Prop for 150

[TazmanianDevil]

If you have someone that you can try different props to see what works best, that is what I would do. I was told to go with the 30x12 but on my 37.5% Yak, I found the 32x10 works a lot better.

That's what I used to fly with my 37.5 Yak.
The best all around prop for that airframe.

With all that being said, a major key finding is the type of airframe you're flying.
You can find your self flying with a specific engine with a specific prop on a certain airframe but with that same engine on a different airframe the prop will be different.

 

[CEThomas]

That's what I used to fly with my 37.5 Yak.
The best all around prop for that airframe.

With all that being said, a major key finding is the type of airframe you're flying.
You can find your self flying with a specific engine with a specific prop on a certain airframe but with that same engine on a different airframe the prop will be different.

Yes, I had a 30x12 on my Solution and it worked fine. But on the Yak it just did not cut it. Have been thinking that it may be due to the large cowl on the Yak and the extra 2" out past the cowl.

 

[TazmanianDevil]

Now I'm flying with a different engine, much bigger in a different but same concept plane.
Its the Krill SU 29, and the prop I've seen and try that does the best work for IMAC was the 32-12, for 3D the 31-12.
See the file, its a myth baster as for large cowls.
So thats why the 32-12 is best for that Krill SU 29, big round cowl, the prop Di is bigger than the 33% of the round cowl.

 

[stangflyer]

Now I'm flying with a different engine, much bigger in a different but same concept plane.
Its the Krill SU 29, and the prop I've seen and try that does the best work for IMAC was the 32-12, for 3D the 31-12.
See the file, its a myth baster as for large cowls.
So thats why the 32-12 is best for that Krill SU 29, big round cowl, the prop Di is bigger than the 33% of the round cowl.

This is good information to keep in mind. I am understandably curious what the 3w 3d prop is going to be like on the GP 176 Evo on my Sukhoi. I do like to get an idea of rpm on the ground, but most important to me is how a prop performs in the air. I would think a tick over 6300 on the ground is going to be insane in the air. Especially with the way it pulls on the ground. Will be most interesting for sure.

 

[TazmanianDevil]

Big bore engines shouldn't pass the 6200-6300 static, my opinion only.
higher RPM makes the plane more crisp thats for sure but not too much.

When I fly in IMAC style I want the plane to be like a ballerina, slow, precise and in a zone where I can control every 1/8 of a roll 100% so they need to be slower, the 32-12 let me do that, the plane is so gentle its just make things easier.
3D, I want higher RPM, I want the rolls to be fast and crisp, the 31-12 let me do that...the higher RPM the faster the rolls...thats with my planes I guess its the same with all.
Thing I've learned is that you need to make everything easier.

 

[stangflyer]

Big bore engines shouldn't pass the 6200-6300 static, my opinion only.
higher RPM makes the plane more crisp thats for sure but not too much.

When I fly in IMAC style I want the plane to be like a ballerina, slow, precise and in a zone where I can control every 1/8 of a roll 100% so they need to be slower, the 32-12 let me do that, the plane is so gentle its just make things easier.
3D, I want higher RPM, I want the rolls to be fast and crisp, the 31-12 let me do that...the higher RPM the faster the rolls...thats with my planes I guess its the same with all.
Thing I've learned is that you need to make everything easier.

I am all into the "easy" thing. But I really like the snappiness and such. I like the ballerina effect too. But still, want to be able to get a little crazy. I love watching IMAC. The precision and accuracy is so cool to watch.

 

[3D-Joy]

Interesting discussion.

I have flown my da150 at up to 6600 rpm static. I've seen a guy go close to 7000 static on pipes and a tiny prop. This thing was really impressive to see, throttle response was insane but 7000 is a little out of my comfort zone.
That being said a 150 is not really a big block anyway. Well for that matter none of our toy engines are big blocks either, the only real limiting factor for rpm on 150+cc engines is the prop. Once you go past 31 or 32'' diameter, prop ripping becomes a real issue and we have to keep rpms down to prevent that.

I guess I'll have to give another shot at slow props and see if I can make them work for my plane. I really thought much less people still liked the mej 32x10 or 3W 3D prop.