Weight

[spaceman1999]

So how do you test weight capabilities of your rockets? Do you use dummy payloads or mods?

[The Destroyer]

Fuel tanks. Lots and lots of fuel tanks.

I only started building lifters in 0.22. Before that, I built the launcher specifically for its payload.

[MockKnizzle]

I design my rockets around a specified payload mass with Kerbal Engineer. No need for trial-and-error testing. If I didn't have engineer available, then I'd work out the math myself.

[Dust]

I design my rockets around a specified payload mass with Kerbal Engineer. No need for trial-and-error testing. If I didn't have engineer available, then I'd work out the math myself.

This. I've always built my crafts as a whole, with intended payload included, using KER to tell me how confident I should be that it'll work.

[spaceman1999]

So you would recommend Kerbal Engineer?

[Whackjob]

I build the payload first, then build more rocket around it until it gets where I want it to be.

[Madrias]

I tend to build spaceplanes around the payload that I want to bring up. Disposable winged probes happen to be a great way to build stations. Dock to the Station Core, undock the probe, re-enter and pop chutes. I've built cargo planes with mod parts where I shipped up large chunks of station. I've made stackable spaceplanes where I was docking 5 or 6 planes together to make a primitive substation.

With 0.23.5, I've tried rockets and shipped large multi-segment cores up.

[Jouni]

I use a spreadsheet for quick sketching, before starting to build the rocket. It's much faster than trial and error in VAB with KER or MechJeb.

[cantab]

Fuel tanks make good dummy payloads. There's nothing but mass there, so you can be sure all the control is from the launcher itself. Plus you can then feed the test payload fuel to the top stage engines and ram it into the Mun at ludicrous speed.

The only thing to watch for is length; real ships of the same mass might be longer and thus harder to handle. That caused an issue when launching my asteroid tug.

If I'm building a launcher, I'll usually place a payload fuel tank first, then build the launcher below it. That way I can drop the launcher as a subassembly: IIRC you can't drop your entire rocket as one.

I use KER to check my stage TWRs and delta-V. If you're doing it manually, a viable shortcut is to stick what you have on the pad and get a mass readout from the map view, saves you totting up all the parts individually. Then subtract the fuel and oxidizer in the tanks you're using; make sure you don't count the payload tanks by mistake.

[RocketPilot573]

I typically test to see how must my lifters can lift, for example, my shuttle can lift 10 tons to LKO.

[Hans Dorn]

I feed my kerbals extra snacks to stress test new designs.

[SkyRender]

I used to hand-calculate the TWR and dV. Nowadays I let Kerbal Engineer do it for me, to save time. During release interim when KER doesn't work yet, I just go by past experience for what they can handle.

[Brotoro]

I've made some standardized rockets, then tested them to see what they can lift into orbit. When I have a payload of a certain mass, I grab the appropriate launcher.

Although recently I've designed my payloads with the lifting capacity of my most-used launcher in mind. If I need something heavier in orbit, I launch it in parts and dock them together.

[MKI]

I do it like the Russians

Build a launch System use it until something breaks or doesn't work for one of my missions. Until then it stays as is with minor modifications for different missions.

[CtrlAltEL1TE]

I put on a dumby payload then observe TWR / Delta V numbers supplied with KEngineer or mechjeb. When i feel im right on the edge of an LKO payload with Dv I attempt to launch the payload.

[karolus10]

So how do you test weight capabilities of your rockets? Do you use dummy payloads or mods?

I often use mass simulators with guidance unit and fuel tanks, You can adjust fuel levels (so bad that fuel load aren't displayed as fuel mass, but you can get around it easily as one unit is 5 kilograms, both LF & OX) to quickly get any mass you want, It's more flexible solution with less part complexity involved.

Also it allow design You launch vehicle and payload separately.

EDIT_1:

If tanks with multiple fuels/resources would came up I would be glad to see "sand" as one of choices, it would be very simple and elegant solution of making dummy payloads !

Edited April 10, 2014 by karolus10

[RocketBlam]

I started by building the lifter after the payload. When I started doing complex asparagus lifters I started saving them as subassemblies, in stages. So I have a Stage 3 heavy lifter, a Stage 2 Heavy, a Stage 2 Medium, etc. Then you just tweak them for your payload.

[SpaceSphereOfDeath]

I have a few really overpowered subassembly launchers, one can lift ~250t to LKO. (Without payload it had 12000m/s of deltaV)

[magnemoe]

I do it like the Russians

Build a launch System use it until something breaks or doesn't work for one of my missions. Until then it stays as is with minor modifications for different missions.

This is far more plausible in 0.235 than before, with the stronger joints you don't have to build the boosters around the cargo but can put it below.

I uses mechjeb to tell me dV and TWR so the only real need to test is the stability.

[Mesons]

Fuel tanks. Lots and lots of fuel tanks.

I only started building lifters in 0.22. Before that, I built the launcher specifically for its payload.

I only use launchers if I'm doing lots of repetitive launches of similar payloads, like when building a space station. Otherwise, I still build every rocket from the ground up. I like to go through the engineering phase with every mission. Besides, needing to ditch half a leftover orange tank that I cant use (like if it's covering a docking port I need) hurts me inside.

[Accelerando]

I put more stacks of fuel and engines on it until it works. individual TWR of 2 for each stack is preferable.

[Seret]

So how do you test weight capabilities of your rockets? Do you use dummy payloads or mods?

I don't. I build the payload for the mission (I start with a spreadsheet), then add enough rocket to get the necessary ÃŽâ€v to get it into space. Designing an actual launcher for your payloads isn't hard if your payloads are sensibly sized. It's the last little job I do before launch time.

[Skorpychan]

I use KER, but actual testing is done by just launching heavier and heavier craft, until something pops off or the whole thing fails to get into orbit.

But for the most part, my payloads are as standard as my lifters.

[Heagar]

I normaly build my lauchers by "feeling" of how much dv a certain payload will use up to get into an orbit. And therefore build a bit on the conservative side witch ends up in a rocket with more dv than actual needed.

But if you are in the need to test your rocket with an dummy-payload i would suggest one of these mods instead of fueltanks. That's because with these you can test your launcher mutch more accurate:

Weights

Surface Mounted Counterweights

Dummy weights

[karolus10]

But if you are in the need to test your rocket with an dummy-payload i would suggest one of these mods instead of fueltanks. That's because with these you can test your launcher mutch more accurate:

Well, after fuel inside tanks are tweekable You can adjust tank weight very precisely (+/- 5kg), but I guess that dedicated parts may be more about convenience.