Good day to you. And, winglets.

[BillWiskins]

Hello sirs and/or madams. I\'ve been lurking for a week or two, and I have decided to reveal myself like a lost carrot, majestically materialising in the sink as the dirty water drains away.

Or something like that. Anyway I have been playing for just over two weeks and I ama satisfied with my progress to date - achieved flight, then orbit, then never-ending rampage off into the Sun, then Mun orbit, then Mun explosions (so pretty), and most recently, Mun landing. And this is where I have encountered a problem.

Now, before you panic, I don\'t want to know how to land on the Mun - that I can do. The thing is, I\'ve got about 27 guys up there waiting for rescue, or a cake delivery, or something to make life just a little bit not bleak, so I have to find a way to fix my landing.

Currently, while it is easy enough to get the command module down without killing anyone, I just can\'t seem to persuade any of the rest of my lander to survive with it. I\'m only using stock parts, and my most robust design boils down to the command module, a decoupler (which usually survives as well. Useful.), two RCS tanks and eight RCS thrusters.

I just can not land on those RCS tanks. So, I decided in a flash of inspiration, I\'d use winglets to act as lander legs (just like a million other people have been doing already. I\'m on the ball, me). I chose the fancy ones that pivot as you fly, supposedly for stabilisation.

Thing is, adding these to my existing design (which works perfectly for what I\'m lobbing at the Mun so far - easy to fly, simple to build, blah blah) causes it to start acting like a cat which has been given such a surprise that it has forgotten what it\'s legs do. It wobbles all over the place, eventually flipping itself over uncontrollably. It\'s quite hilarious, however many have died trying to tame it.

Right now it\'s fine without those silly wingletlegs on just a single SAS unit. I\'m hesitant to replace it with an ASAS because of how perfectly it seems to handle (and use fuel), and also because I\'m a bit lazy. My main question (and congratulations on getting this far. I don\'t really do succinct) is this: why do these winglets cause such a drastic change in behaviour? It\'s definitely them causing the issue, and for a part that was supposedly to be added for stability, it has me rather confused.

http://t.co/dikzwlQi - this would be the vehicle in question, in case it\'s useful.

My apologies if this has come up before and I\'ve not been paying attention.

[socket7]

The winglets probably move the crafts center of gravity forwards and make the rocket unstable.

Might I suggest popping over to the addon parts section and grabbing yourself a lander leg of some sort? They are lighter, more durable, and not as aerodynamically prone to changing your center of gravity.

I promise to keep the forum wolves from eating you alive and calling you a cheater for using non stock parts. 8)

[BillWiskins]

I don\'t know man, it just seems so...impure... I\'ll promote it from \'no way, not at all, never!\' to \'if it gets to over 36 stranded Kerbonauts, I\'ll do it - for their sake\'.

Actually, an update: I just tried the same design with an ASAS in place of the SAS, and it made a huge difference.

The difference being that the vehicle shook itself apart a few seconds after lift-off, with winglets, with the other type of winglets, or without winglets. Can that be right? I\'m going back to the SAS, and the prospect of endless hours trying to touch down at 0.00001m/s so as not to pop my RCS tanks and strand even more brave men up there on the Mun.

There must be a better way! Maybe.

[Hypocee]

In general winglets at the nose of a craft create instability. Barring a fundamental redesign, my first recommendation would be in the lines of 'fight fire with fire': Stick more winglets on the back. The stabilizing torque they create will hopefully override the unstable torque created by your 'legs'.

The aerodynamic model is simple enough right now that fins are purely additive and don\'t need to be in clear air. How much you want to exploit that is an aesthetic consideration An initial tip: Stick your fins to the centermost thing you can, or can bear to. Fins with flexible lever arms tend to a different kind of amusing instability.

[Gojira]

also

The RCS tanks are explodey because they have their center point on the bottom.

FIX THIS.

[NovaSilisko]

acting like a cat which has been given such a surprise that it has forgotten what it\'s legs do.

Quote of the month, December \'011

[BillWiskins]

A Quote of the Month in my first post? Why thank you kind sir!

Well, I got myself some aftermarket add-on legs, even though it made me feel dirty. Sadly, I was so busy sanitising my WASD fingers that I miscalculated and gave that silly old Mun another crater.

I thank you all for the recommendations, and I assure you they will be thoroughly tried and tested if it means I get to land with my original design, or something close to it.

[BillWiskins]

I must say, I\'m very grateful for your assistance here folks. Another set of four fins and the Meredith 10 quit her acrobatic tendencies cold turkey. She still wants to lean one way or the other while under SAS, but I was able to achieve this:

http://t.co/k9ZuG4GF

Just need to sort out my fuel management a little so the guys can get home again, but I\'m pretty pleased. Cheers!

[dbellmo2]

Hello sirs and/or madams. I\'ve been lurking for a week or two, and I have decided to reveal myself like a lost carrot, majestically materialising in the sink as the dirty water drains away.

Or something like that. Anyway I have been playing for just over two weeks and I ama satisfied with my progress to date - achieved flight, then orbit, then never-ending rampage off into the Sun, then Mun orbit, then Mun explosions (so pretty), and most recently, Mun landing. And this is where I have encountered a problem.

Now, before you panic, I don\'t want to know how to land on the Mun - that I can do. The thing is, I\'ve got about 27 guys up there waiting for rescue, or a cake delivery, or something to make life just a little bit not bleak, so I have to find a way to fix my landing.

Currently, while it is easy enough to get the command module down without killing anyone, I just can\'t seem to persuade any of the rest of my lander to survive with it. I\'m only using stock parts, and my most robust design boils down to the command module, a decoupler (which usually survives as well. Useful.), two RCS tanks and eight RCS thrusters.

I just can not land on those RCS tanks. So, I decided in a flash of inspiration, I\'d use winglets to act as lander legs (just like a million other people have been doing already. I\'m on the ball, me). I chose the fancy ones that pivot as you fly, supposedly for stabilisation.

Thing is, adding these to my existing design (which works perfectly for what I\'m lobbing at the Mun so far - easy to fly, simple to build, blah blah) causes it to start acting like a cat which has been given such a surprise that it has forgotten what it\'s legs do. It wobbles all over the place, eventually flipping itself over uncontrollably. It\'s quite hilarious, however many have died trying to tame it.

Right now it\'s fine without those silly wingletlegs on just a single SAS unit. I\'m hesitant to replace it with an ASAS because of how perfectly it seems to handle (and use fuel), and also because I\'m a bit lazy. My main question (and congratulations on getting this far. I don\'t really do succinct) is this: why do these winglets cause such a drastic change in behaviour? It\'s definitely them causing the issue, and for a part that was supposedly to be added for stability, it has me rather confused.

http://t.co/dikzwlQi - this would be the vehicle in question, in case it\'s useful.

My apologies if this has come up before and I\'ve not been paying attention.

:-\ .... Samuel Clemens is that you?

http://en.wikipedia.org/wiki/Mark_Twain

RE Fuel Issue: My biggest problem was not having enough fuel to get home. At the time my lander had one stage, and I used it to slow the lander, land the lander, and take back off. I incorporated a 'braking' stage that slowed my lander down and allowed for some minor orbital corrections. Once the lander was slowed down and low enough I detached from the de-orbit stage and used the lander to land ... then I used it to take off and get me on my way home.

Post Script:

It\'s possible to get home with just RCS.

[BillWiskins]

I know it is possible, because I have poured so much concentration and effort into trying to make it happen that even if it wasn\'t previously, then by now some mystic mind-conjured forces will have made it so.

So far, though, no successful return trips for me. In the picture previously posted, I actually ran out of RCS juice at about 5 metres above the landing altitude. Anger was displaced by bemusement as the fins failed to shatter, and then the dread set in as I realised I\'d have to fiddle the design and launch a Meredith 11.

There has been a more recent attempt, but due to a minor time-warp miscalculation I regained control around 4,000 metres up, and travelling at the kind of speed that you often travel at when you aren\'t 4,000 metres from something very large and rock-based. So, the landing was about as successful as a chocolate helicopter would be, and the Mun didn\'t even look up from what she was doing.

Onward, and to more wasted fictional lives!

P.S., I can confirm that I am not Mark Twain, on the grounds that his facial hair would just crush mine in a battle.

[NovaSilisko]

I like you, Mister Wiskins.

[BillWiskins]

Thank you, Mister Silisko. I think I will enjoy writing things in this Internet Place.