Shock Absorbers

[Slam_Jones]

First off, if this has been suggested already, my apologies. My searches on the subject turned up very little.

What my suggestion is, is rather simple. Lander legs have a form of suspension built in, right? Basically, why not mod a shock absorber part?

Basically, it would have two attachment nodes: top and bottom. Top stays solid, while the bottom can move upward into the top one, absorbing shock, similar in the way landing legs do so.

You could use this in a number of ways, but the main one I am think of is on rovers. Basically, attach shock absorber to the frame at the top, then a small cubic strut or something to the bottom, and the wheel attached to that, allowing the wheel to get the effect of suspension.

Has this already been done, and/or is it feasible? Would new modules be required to handle it?

Edited September 12, 2015 by Slam_Jones

[RidingTheFlow]

Landing legs already have suspension which is spring + shock absorber.

If there would be no shock absorber, lander will never stop wobbling after spring compresses - but it does.

Or are you suggesting a part which is suspension element but with 2 attach nodes instead of 1? This would be useful, but AFAIK in current versions legs can't handle anything attached to them - I remember somebody saying its physics limitation. But its very probable when 1.1 released it may as well change that.

Edited September 12, 2015 by RidingTheFlow

[Slam_Jones]

Landing legs already have suspension which is spring + shock absorber.

If there would be no shock absorber, lander will never stop wobbling after spring compresses - but it does.

Or are you suggesting a part which is suspension element but with 2 attach nodes instead of 1? This would be useful, but AFAIK in current versions legs can't handle anything attached to them - I remember somebody saying its physics limitation. But its very probable when 1.1 released it may as well change that.

Exactly! My inital idea was just to take a landing leg itself and modify the cfg file to allow attachment to the "foot" of it, as it were, but without it needing to deploy to make use of it. If that makes any sense

[clivman]

We need airbags......

[Mad Rocket Scientist]

Good idea! In the mean time, use ant engines.

[Starwhip]

Good idea! In the mean time, use ant engines.

Spider engines are even better springs. You can radially attach them to other Spider engines, and then whatever goes on the opposite end (Say, a wheel) to the top Spider.

(Spider = LV-1R, the radial version of the Ant)

EDIT:

Works best if you clip the spiders inside one another. 5 is a good base.

[Mad Rocket Scientist]

Spider engines are even better springs. You can radially attach them to other Spider engines, and then whatever goes on the opposite end (Say, a wheel) to the top Spider.

(Spider = LV-1R, the radial version of the Ant)

EDIT:

Works best if you clip the spiders inside one another. 5 is a good base.

Oops, I meant spider.

[sumghai]

In order for this feature to implemented, the game needs to be able to properly handle the relative motion of two or more connected parts, which is no easy feat.

In KSP, the position and orientation of parts on a craft/vessel are defined relative to the root part, and at the moment, if one part moves or gets destroyed, adjacent parts don't get affected. This is why, for instance, you cannot current attach parts to cargo bay doors and expect them to also move when the doors open and close. For a part to move relative to another, its position and orientation values must thus be updated constantly to ensure smooth motion - in effect, you end up rebuilding the vessel constantly every time you move an appendage and any parts connected to it. This is pretty much the secret behind how InfernalRobotics works.

Back in 0.24, Squad had in fact experimented with a secret ModuleJointMotorTest PartModule, which would allow two or more parts to move relative to one another. AFAIK this has never worked reliably, as over time, the joints and adjacent parts gradually drifted apart after repeated use, possibly due to floating point errors.

Until Squad solves the problem behind ModuleJointMotorTest (or somehow integrates InfernalRobotics into the stock game), stock robotic arms, shock absorbers or any other mechanical linkages where parts on a vessel move relative to each other will not be possible, at least in the forseeable future.