Catto Vs Borer floatplane
- Thread starter Revr
- Start date
roxiedog13
Registered User
I suggest calling Catto like I did . I listened to the BS too long so I did something about it. Fanboys don't want to know the truth , they just want to go on believing Catto is outperforming the others with lesser pitch through some superior process.
Nothing superior or magic , the prop increases pitch towards the root , not a constant pitch distribution as with other propeller manufacturers, in particular the Borer which it is being compared to. This is why I say Borer is "honest" whereas
Catto is not.
Whether or not it outperforms any other is irrelevant what is important is knowing which prop to consider if replacing an existing. IF some poor chap were to choose a Catto 82 44 to replace a 82 44 Borer he might very well not be able to spin the prop appropriately for application. He would need a Catto 82 4o or 42 to match the same , would have wasted time and money .
Many apparently just want to contiune in the delusion Catto are doing the same with a 38inch pitch as others do with a 44inch . Catto is not doing as others, apparently they have their own method , you can call that what you want, honest it is not .
But hey, if you are too afraid to call them for yourself, carry on as you have , I expect you will.
roxiedog13
Registered User
Many have said the nickle leading edge helps out very well, better than aluminum in fact. I had a T-craft for 10 years, used both a Sensenich metal and Warp Drive with Nickle leading edge equally over that period. The Warp Nickle did not show any signs of wear, the Sensenich had a number of nicks that had to be cleaned up .
hotrod180
FRIEND
Port Townsend, WA
Yup, no insult or attack going on there.
hotrod180
FRIEND
Port Townsend, WA
Earlier post (#99) from this thread.
I guess Mac is being dishonest and cheating on themselves,
by using different stations to specify angles for different model props.
Those bastards!
roxiedog13
Registered User
I was kind of tired of being called Bitchin or accused of having my undies in a knot, the unarmed witted man and numerous other insults. I should have vacated something sooner to be honest . When someone can only hurl insults , and is too afraid to listen to logic or have a civil conversation , even make that simple phone call .
Like I said it's been insults and BS for a while . I get this is more the Catto is superior thread than, let's actually compare, didn't realize I was walking into the sermon , trying to preach to the congregation as it were .
But hey, I fly the spam can draggy 172 , what would I know , right?
roxiedog13
Registered User
I wonder do you have a catto too ?
Mac do have different angles for pitch distribution BUT because the prop twists , the camber and chord changes they are required to use slightly different angles at each station . End result each station is effectively the same pitch along the blade . This is what a prop shop told me, been in the business 50 years now. Could know a thing or two.
BC12D-4-85
SPONSOR
Fairbanks, AK.
It's angle of attack versus chord line like a wing that creates lift, or thrust for props.
For those that like to read:
http://www.epi-eng.com/propeller_technology/selecting_a_propeller.htm
For those that like sound and pictures:
https://www.youtube.com/watch?v=uzhPkrx_q2U
Numbers may have meaning but comparing these two props via their manufacturer's stated diameter and pitch isn't straightforward. In the end it's engine power vs observed static rpm, rate of climb, and cruise airspeed that matters to the pilot and not something stamped on the prop hub.
Gary
For those that like to read:
http://www.epi-eng.com/propeller_technology/selecting_a_propeller.htm
For those that like sound and pictures:
https://www.youtube.com/watch?v=uzhPkrx_q2U
Numbers may have meaning but comparing these two props via their manufacturer's stated diameter and pitch isn't straightforward. In the end it's engine power vs observed static rpm, rate of climb, and cruise airspeed that matters to the pilot and not something stamped on the prop hub.
Gary
PerryB
FRIEND
Chico, CA
Exactly. It's fairly easy to calculate using Bartoli's Principle.
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
This one?
or this one?
Images plagiarized from http://bado-shanai.net/Map of Physics/mopBartolisRelativity.htm I've no clue what they mean.
Then again, maybe it's turbo encabulator time again:lol: https://www.youtube.com/watch?v=Ac7G7xOG2Ag
or this one?
Images plagiarized from http://bado-shanai.net/Map of Physics/mopBartolisRelativity.htm I've no clue what they mean.
Then again, maybe it's turbo encabulator time again:lol: https://www.youtube.com/watch?v=Ac7G7xOG2Ag
Last edited:
PerryB
FRIEND
Chico, CA
Well that blew up in my face. I had no idea there was a Bartoli, or that he had any principles. I was sitting around, bored, and came up with this wonderful idea to yank your chain a bit. The "Bartoli's Principle" was a complete fabrication on my part. I pulled the name out of thin air. I figured it was a complete dead end and you'd naturally have to ask "What is it?" Then I would gleefully anounce to the world that it was something I created just to mess with you. And I was so proud of myself.
** I actually took a few minutes trying to invent a name that sounded plausible as that of an early physicist/scientist/mathematician. Damned if I didn't succeed.
** I actually took a few minutes trying to invent a name that sounded plausible as that of an early physicist/scientist/mathematician. Damned if I didn't succeed.
Last edited:
I think this one needs to go to bed...put to rest....put out to pasture...whatever...being a teacher I understand the math, however it cannot be as simple as the pathagrian therum so to speak. We got three planes sitting here at Valdez, all similar but different...
All three running a form of O320. All Running 84x37 at times-All running 31” BW- none of our engines are basic 150hp engines.
Plane 1- Exp Producer- off the ground fast...100’ Plane on the heavy side empty—-1200 if I remember. Cruise 90@2400
Plane 2-Exp super Wide Cub - off the ground fast 90’ Plane is Light empty-1045—Cruise 88@2400
Plane 3-Cert PA18- off the ground 85’ -90’ Plane is 1150 empty-cruise85@2400
There are many variables that you can not punch into a calculator in terms of cruise or takeoff factors...wings, drag, cruise weight...by the way my cub seems to cruise the fastest when heavy...myself and passenger, gear, two or three deer, and I am grabbing 90+ if I get her trimmed just right...kinda like being on step...can’t put that in a calculator.
I would love To have Mr. Catto show up at the Valdez Fly inn with a pile of demo props....love my 84x37....but would like to try a 84x35....82x39....
cheers everyone....
All three running a form of O320. All Running 84x37 at times-All running 31” BW- none of our engines are basic 150hp engines.
Plane 1- Exp Producer- off the ground fast...100’ Plane on the heavy side empty—-1200 if I remember. Cruise 90@2400
Plane 2-Exp super Wide Cub - off the ground fast 90’ Plane is Light empty-1045—Cruise 88@2400
Plane 3-Cert PA18- off the ground 85’ -90’ Plane is 1150 empty-cruise85@2400
There are many variables that you can not punch into a calculator in terms of cruise or takeoff factors...wings, drag, cruise weight...by the way my cub seems to cruise the fastest when heavy...myself and passenger, gear, two or three deer, and I am grabbing 90+ if I get her trimmed just right...kinda like being on step...can’t put that in a calculator.
I would love To have Mr. Catto show up at the Valdez Fly inn with a pile of demo props....love my 84x37....but would like to try a 84x35....82x39....
cheers everyone....
Rob
MEMBER
AZ06
Amen brother Ron,
I can't believe this one is still running? I offered a simple solution way back at post # 94. The Props being discussed here vary as much as as the tides in a year. The simple fact that NONE of them run at exactly 100% should be all the reason a person needs to realize that they will not all perform equally. Suggesting that they should all measure out the same and reconcile is a convenient way to ignore that they are not all created nor consequently will they perform equally. And that's just the props, let alone all the other individual characteristics of an airplane or how the atmosphere may affect each propellor differently.
That was the question... Maybe he should have asked if 'A' catto was a better fit than 'B' Catto?
I can't believe this one is still running? I offered a simple solution way back at post # 94. The Props being discussed here vary as much as as the tides in a year. The simple fact that NONE of them run at exactly 100% should be all the reason a person needs to realize that they will not all perform equally. Suggesting that they should all measure out the same and reconcile is a convenient way to ignore that they are not all created nor consequently will they perform equally. And that's just the props, let alone all the other individual characteristics of an airplane or how the atmosphere may affect each propellor differently.
That was the question... Maybe he should have asked if 'A' catto was a better fit than 'B' Catto?
BC12D-4-85
SPONSOR
Fairbanks, AK.
Not much info on float ops. Still waiting for that after the water gets wet in Alaska and Canada. On-step performance then climb and cruise.
Gary
Gary
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
Ron and Rob, agreed. No doubt the pitch numbers are proprietary for each manufacturer, and are valuable mostly for comparing within one line of props, but not necessarily between manufacturers or maybe even prop models. The word "honest" is an unfortunate choice in this case, because of its implications of other than objectively accurate.
Just for grins, a few minutes ago I calculated the angle at various stations for my 8242 Mac, assuming it's a perfect screw at each station and assuming my assumptions are correct (Perry, don't say it - you had your chance). Tomorrow I'll go measure and report how close (or not) the actual prop is to those hypothetical angles.
This can be very interesting stuff, except if emotions muddy the discussion.
And Ron, thanks for correcting my spelling of puhtagureein.
Just for grins, a few minutes ago I calculated the angle at various stations for my 8242 Mac, assuming it's a perfect screw at each station and assuming my assumptions are correct (Perry, don't say it - you had your chance). Tomorrow I'll go measure and report how close (or not) the actual prop is to those hypothetical angles.
This can be very interesting stuff, except if emotions muddy the discussion.
And Ron, thanks for correcting my spelling of puhtagureein.
skywagon8a
MEMBER
SE Mass MA6
J5ron, Just for the fun of it using any of your three airplanes, keeping them as light as possible place enough ballast at the tail post to move the flying CG back to 20" (rear CG limit). Then tell us what the take off distance and the cruise speed are.
skywagon8a
MEMBER
SE Mass MA6
This one cleared it all up. If you had posted this at the beginning we could have reduced most of the heated discussion. :roll:
Beartooth Fencing
Registered User
I bought a 84 34 Cato and it’s performance is not that impressive I’m not sure why but it’s not that great
Please expand...airplane, hours power ...details...thanks
Beartooth Fencing
Registered User
It’s an experimental supercub. With 30 hrs since a major. It’s an o320 a2 b I’ve got another Cato off a o340 that came off a carbon cub that’s 50 pitch I like it way better than this 34 pitch . The 34 gets off the ground quicker but that’s about it .
roxiedog13
Registered User
Agree wholeheartedly. I assume this is how you come to the conclusion a 38 " pitch prop mysteriously can cruise close to what a borer 45 pitch can . If this works for you
excellent. :lol:
Since a 38" pitch cannot cruise like a 45", obviously the 38" is not correct. Catto even explained this clearly, so for simplicity I just add 3-4" to their published numbers and carry on.
I think what is at issue here is simply those that don't want to admit Catto is misrepresenting the actual effective pitch for cruise, instead want to believe there is some kind of superior
design process happening that beats out all the other "lesser" propellers.
Catto is a descent prop indeed, for experimental that is. Has a number of characteristics that make it a good choice for those that use it . For any "experimental" that requires a better
performing climb prop the Catto offers a fantastic solution, especially the longer props with a finer pitch. No other make a 84"-90" that I am aware of , for out of the hole performance
it's the prop to have. For others that require certified, a bit more cruise and the weight for C cof G considerations there are plenty of other options.
roxiedog13
Registered User
A 34" pitch Catto has to be considered as a 37/38" pitch for cruise considerations. That seems like a poor option for any O-320 IMHO. It should come out of the hole amazing and literally hang off the prop in climb, BUT when you level out this will seriously overspend the engine most definitely . So tremendous pull , poor cruise .
A Catto prop that matches the Borer 82 42 commonly used on the O-320 150HP is the the 84 36 . The 84 37 catto is best suited for the 160HP . A friend of mine with 3000 hours of cub time has the Borer 82 43 on his 160HP also has the Catto 84 37 .
The Catto is only 2150 static yet pulls and climbs slightly better, in cruise the Borer cruises slightly better .
If you what better cruise Catto also offers 82" props. The 82" 42 may be a better choice , the longer props are literally geared for climbing and do that well .
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
Is it tomorrow yet? I computed 9 1/2 degrees at the prop tip, and just now measured it at a little over 9 deg. Over 30 deg near the hub. Nothing precise or particularly definitive about this, just thought it could be fun to compare measured angle with computed angle.
