Can you use RCS build aid to help with making VTOLS

[ScytheElement]

I saw that the mod had a feature for engines instead of RCS, could you use this to make a VTOL?

Edited February 5, 2015 by ScytheElement

[RainDreamer]

There is no reason why not. Just remember to balance the vehicle for both vertical take off engine and for the flying engine. Put them into stages, the lowest stages engines got considered by RCS build aid first.

[Hodo]

I saw that the mod had a feature for engines instead of RCS, could you use this to make a VTOL?

Yes, yes, yes!

It is almost a must for VTOLs. It is invaluable for the proper balance of the vertical part of the flight, even when the craft is near empty it should be balanced. If not you should have enough RCS thrust to be able to maintain level flight while hovering.

[capi3101]

I use RCS Build Aid; I find it an exceptionally useful tool for building planes in general. The big feature of the mod is the dry center of mass calculation - it'll tell you based on your current craft design just exactly how much your center of mass will shift as you burn fuel and it will show you where the CoM will be at that point. With that information you can set a center of lift that will keep your plane's flight stable in all configurations, or use it to make adjustments to reduce (or better yet eliminate entirely) the amount of the shift. The other thing it'll show you is how much torque your thrusters and engines will produce. That's the crucial bit for VTOLs, of course; if your vertical engines produce too much torque, your flight won't remain stable. I haven't played around with this feature of RCS Build Aid all that much as far as building VTOLs, but it does come in handy for small craft with which you want to conduct rendezvous and docking operations.

Something you might consider as you build your VTOL - turn the thrust limiter on your horizontal engines down to zero as you're placing the vertical engines; that way your center of thrust indicator will show you only what's going on with the vertical engines. That will help you find the spot where they need to be placed. Just don't forget to turn the thrust limiter on the horizontal engines back up when you're done. Having a 100% balanced plane helps as well, though you're generally okay if the shift is minimal (say 0.02 meters or so).

DocMoriarty's KSP Space Plane Construction and Operation Guide has a section on how to build, test and fly VTOL craft. It's from 0.24.2 so there are a few things about the guide that are out of date, but mostly it's just data about the lifting body (aka Mk. 2) aircraft parts; the general principles it contains remains sound. Just if you need ideas or pointers there.

[Tank Buddy]

Absolutely, you just need to bring up the RCS Build aid UI in the VAB/SPH and change "translation" to "engines". It will then display the torque about the CoM caused by the engines. You can switch between DCoM and CoM while building to balance with and without fuel.

[ScytheElement]

I use RCS Build Aid; I find it an exceptionally useful tool for building planes in general. The big feature of the mod is the dry center of mass calculation - it'll tell you based on your current craft design just exactly how much your center of mass will shift as you burn fuel and it will show you where the CoM will be at that point. With that information you can set a center of lift that will keep your plane's flight stable in all configurations, or use it to make adjustments to reduce (or better yet eliminate entirely) the amount of the shift. The other thing it'll show you is how much torque your thrusters and engines will produce. That's the crucial bit for VTOLs, of course; if your vertical engines produce too much torque, your flight won't remain stable. I haven't played around with this feature of RCS Build Aid all that much as far as building VTOLs, but it does come in handy for small craft with which you want to conduct rendezvous and docking operations.

Something you might consider as you build your VTOL - turn the thrust limiter on your horizontal engines down to zero as you're placing the vertical engines; that way your center of thrust indicator will show you only what's going on with the vertical engines. That will help you find the spot where they need to be placed. Just don't forget to turn the thrust limiter on the horizontal engines back up when you're done. Having a 100% balanced plane helps as well, though you're generally okay if the shift is minimal (say 0.02 meters or so).

DocMoriarty's KSP Space Plane Construction and Operation Guide has a section on how to build, test and fly VTOL craft. It's from 0.24.2 so there are a few things about the guide that are out of date, but mostly it's just data about the lifting body (aka Mk. 2) aircraft parts; the general principles it contains remains sound. Just if you need ideas or pointers there.

Wow thanks for all the great information, I really appreciate it.

[capi3101]

No problem, and thank you for the rep.