Leaving aside other arguments for or against the 2 vs 3 blade prop choice, can anyone who has flown behind both the Catto 2 blade and 3 blade give an opinion on the difference in smoothness? I've had people tell me the 2 blade is nice and smooth compared to a metal prop, and I've heard that the 3 blade Catto is smooth compared to the 2 blade Catto. Is it truly a noticeable difference?
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Catto 2 vs 3 Blade - Smoothness
- Thread starter skelrad
- Start date
YES!!!!!!!!!!!!!!!!!
Ed_Wischmeyer
Well Known Member
What about ease of taking the cowling on and off, 2 vs 3 blade?
Yep, I know the 3 blade comes with a little more difficulty in removing the cowl. That's no biggie. I'm mostly interested in how it feels to run vs the 2 blade. It sounds like it truly is smoother.
ShannonEvans
Active Member
Catto 2 vs 3
Can't speak to the 2 vs 3 blade issue, but I loved my 2 blade on my RV-3. Thought the 3 blade would look cool but Craig Catto talked me out of it and said I would really gain nothing. Had to take his word for it. Great prop either way.
Can't speak to the 2 vs 3 blade issue, but I loved my 2 blade on my RV-3. Thought the 3 blade would look cool but Craig Catto talked me out of it and said I would really gain nothing. Had to take his word for it. Great prop either way.
GalinHdz
Well Known Member
I was told by an Aero Engineer friend that it was due to the engine and propeller combination. With a 4 cylinder engine a 2B propeller will always be at the same location when each cylinder is in its power stroke. 2 is a simple multiple of 4. But a 3B prop will be at different locations when each cylinder is in its power stroke. 3 is not a simple multiple of 4 and that is why it creates "less" overall vibrations.
He also said that with a 6cy engine it really doesn't matter if the prop is 2 or 3 blades since 2 and 3 are both simple multiples of 6.
FWIW: I took his word for it and went from a Sensenich 2B to a CATTO 3B on my O-360. I noticed a difference, but that could have been due to the manufacturer.
He also said that with a 6cy engine it really doesn't matter if the prop is 2 or 3 blades since 2 and 3 are both simple multiples of 6.
FWIW: I took his word for it and went from a Sensenich 2B to a CATTO 3B on my O-360. I noticed a difference, but that could have been due to the manufacturer.
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This is true. A 4 cylinder engine fires twice per revolution. Blades always in same position at firing.
db1yg
Well Known Member
2 vs 3
Howdy Brandon,
I had the opportunity to test fly a 2 blade Catto and a 3 blade Catto back to back on the same airplane.
Back in 2014-2017 I tested propellors for Craig on side by side RV aircraft--used my IO360 powered RV9a as the test bed. Lost count as to the number of props on that plane but on one occasion, out of my own curiosity, I tested my personal 3rd gen 3 blade 74.5 inch pitch Catto against a buddy's 3rd gen 2 blade 74.5 inch pitch Catto. Got some base line info on day 1 with the 3 blade then switched to the 2 blade in the afternoon and tested it on the same card as the 3 blade on day 2.
The 3 blade was smoother and noticeably quieter as well given the shorter blades and slower prop tip speeds. I used a phone app to check aircraft vibration in flight to confirm the difference in perceived smoothness.
Ref performance, as expected the 3 blade got off the runway quicker, climbed slightly better, but was 1.5 to 2 knots slower in cruise.
I would have to say both props were smooth but the nod went to the 3 blade.
Craig has since gone to newer generational designs and I do not know if my results still hold but I would say you really can't go wrong with a Catto Propellor--and they are so **** pretty!!!
Hope this helps,
Cheers,
db
Howdy Brandon,
I had the opportunity to test fly a 2 blade Catto and a 3 blade Catto back to back on the same airplane.
Back in 2014-2017 I tested propellors for Craig on side by side RV aircraft--used my IO360 powered RV9a as the test bed. Lost count as to the number of props on that plane but on one occasion, out of my own curiosity, I tested my personal 3rd gen 3 blade 74.5 inch pitch Catto against a buddy's 3rd gen 2 blade 74.5 inch pitch Catto. Got some base line info on day 1 with the 3 blade then switched to the 2 blade in the afternoon and tested it on the same card as the 3 blade on day 2.
The 3 blade was smoother and noticeably quieter as well given the shorter blades and slower prop tip speeds. I used a phone app to check aircraft vibration in flight to confirm the difference in perceived smoothness.
Ref performance, as expected the 3 blade got off the runway quicker, climbed slightly better, but was 1.5 to 2 knots slower in cruise.
I would have to say both props were smooth but the nod went to the 3 blade.
Craig has since gone to newer generational designs and I do not know if my results still hold but I would say you really can't go wrong with a Catto Propellor--and they are so **** pretty!!!
Hope this helps,
Cheers,
db
PilotjohnS
Well Known Member
My. 3 blade Catto
I think the 3 vs 2 debate can be settled by saying to me smoothness is not most important. I think a prop dynamically balanced would be best, 3 or 2 blade.
I chose the 3 blade because Catto said cruising up high, the 3 blade would preform slightly better. Also, there is an inherent benefit with a 3 blade and its moment of inertia not varying through one revolution when there is a axis offset to the direction of flight. Why do you think Hughes helicopters used 3 blades for their Hughes 300C, they knew something Bell did not?
I think the 3 vs 2 debate can be settled by saying to me smoothness is not most important. I think a prop dynamically balanced would be best, 3 or 2 blade.
I chose the 3 blade because Catto said cruising up high, the 3 blade would preform slightly better. Also, there is an inherent benefit with a 3 blade and its moment of inertia not varying through one revolution when there is a axis offset to the direction of flight. Why do you think Hughes helicopters used 3 blades for their Hughes 300C, they knew something Bell did not?
YEP; I was an early adopter of Craig's props on my RV-6. 3-Blade, fiberglas, December of 2003. I think I sold a few for him.
2-blade vs 3- blade
I have been flying with a Catto 3-blade on my RV 9A for the last 2 years and recently tested a Catto 2-blade on the same plane (Titan IO-370, 185 HP). Both props are 68 inches diameter, but different pitches (3-blade 71 in, 2-blade 78 in). Both props were dynamically balance to 0.06 IPS or less. The 3-blade is noticeably smoother at the same RPM. I would suspect that the newer 3-blade prop model with a diameter of 66 inches is even better.
Because the prop pitches are different, it's not a direct comparison. Also, the 2-blade Catto is smoother than 2-blade Sensenich props that I have flown behind. The cowl issue wouldn't be a deciding factor for me, both are a pain. My choice would be a 3-blade prop.
I have been flying with a Catto 3-blade on my RV 9A for the last 2 years and recently tested a Catto 2-blade on the same plane (Titan IO-370, 185 HP). Both props are 68 inches diameter, but different pitches (3-blade 71 in, 2-blade 78 in). Both props were dynamically balance to 0.06 IPS or less. The 3-blade is noticeably smoother at the same RPM. I would suspect that the newer 3-blade prop model with a diameter of 66 inches is even better.
Because the prop pitches are different, it's not a direct comparison. Also, the 2-blade Catto is smoother than 2-blade Sensenich props that I have flown behind. The cowl issue wouldn't be a deciding factor for me, both are a pain. My choice would be a 3-blade prop.
