worth having. Go to his site (in his sig) and look for the downloads. His calculator works because he has done a ton of testing to get accurate prop load factors. BTW, Pe's calculator says your APC 17x6 @ 9450rpm = 17.6lb static thrust with a free prop and 16.2lbs with fuselage interference at sea level. At 2500ft, it gives 16.7lb free and 15.3lb with fuse interference.
Mark
Pe got his numbers by actual testing. LOTS of testing. He also developed the only prop / power calculator worth having. Go to his site (in his sig) and look for the downloads. His calculator works because he has done a ton of testing to get accurate prop load factors. BTW, Pe's calculator says your APC 17x6 @ 9450rpm = 17.6lb static thrust with a free prop and 16.2lbs with fuselage interference at sea level. At 2500ft, it gives 16.7lb free and 15.3lb with fuse interference.
Mark