Spot the Design Flaw! - a KSP related forum game

[Evanitis]

Rules: You post a picture of a craft you built, and the following user should tell what's wrong with it. Than he needs to posts his own flawed design, so the circle continues. If you never make mistakes, you can't play - sorry.

We aren't looking for minor inconveniences like a too heavy engine or Sub-optimal TWR. We need flaws that possibly results in a failed mission.

 

Let me start with an easy one - a classy VTOL I made this morning. It's intended to lift a certain bulky ~150t object.

Edited February 12, 2016 by Evanitis

[Spartwo]

Lack of SAS?

[Matuchkin]

2 hours ago, Spartwo said:

Lack of SAS?

Lack of landing gear.

Hold on, Ill post my image later. You guys continue chatting.

[Spartwo]

Lack of gear doesn't seem too bad as long as the landing is sufficiently soft.

[Tex_NL]

Really? Nobody is seeing what's wrong with this design?
I won't spoil it for you but it is rather obvious.

[cubinator]

1 hour ago, Tex_NL said:

Really? Nobody is seeing what's wrong with this design?
I won't spoil it for you but it is rather obvious.

Spoiler

If I recall, the Goliath does have a "Reverse Thrust" feature so it wouldn't actually stop it from working. If you were to drop it from a plane and try to land it it would, but since it's a VTOL I doubt it would be launched from a plane.

 

[insert_name]

it looks like theres an engine not staged with the rest

[cubinator]

12 minutes ago, insert_name said:

it looks like theres an engine not staged with the rest

I think that's an engine in the back for horizontal propulsion. The lower six are all staged together.

[quasarrgames]

1. yellow fuel lines on top are useless since jets draw fuel from all stages

2. DEFINATELY not enough SAS considering how heavy that thing is, and how hard it is to land with jets

3. that claw probably can't handle the weight or the impact alone. With cargo that heavy, that's like having a mainsail thrusting against that thing.

4. Here's the kicker: not enough TWR. Goliaths can give 360kn AT MOST each. with a payload of 150 tons, and that ship weighing at least 50 tons itself, that gives it a thrust to weight ratio that barely passes 1. Add to that the fact that reverse thrust gives less power, and the fact that the jets are significantly angled, and that thing'll probably never get off the ground. 

I rest my case.

 

[CAKE99]

This one is harder.

[p1t1o]

1 hour ago, CAKE99 said:

This one is harder.

Looks like you've got 3 solids arranged at 90 degrees to each other? Bad news for launch!

[max_creative]

1 hour ago, p1t1o said:

Looks like you've got 3 solids arranged at 90 degrees to each other? Bad news for launch!

To be exact, 3 RT-10 "Hammer" Solid Fuel Boosters on 3 TT-70 Radial Decouplers placed on a FL-T800 Fuel tank.

[CAKE99]

2 hours ago, p1t1o said:

Looks like you've got 3 solids arranged at 90 degrees to each other? Bad news for launch!

 

4 minutes ago, max_creative said:

To be exact, 3 RT-10 "Hammer" Solid Fuel Boosters on 3 TT-70 Radial Decouplers placed on a FL-T800 Fuel tank.

There's still one moar problem.

[p1t1o]

Is that a single fin I can see there?

[max_creative]

Oh no I see! Where the 4th booster should be there's a random TT-38K Radial Decoupler.

[StrandedonEarth]

4 hours ago, CAKE99 said:

This one is harder.

I don't see a parachute in that staging list....

[CAKE99]

23 minutes ago, p1t1o said:

Is that a single fin I can see there?

 

2 minutes ago, StrandedonEarth said:

I don't see a parachute in that staging list....

Yes! All 3 issues have been detected!

Now someone needs to post something new, it's 2:30AM, I watched too much anime 

[max_creative]

11 minutes ago, CAKE99 said:

 

Yes! All 3 issues have been detected!

Now someone needs to post something new, it's 2:30AM, I watched too much anime 

I looked at the staging. You still have a random TT-38K Radial Decoupler.

[CAKE99]

11 minutes ago, max_creative said:

I looked at the staging. You still have a random TT-38K Radial Decoupler.

There are 4 radial decouplers, only 3 of them have boosters.

[max_creative]

Yeah. 3 TT-70's and 1 TT-38

[0111narwhalz]

Bit harder, this one.

[max_creative]

It's rocket engines are not on the CoM.

[cantab]

I doubt it has enough rocket thrust to make orbit, and it looks like the lower jets may be prone to tailstrikes, but otherwise I'm not sure what the problems are.

[max_creative]

The front and back have different cross sections?

wait! There's no gear!

[0111narwhalz]

3 hours ago, max_creative said:

It's rocket engines are not on the CoM.

Suprisingly, they're pretty close to the CoM. Barely any pitch during circ burn.

3 hours ago, cantab said:

I doubt it has enough rocket thrust to make orbit,

Well, the rockets are actually torch drives, so...no.

3 hours ago, cantab said:

and it looks like the lower jets may be prone to tailstrikes,

And that's one of the most grevious of its issues.

3 hours ago, max_creative said:

wait! There's no gear!

Not the greatest of shots to show this, but the center fuselage has some of BD's adjustable landing gear. You can see one of them just under the nose in the second shot. It has two more just forward of the ramp.

3 hours ago, max_creative said:

The front and back have different cross sections?

Although a relatively minor issue, that does seem to affect the drag profile of the vessel rather severely.

Actually, the biggest problem is pitch authority. Those wings are just too big back there, with too little control surface. I need bigger canards, I think. Also, super tiny ailerons don't help. Tried to do a launch from the runway, turn around, and come back, but I think I'd be better off circumnavigating. Heat's also a problem; ascent is conducted by modulating the throttle and watching the temperature on the cockpit, even after I added cheaty radiators concealed within the structure.

Edited April 4, 2016 by 0111narwhalz