Odd wheel behavior with new Mk2 parts?

[I_Killed_Jeb]

Have others noticed excessive instability/veering off the runway with nose gears attached to Mk2 parts? I've specifically had issues with nose parts, i.e. cockpit and adapter. These two are exactly the same except the nose gear placement.

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When I was first building spaceplanes with the new update I figured I was just making poor use of new parts but it seems to me that it's specifically an issue with these part types not having a straight surface for the wheel to attach properly in line with the rest of the craft. In fact I've gotten planes to stop the death veer by simply taking the nose gear off the runway!

[Levelord]

The further away the wheel is place from the center of torque, the more unstable it is. This is because the attached parts tend to wobble and bend ever so slightly at their attachment points and it gets worse the further away the attached points are.

Placing the wheel under the cockpit where the torque is generated allows the torque to act directly to the wheel instead of having to go through several other parts. It works for the front wheel and not the rear wheels, because the front wheel is the steering part.

[I_Killed_Jeb]

There is no input on these meaning there should be no torque generated anyway. Moreover this is just a quick example piece, I've noticed similar behavior on longer planes where suddenly the problem disappears with placement on a straight part

[The_Rocketeer]

I think u might be underestimating the weight of your craft. Most of the time rolling instability is caused by misalignment, but that misalignment can be caused by overloading the nose gear. The new SP Mk2 parts are rocket fuel parts, whereas the old were jet fuel. I may be wrong, but I think the oxidiser adds a considerable amount of mass. When you move the nosewheel backward it redistributes the plane's mass between the gears with less bias to the nosewheel.

Having said all that, some surfaces on some parts just don't like to make x-axis alignments. I'm desperately trying to think of a good example but my memory's letting me down again. Anyway, I find the solution is often to rethink your wheel-plan or add another nose-wheel. Gears are massless parts anyway.

Edit: Another thought. When you move the gear back, you also increase the plane's angle of attack (the angle the wings tip upwards from level), which has the effect of increasing the overall lift. Once you have even a little speed, that extra lift will make substantial reductions to the load on the wheels. Again, the mass/load distribution could be the whole problem.

There is no input on these meaning there should be no torque generated anyway.

Mathematically speaking, there's no real difference between reaction wheel torque generated by a cockpit module and aerodynamic torque generated by flaps and control surfaces. This is another good reason for not having the nose wheel so far forward, as it increases the distance from the centre of torque, i.e. the elevons.

Edited November 12, 2014 by The_Rocketeer

[I_Killed_Jeb]

I think u might be underestimating the weight of your craft. Most of the time rolling instability is caused by misalignment, but that misalignment can be caused by overloading the nose gear. The new SP Mk2 parts are rocket fuel parts, whereas the old were jet fuel. I may be wrong, but I think the oxidiser adds a considerable amount of mass. When you move the nosewheel backward it redistributes the plane's mass between the gears with less bias to the nosewheel.

Having said all that, some surfaces on some parts just don't like to make x-axis alignments. I'm desperately trying to think of a good example but my memory's letting me down again. Anyway, I find the solution is often to rethink your wheel-plan or add another nose-wheel. Gears are massless parts anyway.

Edit: Another thought. When you move the gear back, you also increase the plane's angle of attack (the angle the wings tip upwards from level), which has the effect of increasing the overall lift. Once you have even a little speed, that extra lift will make substantial reductions to the load on the wheels. Again, the mass/load distribution could be the whole problem.

I know how to build planes, I have been building SSTOs from scratch without problem for many moons now; I think these surfaces are the main problem as they aren't really taking the load I'm used to them taking. Maybe I'm just imagining them

[The_Rocketeer]

I know how to build planes, I have been building SSTOs from scratch without problem for many moons now; I think these surfaces are the main problem as they aren't really taking the load I'm used to them taking. Maybe I'm just imagining them

Certainly wasn't suggesting that you don't know what you're doing, but you asked the question. Without exploring the avenues of possibility, including your own understanding, you're not likely to find the answer.

[I_Killed_Jeb]

Certainly wasn't suggesting that you don't know what you're doing, but you asked the question. Without exploring the avenues of possibility, including your own understanding, you're not likely to find the answer.

You are correct, I apologize if I came across as testy; haven't had my morning coffee yet .

[Hodo]

Have others noticed excessive instability/veering off the runway with nose gears attached to Mk2 parts? I've specifically had issues with nose parts, i.e. cockpit and adapter. These two are exactly the same except the nose gear placement.

http://imgur.com/a/uxncR

When I was first building spaceplanes with the new update I figured I was just making poor use of new parts but it seems to me that it's specifically an issue with these part types not having a straight surface for the wheel to attach properly in line with the rest of the craft. In fact I've gotten planes to stop the death veer by simply taking the nose gear off the runway!

The problem I am seeing is the rear wheels are out of camber. The angle they are at is why you have that random turning issue with your wheels. KSP does not handle wheels canted at odd camber angles compared to the ones that are straight up and down.

[I_Killed_Jeb]

The problem I am seeing is the rear wheels are out of camber. The angle they are at is why you have that random turning issue with your wheels. KSP does not handle wheels canted at odd camber angles compared to the ones that are straight up and down.

I've never had issues with rear wheels like this in the past; in fact may people build this way as well from what I can see in the exchange. How would this explain the change seen from changing only the front wheel placement.

[LethalDose]

I've never had issues with rear wheels like this in the past; in fact may people build this way as well from what I can see in the exchange. How would this explain the change seen from changing only the front wheel placement.

I'd be curious to see the people you've seen build that don't have a problem with that wheel set-up (e.g. links, vids, etc). It's always implicated as a problem for control of planes on the ground.

Moving your front wheel probably changed the weight loading on all the wheels, specifically putting more weight on the rear cambered wheels and exacerbating the problem.