How do you make a balanced, steerable hovercraft?

[Kerbface]

I was trying to make one (using 4 engines for thrust) and it could get off the ground fine but it was hard to get it to balance, in the spaceplane hangar it doesn't seem to count rocket engines as thrust when calculating centre of thrust (I wanted to use rocket engines so it could work on other bodies even without an atmosphere. It wasn't moving, so I couldn't make sure it was at the centre of mass. I'm also guessing using some fuel up would change the centre of mass and possibly unbalance it?

Also, not sure how to move it around carefully in the direction you want to.

Any thoughts?

I'm really new to this game and probably punching above my weight by even trying, but hey.

[HoY]

What most people recommend is to stick to the VAB and Rockets until you get the hang of them, then switch over to the SPH and do inside atmosphere flying. Some people dont like doing it that way but its a little easier to learn

[Kerbface]

What most people recommend is to stick to the VAB and Rockets until you get the hang of them, then switch over to the SPH and do inside atmosphere flying. Some people dont like doing it that way but its a little easier to learn

Yeah, I know, I just really wanted to build a hovercraft. But I'll tell you I've had more success so far with them than with planes. My plane designs so far seem to go into a crazy spin as soon as they take off.

[bulletrhli]

Actually, when talking with a few people, we challenged eachother to do exactly this. If you take a look at the Hybrid Ion Engine mod pack we used those and an assortment of power generators to keep it going. Unfortunately, we all failed at making it stable enough for an enjoyable flight because there is no way to create a counter thrust. What I mean by that is if you tilt forwards, the adjacent engines tend to overpower it and you lose control. If there was a way to vary the thrust on the engines, it would be very easy! I know I won't be of much help, but I suggest you keep trying using lots of lift capable surfaces and balance it out and see how it goes!

[Kerbface]

Is there some way to make the thrusters keep it balanced so it doesn't tilt at all and then use RCS or a different thruster to move it about without tilting the craft? Just to translate it?

[bulletrhli]

At the current time, no because the main engines fire at equal thrust. If you used action groups and something like the radial mounted little tiny orange engines, can't seem to remember their names at the moment, than their small thrust combined with the main engines could counteract it to some point and MAYBE, in theory, make it somewhat more controllable. I implore you to try it and return with your results.

[tommygunyeah]

I would certainly check out the How To forum as that has all the information you need in there

[CalculusWarrior]

I remember trying to make a VTOL craft... It's very very difficult. If your engines aren't all in the proper positions, then your ship will flip out and explode. Also, as it burns fuel it will shift around the centre of mass, making it hard to control. I believe there's a stock hovercraft in the SPH, you may want to check that out for design tips.

[Kerbface]

Does sound difficult to do. For the moment, I've decided to put that to the side and work on making boat/raft to collect some Kerbal's who are currently stranded in the ocean. Not too bad so far.

[Tfin]

My reaction to this subject was, "If you figure that out, let the real world hovercraft manufacturers know."

[cardgame]

A lot of trial and error. I remember making a VTOL plane with RCS thrusters back in 0.13, didn't have mirror symmetry or center of mass indicators to work with then!

I strongly recommend RCS to give you control, only use the engines to counteract gravity.

[Darren9]

Even when you perfectly balance the thrust and mass in the SPH unless the craft is symmetrical as soon as you start to move in an atmosphere the drag effects of different parts have an unbalancing effect. RCS + SAS modules or MechJeb's "Kill Rotation" can make things easier.