RE: Extreme Flight Extra 300, 50cc, 88.5inch Wingspan, Build !!!!!!!  
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RE: Extreme Flight Ex... - 5/9/2008 2:33:08 AM   
pfoot748


 

Posts: 120
Joined: 8/15/2005
From: , OH, USA
Status: offline 		If running a pipe try out a 23b. On my E.F. Yak I've been running a PT 23x8 for over a year now and decided to try the Vess and wish I had switched long ago. The pull out from the Vess is unbelievable w/Da-50 on E.S. pipe and with the b pitch the speed is very close to the 23x8. The PT took a little time to accelerate straight up and the Vess is instantanious. I'm just a little over 17 lbs.

(in reply to yarom)
       Post #: 851

RE: Extreme Flight E... - 5/9/2008 3:24:00 AM   
Richard D Bahmann aka/Wrongway



Posts: 2041
Joined: 1/7/2004
From: Ormond Beach, FL, USA
Status: online
quote:

ORIGINAL: Milton


The 22-A worked great untill engine got broken in, The RPM went up to 7400 so we went to the 23A to get them down to 7200.

If you do not over rev it I think the 22-A is best

Milton


Milton I do like that engine you have there!


It is hard to over rev the 22A. Here it is on mine at 8400 rpm upline. The prop performs great and still pulls like a mule.

http://www.youtube.com/watch?v=Apz895e8ERw

Even the 23A at 7800 rpm pulls great, of course the engine rev limit should be considered. In the chain saw application the G-62 is desinged to go 13,000 rpm but many of the other model airplane engines are around 8-9000.

Here is the 23A at 7800

http://www.youtube.com/watch?v=jps3cDMJnm4&feature=related


My Vess props pull like a tractor and a half and the uplines are quick enough. I guess it's all preference to what feel one gets from a prop.

Pfoot, I don't know why but the pipe likes those Vess props. My 23A gets 7800 but a NX-23x8 would pull it down to 7000. I think the Vess props let the engine unload into the pipe power better...at least on my setup.

Richard

_____________________________

Gonna kick the tire and light up my
Torch...Gone Flying...WrongWay

(in reply to RC Extreme power)
       Post #: 852

RE: Extreme Flight E... - 5/9/2008 12:57:54 PM   
Jake Ruddy



Posts: 3025
Joined: 5/22/2005
From: Bear, DE, USA
Status: offline 		Vess Props all get more static RPMs than almost any other prop out there.. I have seen this many times. They make a lot of thrust for 3D as well. The problem is they are very loud

PT props are junk as far as I am concerned... there was a lot of hype about them in the beginning and I jumped on that band wagon. Xoar had the same hype. In my testing the PT had the worst raw thrust, then Xoar, and of course Vess came out on top.

I find Mejzlik to be a good selection for thrust and noise and am back to them this year.
       Post #: 853

RE: Extreme Flight E... - 5/9/2008 2:23:14 PM   
BaldEagel



Posts: 4218
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: online
quote:

ORIGINAL: Richard D Bahmann aka/Wrongway

Pfoot, I don't know why but the pipe likes those Vess props. My 23A gets 7800 but a NX-23x8 would pull it down to 7000. I think the Vess props let the engine unload into the pipe power better...at least on my setup.

Richard


There is no magic formular to this, if one prop is letting the engine rev higher it is either very much lighter or its a lower pitch, getting a 23" prop over 7500rpm you are getting very close to the retreating blade turbulance interfearing with the thrust produced by the advancing blade and cavitation resulting you may not even notice this in flight, but you will notice an increase in noise as the tip of the blade is very close to Mach 1 in clear air and will go through Mach 1 in turbulant air. Prop you engine for the manufactures recommended max tourque rpm, it will generally be about the 7000rpm figure on a 50cc.

Mike


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No matter what anyone says 100% is the maximum you can get.
       Post #: 854

RE: Extreme Flight E... - 5/9/2008 4:06:55 PM   
Richard D Bahmann aka/Wrongway



Posts: 2041
Joined: 1/7/2004
From: Ormond Beach, FL, USA
Status: online
quote:

ORIGINAL: BaldEagel



There is no magic formular to this, if one prop is letting the engine rev higher it is either very much lighter or its a lower pitch, getting a 23" prop over 7500rpm you are getting very close to the retreating blade turbulance interfearing with the thrust produced by the advancing blade and cavitation resulting you may not even notice this in flight, but you will notice an increase in noise as the tip of the blade is very close to Mach 1 in clear air and will go through Mach 1 in turbulant air. Prop you engine for the manufactures recommended max tourque rpm, it will generally be about the 7000rpm figure on a 50cc.

Mike




Hey Mike,

I would agree with the above with traditional one pitch blades. To me, the Vess props are different. Maybe it is the computer optimization...the pitch is not constant and the sweep is also not constant. They just seem to work better in the upper end of the rpm range. That is just what I see after using it vs others I have used.

The Vess props are noisy at higher rpm's, cant deny that. Either will rip the air hard with a certain throttle setting when on a down line. I don't usually need big power and always can adjust the throttle to avoid that. For pulling vertical or adjusting low and mid range thrust in 3D they grap the air very well.


_____________________________

Gonna kick the tire and light up my
Torch...Gone Flying...WrongWay

(in reply to BaldEagel)
       Post #: 855

RE: Extreme Flight E... - 5/9/2008 4:28:20 PM   
BaldEagel



Posts: 4218
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: online 		Richard

Not trying to start a war, but computer optimised or not, the engine is not producing any more power just by changing the prop, if it increases in rpm it is loaded less no matter what the pitch change accross the blade is.

IMO Vess props are far too noisy for any environment, there are easier ways of getting more power or the power you require, I have a QQ Yak which I fly at sea level, I had an MVVS 45 in it and it flew very well, unlimited verticle and all that, but even with a cannister silencer I considered it too noisy, so I put an MVVS 58 Pro in it, same silencer, too much power so all of the flight is at part throttle, it is now much more acceptable, and much more fun to fly. Due to ground clearance problems with the Yak I am using a three blade Mejzlik 22x10 and restricting the revs to 7000rpm.

Noise is a pollutant.

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.
       Post #: 856

RE: Extreme Flight E... - 5/9/2008 4:51:29 PM   
Richard D Bahmann aka/Wrongway



Posts: 2041
Joined: 1/7/2004
From: Ormond Beach, FL, USA
Status: online 		Mike, remember that we are Allies! No war taken.

Oh did I forget to mention that the piped setup is set to come on at around 7400? So the NX prop loaded it down where it never got up on the pipe where as the Vess unloaded into the pipe which allowed it to exceed with the added power. So in fact the engine was able to achieve more power. (sorry I forgot to mention the pipe)

I know that the days are coming when I can't fly a noisy setup. I can actually do all that I want on this setup and stay in the quiet zone since it will do it all on about 1/2 throttle. On some days I will fly the first 3/4 of a flight at 1/2 throttle or below then pull into a hover and go WOT to punch out. Suddenly everyone is looking at my plane again!! I wonder where max torque is on a G-62? Ralph says that they were designed for a 13,000 rpm chain saw. I should as where best torque is.

For those times I want really quiet, I do have a plane that is wisper quiet with a different setup.

Why do we do 3D throws when 1/4 of that will fly the plane aerobatically. You got it but you use it only when you choose. Same with power.

For those of you guys looking for a really quiet setup Vess may not be right although the 22B I have used is much different in the noise department.

R

_____________________________

Gonna kick the tire and light up my
Torch...Gone Flying...WrongWay

(in reply to BaldEagel)
       Post #: 857

RE: Extreme Flight E... - 5/9/2008 6:06:51 PM   
Jake Ruddy



Posts: 3025
Joined: 5/22/2005
From: Bear, DE, USA
Status: offline
quote:

ORIGINAL: BaldEagel

Richard

Not trying to start a war, but computer optimised or not, the engine is not producing any more power just by changing the prop, if it increases in rpm it is loaded less no matter what the pitch change accross the blade is.

IMO Vess props are far too noisy for any environment, there are easier ways of getting more power or the power you require, I have a QQ Yak which I fly at sea level, I had an MVVS 45 in it and it flew very well, unlimited verticle and all that, but even with a cannister silencer I considered it too noisy, so I put an MVVS 58 Pro in it, same silencer, too much power so all of the flight is at part throttle, it is now much more acceptable, and much more fun to fly. Due to ground clearance problems with the Yak I am using a three blade Mejzlik 22x10 and restricting the revs to 7000rpm.

Noise is a pollutant.

Mike



So you added 1.5 pounds to get it quieter?? That doesnt make much sense at all to me. If it was on a proper canister then the engine should be fairly quiet.. the rest for the most part is prop noise. I would have tried a tuned pipe instead or another canister over adding that much weight to get it quieter.

(in reply to BaldEagel)
       Post #: 858

RE: Extreme Flight E... - 5/9/2008 8:45:56 PM   
Richard D Bahmann aka/Wrongway



Posts: 2041
Joined: 1/7/2004
From: Ormond Beach, FL, USA
Status: online 		Just got mine quiet for and hoping to go to the Nall. I put a PT 24x8 on it and re tuned and got 7100 cold and 6950 hot. The last time I used this prop I was not happy but seem to have better throttle response since fiddling with the low end. It is interesting that if what I have learned about my setup coming on pipe boost at mid 7k range then I have not made it there with this prop. Also with the heavier load the engine wanted more fuel. (high end went from 7/8 of a turn to 1 1/2, low end went out a little too)

I bet I lost 6 lbs of thrust over the 22A but but still will have good vertical, just not on steriods. I was hoping to fly today but the wind is gusting and I may not get out. I am curious on how the performance will be with new tuning.

_____________________________

Gonna kick the tire and light up my
Torch...Gone Flying...WrongWay

(in reply to Jake Ruddy)
       Post #: 859

RE: Extreme Flight E... - 5/10/2008 1:31:02 AM   
diamondave



Posts: 1673
Joined: 9/2/2004
From: marana, AZ, USA
Status: offline
quote:

ORIGINAL: Richard D Bahmann aka/Wrongway

Just got mine quiet for and hoping to go to the Nall. I put a PT 24x8 on it and re tuned and got 7100 cold and 6950 hot. The last time I used this prop I was not happy but seem to have better throttle response since fiddling with the low end. It is interesting that if what I have learned about my setup coming on pipe boost at mid 7k range then I have not made it there with this prop. Also with the heavier load the engine wanted more fuel. (high end went from 7/8 of a turn to 1 1/2, low end went out a little too)

I bet I lost 6 lbs of thrust over the 22A but but still will have good vertical, just not on steriods. I was hoping to fly today but the wind is gusting and I may not get out. I am curious on how the performance will be with new tuning.


pt 24-8 ehhh, wink wink, were did you get that?? haha...inside joke
       Post #: 860

RE: Extreme Flight E... - 5/10/2008 1:37:16 AM   
RC Extreme power



Posts: 968
Joined: 12/30/2001
From: AUBURN, GA, USA
Status: online 		All i know is here are two vedios, One with A carbon Fiber the other with Vess

Same plane, Same motor, same test stand. All that was done was to change the prop.

RPM about the same on all props + - 30 rpm

The Vess put out 3 more pounds of thrust, Not saying engine had more power with the Vess just more pounds of thrust


Posted this vedio earler
Vess 22-A and 23-a
http://www.youtube.com/watch?v=u7hn80t3UQ8



Carbon fiber Mejzlik
http://www.youtube.com/watch?v=oKCfkTZ259E

< Message edited by Milton -- 5/10/2008 1:40:15 AM >

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       Post #: 861

RE: Extreme Flight E... - 5/10/2008 2:04:26 AM   
Jake Ruddy



Posts: 3025
Joined: 5/22/2005
From: Bear, DE, USA
Status: offline 		There is no doubt Vess has more thrust... they win hands down. The problem is they are so loud. Really who needs 29 pounds of thrust on a 15-18 pound plane?

< Message edited by Jake Ruddy -- 5/10/2008 2:08:39 AM >

(in reply to RC Extreme power)
       Post #: 862

RE: Extreme Flight E... - 5/12/2008 5:02:54 PM   
wavy777


 

Posts: 275
Joined: 11/1/2004
From: Oxfordshire, UNITED KINGDOM
Status: offli