Technical aspect of building good planes

[MisterCrow]

Trying to make my first, mid-sized plane. I can make it work, but I can't seem to get anywhere near the fuel efficiency and speed of the excellent "Buffalo" posted by Sir Murtak (and other propeller planes) on the workshop.

I have the same number of engines (2 medium engines), a similar sized plane, max RPS of the engine set the same, and same / similar gear ratios and number of gearboxes. Propellers both have the same number of blades too and my wings are over the CoM.

What's the magic trick here that I'm missing? I can't get the plane to take off with the RPM set so low, yet Buffalo can take off with ease. I need much higher RPM to get the plane to take off.

Furthermore, I really don't understand the front wheel mechanics. When I gather speed, my front wheel (which is used to steer the plane when grounded) randomly get stuck full lock left or right, veering the plane off the runway. What is dictating this behaviour? I checked my build compared to the Buffalo and the wheel mechanics are exactly the same.

Is there a good guide somewhere on building planes? All I can find is tips on how to make them look good or just simply make them fly - but I need to understand the mechanical / engineering aspect of plane building in Stormworks. For example, do wings have any effect in game - do they actually provide lift like in real life? Do the size of the wings matter? Do I need to use the special wing blocks that apparently "cut" through the air?

Many thanks

[Ra-Ra-Rasputin]

Have you checked those prop pitches? It's easier for the engine to run at a lower, or gradually increasing prop pitch, and the prop pitch value really changes how the plane flies.

The other things that change how a plane flies is 3 factors:
1.) The spread, and arrangement of any control surfaces, both active and passive
2.) The amount of wing area, and their relation to the center of mass
3.) The drag of the tail fin

And yes, wings do provide lift, but so does the entire body. You can have some absurd designs that fly well when the balance of wings and control surfaces is set correctly.

https://steamcommunity.com/sharedfiles/filedetails/?id=2007150795

This, for instance (ship body not mine, but the flight system is) is capable of very stable flight (so long you control the pitch) and flies in air exactly like a boat would, using the rudder.

Try it out. As soon as it bounces itself off the water, hit the flight button, stabilize, and simply turn using the rudder. The wings are really only there to provide more resistance to rolling and a little bit of glide time to make hitting the prop button easier, they're not necessary for flight.

[MisterCrow]

By prop pitches do you mean the collective of the props, or their vertical angle (i.e. putting them on a hinge to make them go up and down)?

Also, with regards to your 3 factors:
1) What's the best spread and arrangements of control surfaces? Where should I put passive control surfaces?
2) Big wings = more lift?
3) How do I reduce this? make the fin smaller?

That creation is mad lol! It flies, but you have to hold down the special button for the prop to work!

Any ideas about the dodgy front wheel? Extending the wheel further seems to make it worse

[Ra-Ra-Rasputin]

Prop pitch is the collective of the prop, yeah. The technical term is prop pitch, i just can't stop referring to it as such.

1) It depends what the control surface does, and whether it's passive or not. Keep in mind that "control surface" does not necessarily mean you're not controlling it directly, or it ever even moves. It's just something that changes aero(or hydro-)dynamics. Generally, they're more effective the further they're away from the center of mass, but they can also destabilize it if you do it carelessly.

2) Big wings generally is more lift. Keep in mind that wings directly in line with center of mass contribute very little to resistance in pitching, because well, they're at the center of mass. This is why most planes' wings are swept backwards (and rarely forward).

3) In most cases you want to increase this. Naturally in planes there is a lot of air flowing over the tail, and it is far, far away from center of mass, making it not only excellent in flight characteristics, but also allows very lightweight, stable and uncomplicated landing gear, known as taildraggers

https://en.wikipedia.org/wiki/Conventional_landing_gear

[MisterCrow]

Thanks. I got a working plane now (wheel problem solved by using the big pivot instead of small). Expanded the rear tail a fair bit and added on two more control surfaces - seemed to do the job.

Still not able to get the performance and fuel consumption that the Buffalo has though. No idea how Sir Murtak's managed that. I can only get about 110 k/n out of my plane with similar fuel consumption to the Buffalo. Other than add more engines, I've no clue how to get more speed. The Buffalo reaches 210K/n with RPS set to just 7 per engine. I've set my engines to 12 RPS, which is about as low as I can manage, whilst being able to take off.

[Ra-Ra-Rasputin]

Up your gearing! He could also be using numerous methods like minor clutch slipping and all that. Hard to say without looking at your plane in person

[MisterCrow]

mmmm I've tried fiddling around with gears. If you fancy taking a look, I've uploaded here.

Obviously it's nowhere near finished yet!

Thanks :)

[MisterCrow]

After 5 hours of tinkering, I've now finally worked out how Sir Martak has got such performance out of his plane. He's edited the xml file. I can see the engine's "max-force_scale" is set to 9, as opposed to the default of 1 in the xml file. No wonder I couldn't match the performance of his plane!

This is pretty much cheating IMO.

It's been a frustrating evening, but I'm glad I've FINALLY worked out what the hell is going on...

[Jorg Hammond]

Thing is, if you edit his plane's xml file to set the variable back to the default, I suppose it will fly horribly.

So you possibly not so much have matched his design like you intended at the start, but rather come up with a better one.

Congrats!

[Ra-Ra-Rasputin]

Oh, that's absolutely cheating, that cheatyface!

So he has engines essentially 9 times as powerful as the rest of us. What a daft teat. Such a good find there