Yet another mass balance thread - girders vs wings this time...

[RidingTheFlow]

Girders too heavy or wings too light? Allow me to illustrate:

How is this possible? Not to say that girder is much smaller in size, that wing should have a same structural lattice inside it. Unless wing made of styrofoam, it can't be 50% lighter.

I was quite surprised when I found its much more efficient to build large interplanetary ship skeleton out of wings.

[tater]

Masses seem to have not gotten any sort of balance pass in KSP. Look at the mk3 cockpit vs the mk1-2 capsule, for example. You are spot-on.

[waterlubber]

Girders are pretty heavy. Wings seem about right.

[Red Iron Crown]

Girders in spacecraft should be made of lightweight materials, I agree that the girders are way overweight in comparison to the wing parts, especially when you consider their heat resistant properties.

[Starwhip]

Don't forget that the girder can take an 80 m/s hit while the wing can only take around 12. (Maybe 6).

I agree that a mass balance would be nice, the cockpits do not make any sense at all.

[Claw]

Don't forget that the girder can take an 80 m/s hit while the wing can only take around 12. (Maybe 6).

Yes, this. There are several parts in KSP that follow this sort of convention. The Mk1 fuselage (that contains no fuel) compared to an FL-T400 also fits this mold. The Mk1 is heavier, but can also take more impact.

[tater]

The mk3 cockpit is lighter than the mk1-2. It carries more crew. It is vastly larger. It is more impact resistant, more heat resistant, carries substantially more mono, has bigger batteries, and more torque. Everything about it is considerably better, but it is 3/4 the mass.

[RidingTheFlow]

I know girder can take more impact then wing, but it doesn't make much sense either - nothing in it structure/size shows why, as long as they both made of metal. I can understand solid H-beam (not shown here) being more strong/heavy, but not this one which is just lattice made of thin struts.

I'd rather use landing gears/legs for landing. And lattice girders should be best for structure building, not wings.

btw I don't think it's "convention", more likely spaceplanes parts were added after girders without looking at mass difference. Or maybe girder masses were never looked it Would explain why truss lattice girder has same weight as slightly longer solid H-beam.

Edited September 9, 2015 by RidingTheFlow

[CaptainTurbomuffin]

I'd only like to comment about the cockpits. If the plane cockpit had higher mass, it would be EVEN MORE difficult to have an aesthetic delta-wing at the back, due to the CoM moving forward. What I'd like is the Mk 1-2 being more ugile, and long-term, with interplanetary focus on the mk-1-2, and orbital focus on the mk-3. Once we'll have movement inside vehicles, better docking and airlock abilities for the mk-1-2. Once we'll have life support, interplanetary LS-capability for the mk-1-2, while orbital for the mk-3. But until than, Insane durability for the mk-1-2! No heatshields needed for interplanetary return!! Or something like that.