Lifting an awkward load

[ZeeWulf]

So, I made an Armadillo.

Okay, I'm torn between calling it a Beagle or Aardvark, but it's basically an Armadillo; I wanted to use those gigantic rover wheels, and I wasn't getting enough torque to get up the crater sides on the Mon. Unfortunately, the rocket I attempted to build to lift said rover shredded itself within moments of launch (TWR so tight I had to run 7 mainsails at full power on the base stage, second stage was running a Mainsail, 6 large SRBs, and 6 of the FL15 or whatever engines..) and I'm having trouble trying to find a way to hold this thing together.

Here's what the rover looks like, just so you can get an idea of just how wide this load is:

Any suggestions?

[lammatt]

38.3t wouldnt be too hard to lift

but the challenge here is the off-center center of mass (if it has one) and the wobbling

just put some counter weight on the ship which you can dump when the rover lands

you generally dont want a center of mass not inline with the principal axis of the ship.

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u probably want to strut the wheels with each other and then the bottom pair should be strutted to the lifter and a couple struts from the nose to the lifter will be nice too.

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i play with Nova punch...38.3t is very easy indeed

but if you insist on stock it'll be a lot harder...but i think my approach will be using a lot of solid boosters to provide the first couple or two thousand m/s of dV (~10000 km) before swithing to liquid rockets always

and then 6 mainsail on 2X9m tank (orange + 400) in asparagus + a single orange tank at the central stage with a skipper would probably be enough to get into orbit or even enough to get to minmus

Edited August 7, 2013 by lammatt

[DChurchill]

Yeah you'll need to strut the crap out of that thing. Off center CG will be difficult, too without a counterweight like lammatt said.

38 tons shouldn't be hard, though.

Here's some idea of what I do with struts for heavy and wobbly payloads:

It's a design from .20 that I don't use anymore, but the thing is so top heavy that it shreds itself on the gravity turn without the struts. I probably have some better examples, but not here at work.

[Captain Sierra]

My Nova I lifter can do 40 tons to the Mun and is all stock. It is a single asparagus setup running 7 mainsails and progressively drops them. I assume you know asparagus. All 7 tank stacks are the same and as follows: fl-600-32 (whatever the double sized tank is, same as in pic above), orange jumbo 64, another 600-32, mainsail. Set that up in hexagonal asparagus. add reaction wheels (and maybe RCS) where needed to get the thing to be controllable. If you follow this perfectly and create a near perfect Nova I remake, I'll be damned if it doesn't work.

[allmhuran]

750 tons using a thrust plate, stock parts only. Also good for awkward payloads like yours ZeeWulf:

Tutorial (pretty simple really):

Edited August 7, 2013 by allmhuran

[ThePsuedoMonkey]

An easy way to deal with off-center payloads is to use the radial attachment point below its CoM, and build your lifter on that instead of the original attachment point. One way to check if the radial attachment point is lined up is to enable clipping, put a rocket on it, flip it upside down, and show the CoM and the thrust vector; if the vector goes through the CoM it's in the right position.

[stallion x1]

wow thats reaaly amazing 750 tons is huge......

[Monkeh]

Here's what I did when faced with a very similar design. All stock parts. 1016 Mg.

15 mainsails. 1st stage drops 8. 2nd drops 4. Last one 2. All asparagus staged.

Bit of a cow but it lifts anything you like.

Then the whole lander becomes the rover/rocket powered buggy to get you where you need to go

It's got a little rocket pushing it forwards, retract the legs and away you charge

Is this too many pictures for a forum post? Let me know if it is please, thank you.

The start of Munbase Monkeh.

"We're all going on a Munar holiday..

No more working for a, year or two!"

Yes, I am overly proud of my new creation, I apologise, let me know if you want have a look at the .craft file.

Good luck.

Edited August 7, 2013 by Monkeh

[ZeeWulf]

Thank you all for the layouts; I ran with the Nova (modified with miniboosters to aid in separation because i kept having the other tanks take out engines), but discovered two fatal flaws:

1. I forgot to run a fuel line to the descent/landing engine

2. I need an upper maneuver/braking stage.

Poor Merdon. Probably shouldn't have stowed away on the thing in the first place....

[Wesreidau]

Cut it in half with docking ports and assemble the vehicle in orbit. Oh yes, heresy, I know. On a side note, I would take that nose cone off the cupola so you can drive the vehicle from IVA.

[Tarrow]

but the challenge here is the off-center center of mass (if it has one) and the wobbling

Offset center of mass can be worked around - I've been using a couple of action groups of Rockomax 24-77's to handle the center of mass shifts on a shuttle-style launcher (all the major weight changes during launch being on the SRB / liquid tank assembly slung below the orbiter). Works nicely as long as I don't accidentally activate or deactivate the wrong group.

Whats your delta v requirement for the launcher? Does it have to get to another planet or just haul the lander up to orbit so it can be picked up a long-distance-optimised transporter? If it's just to orbit then it's doable with one mainsail (on an orange tank - this is the asparagus core) and four skippers (1st drop pair orange tank + x200-16, 2nd drop pair orange + x200-32).

edit - added pic

http://i110.photobucket.com/albums/n92/tychocaine/screenshot10_zps6b3a12e1.png

Edited August 7, 2013 by Tarrow