Carolina BarnStormers Spring 2021

ultracruiser41

Gold Member
Joined
Nov 2, 2003
Messages
2,855
Location
NC
Aircraft
Cavalon, OutBack Tango, Ryan PT 22, JetGyro, Jet Provost, Champ, Radial Rocket Gyro, HummelBird
Total Flight Time
Too many to count

Boots

Active Member
Joined
May 1, 2010
Messages
1,062
Location
Mooresville NC.
Aircraft
GYROBEE 447 / Sport Copter
Yes I do know the owner .
He is a well known builder and I would assume his Prop is balanced .
 

wolfy

Gold Supporter
Joined
Dec 19, 2013
Messages
791
Location
western australia
Yes I do know the owner .
He is a well known builder and I would assume his Prop is balanced .
Thanks mate, I would also imagine his prop is balanced but I was wondering about the two per rev pulses.
Seems to be the culprit for a two blade being less smooth than 3+ blade props.

wolfy
 

ultracruiser41

Gold Member
Joined
Nov 2, 2003
Messages
2,855
Location
NC
Aircraft
Cavalon, OutBack Tango, Ryan PT 22, JetGyro, Jet Provost, Champ, Radial Rocket Gyro, HummelBird
Total Flight Time
Too many to count
Thanks mate, I would also imagine his prop is balanced but I was wondering about the two per rev pulses.
Seems to be the culprit for a two blade being less smooth than 3+ blade props.

wolfy
The reason why most gyros go to a 3 blade prop is due to limited space for longer props. The less blades.....the more efficient the prop. Multiple blades means each blade is traveling through the prop wash (disrupted air) of the previous blade.
Some gliders use a single blade prop with a counter balance.....very efficient prop.
 

JETLAG03

Active Member
Joined
Jul 6, 2019
Messages
321
Location
france
Total Flight Time
300+ flexwing (pendulaire) newly trained on gyrocopter ((autogire)11h)
@ultracruiser41 if one has less blades (on a prop) does the blade cord need to be bigger ie cord on a 2 blade 50% bigger than a 3 blade ?

phil
 

ultracruiser41

Gold Member
Joined
Nov 2, 2003
Messages
2,855
Location
NC
Aircraft
Cavalon, OutBack Tango, Ryan PT 22, JetGyro, Jet Provost, Champ, Radial Rocket Gyro, HummelBird
Total Flight Time
Too many to count
@ultracruiser41 if one has less blades (on a prop) does the blade cord need to be bigger ie cord on a 2 blade 50% bigger than a 3 blade ?

phil
Not that I'm aware of....due to the blade being more efficient.....but I'll leave that to the experts we have here on the forum.
 

NetPilot

Tryin' to Re-Member
Joined
Oct 12, 2008
Messages
668
Location
Atlanta, GA
Aircraft
2016 Rotax 503 "Jake-inator" (i.e. Gyro Jake's 2016 creation)
Total Flight Time
300+
By the way, that second picture 'flock-of-gyros' looks photoshopped... but being the one in the top right with the orange shirt, I can vouch for the fact that it is very real... and fun as heck!

The folks who didn't make it to this one missed a heck of a fly-in!!

M
 

wolfy

Gold Supporter
Joined
Dec 19, 2013
Messages
791
Location
western australia
The reason why most gyros go to a 3 blade prop is due to limited space for longer props. The less blades.....the more efficient the prop. Multiple blades means each blade is traveling through the prop wash (disrupted air) of the previous blade.
Some gliders use a single blade prop with a counter balance.....very efficient prop.
Yep agreed.
Less blades more efficient, more blades usually considered smoother.
My reason for asking was only about smoothness as I am going to try a two blade to be more efficient.

wolfy
 

JETLAG03

Active Member
Joined
Jul 6, 2019
Messages
321
Location
france
Total Flight Time
300+ flexwing (pendulaire) newly trained on gyrocopter ((autogire)11h)
Yep agreed.
Less blades more efficient, more blades usually considered smoother.
My reason for asking was only about smoothness as I am going to try a two blade to be more efficient.

wolfy
Go on, give the mono blade a go. It looks rather unusual. o_O
 

gyrojake

Gyro Rehab Candidate
Joined
Jan 1, 2007
Messages
2,284
Location
E-City, Florida
Aircraft
Gyroplanes
Total Flight Time
A few hours
By the way, that second picture 'flock-of-gyros' looks photoshopped... but being the one in the top right with the orange shirt, I can vouch for the fact that it is very real... and fun as heck!

The folks who didn't make it to this one missed a heck of a fly-in!!

M
Best lookin gyro there :) :)
 
Joined
Sep 9, 2019
Messages
8
Location
Marion, VA
I made it and had a great time as well! Thanks for all the help and support in getting my gyro back together! See you in the fall!
 

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N962GT

Newbie
Joined
Oct 25, 2020
Messages
36
Location
Northville, Michigan
Aircraft
Mohawk Arrow 140T
Total Flight Time
800 hrs
The reason why most gyros go to a 3 blade prop is due to limited space for longer props. The less blades.....the more efficient the prop. Multiple blades means each blade is traveling through the prop wash (disrupted air) of the previous blade.
Some gliders use a single blade prop with a counter balance.....very efficient prop.
On the flip side, more blades = less burden per blade. In order to go with only two blades with this much HP you'd think you kinda need something wide and beefy, like a Whirlwind flat bottom airboat prop or the enormous wooden spoons on the Twinstar gyros seen at Mentone every year.

I've sold a bunch of Mohawk Yamaha Genesis 4-cylinder (YG4) 150HP 165 lb kits to airboat guys in Louisiana, Canada and Alaska. Some use Whirlwind airboat two-blade props like this, others go with Warp Drive 3-blade. They all seem to be happy, getting 4 GPH/hr. at far less weight and a fraction of the cost with no difference in reliability or endurance - which goes for cross-country aircraft happily criss-crossing the continent for the last 7 years as well as airboats running all day long.

I don't have any feedback from anyone who has compared a 2-blade Whirlwind airboat prop to a 3-blade Warp, NR/Luga, Aero, Prince, or Whirlwind. I do know from lots of customer feedback over the years that all these 3-blade props outperform their four blade counterparts, but in testing on a 195 HP NOS-boosted (w/ Mohawk PSRU adapter, ahem) YG4 on the champion "Yee-Haw" Highlander STOL plane of Steve Henry that walked away from Oshkosh 2018 with every race win and the top Airventure Lindy LSA award, the two-blade props he tested on that platform came nowhere near the flight performance realized with the three-blade NR scimitar prop, despite any reduced drag from running fewer blades.

I know, go figure, right? Both the Lycoming O-320 and the YG4 produce similar power spinning their props at similar speeds. One is hard-coupled to the crankshaft (Lyco) and burns 8 GPH weighing 280 lbs, the other (YG4) has a harmonic damper between the crank and the prop, weighs 165 lbs and burns 4 GPH. I would think that either power plant could run either prop, with similar results comparing one engine to the other.

In the end perhaps it just looks cool. Which is good enough for me!

But I don't think I've ever seen a Lyco running a thin profile, 3-blade Warp, NR, etc. Thangs that make ya go, "Hmmm."
 

13brv3

Gold Member
Joined
Nov 27, 2003
Messages
647
Location
Tellico Plains, TN
But I don't think I've ever seen a Lyco running a thin profile, 3-blade Warp, NR, etc. Thangs that make ya go, "Hmmm."

The 4 cyl direct drive aircraft engines have huge cylinders, and produce large power pulses. In one revolution of the prop, there are only 2 power pulses, compared to many smaller pulses for a geared engine. Props take a lot more abuse for the low RPM direct drive LyConts.

Rusty
 

ultracruiser41

Gold Member
Joined
Nov 2, 2003
Messages
2,855
Location
NC
Aircraft
Cavalon, OutBack Tango, Ryan PT 22, JetGyro, Jet Provost, Champ, Radial Rocket Gyro, HummelBird
Total Flight Time
Too many to count
The 4 cyl direct drive aircraft engines have huge cylinders, and produce large power pulses. In one revolution of the prop, there are only 2 power pulses, compared to many smaller pulses for a geared engine. Props take a lot more abuse for the low RPM direct drive LyConts.

Rusty
I dunno.......most every aircraft I’ve own or flown has a Lycoming with 2 blade props.....pretty standard and must work well.......been doing it for many, many years.
 
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