big planes and ferram help

[endl]

this is my ssto cargo plane that i would like to deliver to duna i cant seem to make it lift off:

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ive tried playing with the angle of attack it doesnt seem to help, it also makes the ramp too low

also any ideas on how to get something of this nature to fly with a vtol system as well would be greatly apreciated

Edited November 13, 2014 by endl

[Alshain]

2 things.

1. Bring your Center of Lift forward so that the ball is JUST BARELY touching the Center of Mass. This will give you more pitch authority.

2. Move your gear forward so that it is just slightly behind the Center of Mass. This gives you a proper fulcrum. (Don't put it ON the Center of Mass, this will cause the plane to tilt back before you even start the engines).

Alternative to #2, use shorter wheels in the back or mount them so that the plane angled up. This allows a natural lift. A 3rd option is to angle the wings rather than the plane, however that will also affect flight.

As for VTOL... tread carefully. VTOLs and FAR are not all that easy to do. Carrying a giant load, even worse. You need to get your basic design principles down first.

Edited November 13, 2014 by Alshain

[Hodo]

Alshain is dead on with his suggestions.

On a side note, I don't think that craft will make it to Duna and back with its fuel load. The SABER-M engines are not the most efficient engines in space.

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Note how this craft uses LV-1N angines in space to do most of its orbital maneuvers. That craft when I had it could haul 120 tons into an orbit of 100km x 100km, unfortunately I no longer have that craft file.

I am currently rebuilding my career mode to get back to where I can build another monster lifter.

[endl]

it has 4 nukes tucked under the wings the sabers are for orbital insertion. i was thinking i could switch over to nukes for the xfer part, that said moving the COL closer to COM did the trick. seems like the bigger the plane the closer you want to have them spaced. im going to go ahead and mark this as solved but if anyone has any ideas on the vtol approach for this type of plane i would love to hear it

[Hodo]

it has 4 nukes tucked under the wings the sabers are for orbital insertion. i was thinking i could switch over to nukes for the xfer part, that said moving the COL closer to COM did the trick. seems like the bigger the plane the closer you want to have them spaced. im going to go ahead and mark this as solved but if anyone has any ideas on the vtol approach for this type of plane i would love to hear it

VTOL and STOVL SSTOs of this type aren't to terrably difficult. The trick is making sure your CoM and Vertical CoT are perfectly inline no matter the fuel load or cargo load. This may require a mod like TAC fuel balancer. But that craft it wouldn't be to hard to do it with.

B9 has some VTOL rocket engines that work perfect for most non-oxygen planetary landings. I have used them quite a bit in the past.

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This could haul about 72 tons STOVL or 36 tons VTOL into a 100x100 orbit.

You can see that the engines are place far enough out to provide a wide thrust base, and they center the center of thrust through the CoM.

[endl]

VTOL and STOVL SSTOs of this type aren't to terrably difficult. The trick is making sure your CoM and Vertical CoT are perfectly inline no matter the fuel load or cargo load. This may require a mod like TAC fuel balancer. But that craft it wouldn't be to hard to do it with.

B9 has some VTOL rocket engines that work perfect for most non-oxygen planetary landings. I have used them quite a bit in the past.

http://imgur.com/a/UWsRB

This could haul about 72 tons STOVL or 36 tons VTOL into a 100x100 orbit.

You can see that the engines are place far enough out to provide a wide thrust base, and they center the center of thrust through the CoM.

the shifting COM gives me problems and that is far more engines then i can probably fit, i was thinking of something more creative like using KAS to rotate the main engines but with my configuration they hit the ground also they tend to wobble heavily so i was hoping for some ideas on a wing/cargo configuration that could support this design approach like a cv-22 osprey for space basically.

[Hodo]

the shifting COM gives me problems and that is far more engines then i can probably fit, i was thinking of something more creative like using KAS to rotate the main engines but with my configuration they hit the ground also they tend to wobble heavily so i was hoping for some ideas on a wing/cargo configuration that could support this design approach like a cv-22 osprey for space basically.

You mean Infernal Robotics, KAS is just the plugin that lets you attach and remove parts.

That design I posted was something that had way more engines than it needed just incase it had a heavy load. I have some that only have 2 engines, others that have up to 20.

The trick is mainly about balancing the CoM and Vertical CoT. Test out with smaller designs first and figure out what works for you and then scale it up.

[Wanderfound]

the shifting COM gives me problems and that is far more engines then i can probably fit, i was thinking of something more creative like using KAS to rotate the main engines but with my configuration they hit the ground also they tend to wobble heavily so i was hoping for some ideas on a wing/cargo configuration that could support this design approach like a cv-22 osprey for space basically.

As is usual in FAR: let reality be your guide. You'll notice that rotating-engine craft like the Osprey tend to have high-mounted wings in order to to deal with this issue. If you want to rotate engines, mount your wings higher on the fuselage.

For shifting CoM: place your fuel load so as to keep the CoM/dCoM offset below one metre, and use fuel lines to control the order in which they drain. And place your cargo bay as close as possible to CoM. A decent number of SAS units and a few Vernors are also useful for negating minor imbalances.

[endl]

yes i meant robotics sorry, as for the high wing design im aware of that but im limited by the fact that it will block the top cargo bay, but more importantly the engines wobble when mounted to the radial rotatory this makes its very hard to make an osprey that can fly from ground to orbit without eating massive amounts of fuel. (varriant engines)

[Wanderfound]

The wobble I can't help with 'cos I don't use those parts (although: moar struts is the usual solution). As for the wings...well, this is why Ospreys don't have top doors. Any reason not to flip the cargo into a bomb bay instead?

[Kryxal]

You might want to kick in the nukes as well when you go to rockets, it's not like more thrust is going to be a bad thing and they'll be more efficient. Do you actually need 4 nukes, or would 2 be enough?

[Hodo]

yes i meant robotics sorry, as for the high wing design im aware of that but im limited by the fact that it will block the top cargo bay, but more importantly the engines wobble when mounted to the radial rotatory this makes its very hard to make an osprey that can fly from ground to orbit without eating massive amounts of fuel. (varriant engines)

The problem you run into with IR is the wobble. If you strut them it wont rotate, if you dont, they wont stay straight.

[endl]

The wobble I can't help with 'cos I don't use those parts (although: moar struts is the usual solution). As for the wings...well, this is why Ospreys don't have top doors. Any reason not to flip the cargo into a bomb bay instead?

i want to deliver rovers out of it if i make a bomb bay that will limit the height of my rovers because they would have to be able to drive out from underneath

The problem you run into with IR is the wobble. If you strut them it wont rotate, if you dont, they wont stay straight.

yea thats what i was talking about. otherwise id have to slap on more engines which is more mass which is a new plane all together

Edited November 14, 2014 by endl

[Wanderfound]

i want to deliver rovers out of it if i make a bomb bay that will limit the height of my rovers because they would have to be able to drive out from underneath

You're planning a VTOL; drop rover, fly up five metres, hover forwards five metres, land.

yea thats what i was talking about. otherwise id have to slap on more engines which is more mass which is a new plane all together

For a bit of stock-part VTOL and rover-carrying inspiration, see http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1527285&viewfull=1#post1527285 and http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1504987&viewfull=1#post1504987

[Tortoise]

Theres your problem. CoL too far from CoM

[Hodo]

You're planning a VTOL; drop rover, fly up five metres, hover forwards five metres, land.

Or you can do like this. This is a VERY old craft I built back in .21.

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It was a VTOL and was able to cary a rover in its cargo bay.