Launch clamps: Advice?

[MarvinKitFox]

I have a slight problem in that when I build really heavy boosters, they don't fly very well.

No not the usual Wobblies, overheats, or ka-blooyies... Its those dang LAUNCH CLAMPS.

I have a problem on the launch pad.

Over a certain size, one rather *has* to use the launch clamps, instead of just standing your rocket on its engines.

Also, with a big enough rocket, its not enough to support just the lower edge. I find that I need to support the upper stages too, especially those over 100m height. (hehehe. i did say big)

I often run into this teensy problem.

Is there any way to cause the launch clamps to retract, stand further away, or otherwise avoid snagging on my lower stages?

Or will i simple be forced into building smaller, orbital assembly, and other such non-kerbalesque behaviors?

I have tried (and use) the idea of launch clamp support from below, usually through a decoupler. But this is often not enough.

When a launch clamp decides to go along for the trip, the mass is almost negligible, but the off-center torque of a long swinging pole is very hard to compensate, and besides, often they rip stuff off, rather than uprooting themselves.

Any bright ideas?

(Not mods for bigger rockets, welding parts, or quantum struts please. I know about those, and use when appropriate. This is a campaign of BTSM, so I try to keep cheats to a minimum)

Edited March 23, 2014 by MarvinKitFox

[Awaras]

You could try this mod:

http://kerbalspaceprogram.com/fasa_launch_towers/

It's just the launch clamps from the FASA mod...

No idea how they will integrate themselves with the BTSM techtree, though. :/

Might take some fiddling to get them to appropriate tech tiers.

Edited March 23, 2014 by Awaras

[Sirrobert]

You could try to put some Girders Against the side of the upper parts of the rocket, and attatch the launch clamps to those?

I never tried that, so no clue if it'd work.

You should be able to put some radial decouplers between the rocket and the girders to ditch them after takeoff?

[Awaras]

You could try to put some Girders Against the side of the upper parts of the rocket, and attatch the launch clamps to those?

I never tried that, so no clue if it'd work.

You should be able to put some radial decouplers between the rocket and the girders to ditch them after takeoff?

BTSM places radially-mountable girders really, really high up the tech tree, so that won't help much... :/

[Skorpychan]

Try sticking sepratrons on the clamps, or simply strutting them to the rocket further up.

[Kasuha]

Launch clamps should not travel with you when you lift off. They should either separate, or hold your ship near ground. At least I have never seen a launch clamp flying except when a mod caused that. So my guess is that some of your mods may be causing this or your ship's structure is broken (e.g. due to excessive number of parts or inappropriately applied symmetry modes).

[MarvinKitFox]

Try sticking sepratrons on the clamps, or simply strutting them to the rocket further up.

Ok, that not only works, it works GREAT. (Struts from the clamps to wherever)

Cannot believe i never tried it before, thanks!

[MarvinKitFox]

Launch clamps should not travel with you when you lift off. They should either separate, or hold your ship near ground. At least I have never seen a launch clamp flying except when a mod caused that. So my guess is that some of your mods may be causing this or your ship's structure is broken (e.g. due to excessive number of parts or inappropriately applied symmetry modes).

The launch clamp was attached to the orange tank, much higher up. It disconnects correctly, twangs out and then back in... Just as the top of those SRB's is passing by. It is simply snagging on the passing rocket.

The extreme rocket blast near the bottom may also be forcing the top inwards, as the launch clamps do tend to fly all over the place. Less than half of the clamps remain standing after a big launch like this.

Same behaviour stock, and under various mods.

[Rabada]

I recently started putting my launch clamps as close as I can to the center of mass for the entire rocket. It has been working extremely well, the rocket is mostly balanced when it launches, so it always goes straight up.

[Sargent890]

You could try to put some Girders Against the side of the upper parts of the rocket, and attatch the launch clamps to those?

I never tried that, so no clue if it'd work.

You should be able to put some radial decouplers between the rocket and the girders to ditch them after takeoff?

That's what I do. It works well, but you'll probably need stuts between the girders and the rocket.

[Gravitas Shortfall]

When a rocket launches, the upward force is being applied to the bottom of said rocket by the engines of the first stage, and that first stage has to be able to support everything above it whilst under a force of >1 g. Thus any rocket capable of making it off the ground should, at least in theory, also be able to be supported by launch clamps attached only beneath the first stage engines. The vehicle in the screenshot isn't too much smaller than my largest launcher, which I support on the launch pad by means of 3 launch clamps placed below a fuel tank placed below a decoupler placed below each of the 19 first stage mainsails.

[Kasuha]

That is true in theory, in KSP though the rocket is put on launchpad in exactly the same form as it was in VAB (i.e. as if it is in orbit) and then physics (and gravity) is turned on, resulting in shake which is much more violent than the liftoff as joints find their balanced position in gravitational field. So it is often better to add some more support to prevent the rocket breaking up during that.

Hopefully devs will do something about it sometime.

[Kryxal]

Besides, it's tough to clamp the INSIDE of the rocket, so you end up with clamps on the outside taking all the weight. Now that I think about it, I wonder if you could use those girders and clamp the upper stages, then detach THOSE clamps (or the girders they're attached to) before anything else ... just use them to get through the physics loading, that is.

[Kasuha]

You can also put decouplers below your engines and put clamps below these decouplers. That allows to support the whole bottom of the rocket (as long as you can put the decoupler there, so not possible for aerospikes or the upcoming NASA engines).

[HoustonDave]

You can also put decouplers below your engines and put clamps below these decouplers. That allows to support the whole bottom of the rocket (as long as you can put the decoupler there, so not possible for aerospikes or the upcoming NASA engines).

Now that is not something I ever considered. What a brilliant idea. Dummy tanks below the first stage engines for clamping purposes. Just wow.