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dire

Is there some trick to getting Klaws to flex?

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OK, so a picture is worth a thousand words: 2ZC5eKt.png

 

Obviously, the center of mass for this craft is...a little off from the center of thrust, and at anything better than nominal thrust it starts spinning like a top. It -started- with a lot of RCS fuel, but it's mostly empty now and there isn't much by way of SAS on it....all things to add on my next design. Now, it's held together with 3 Advanced Grabbing Units, but I can only seem to get one of them to flex properly. In theory that's probably enough to move the CoM over the center of thrust but it would be a lot easier if I could get the other two joints to pivot. Is there some trick I'm missing? I've switched to other craft, reloaded the save and the game, changed control spots. I haven't tried decoupling the craft and recoupling (simply because it was so very painfully slow the first time to couple them).

The simple way to test if the klaw pivot is working is to toggle torque off for half the craft, free that pivot, and then perform maneuvers. The expected result is that the parts with no SAS enabled should flop around almost at random.

Edited by dire

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Myself and others have been having an issue with the Klaw since 1.1.3

Doesn't seem like this bug is affecting everyone, as I haven't heard much complaining about it.

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If you just take it slow, SAS will get you there eventually.

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Ran into this problem with a land train prototype. I was going to use claws to connect the cars, but couldn't get them to flex. Here's some imgur for you:

 

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1 hour ago, dire said:

I can only seem to get one of them to flex properly.

...can you be a little more specific?  What exactly is thwarting you?  Does nothing happen when you click the "unlock joint" button, or what?

Also, one thought:  why are you pushing the load?  Any long, skinny, multiply-jointed thing tends to flop around and have CoM alignment problems when you push it-- even when it's docking ports instead of the klaw and supposedly everything ought to be perfectly aligned.

I see that your "tug" looks like it has a trailing klaw pointing backwards-- why not grab hold with that, and pull the load?  You can just leave the joint unlocked, and the "trailer" will just naturally swing into the needed alignment behind the "tractor".

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Nothing seems to happen when I unlock the joint, even if I turn off SAS and accelerate.

I am pushing the load because I docked using mostly main thrusters and didn't have enough torque and control to be confident that I could flip the craft on approach. All those giant monoprop containers are over 95% -empty-. And I just tried doing a simple undock, flip, redock -- don't have enough monoprop for that.

Am thinking about launching something like a Big Orange and like 5 SAS units and docking that to this mess just to give me a little control over my orientation. Or deleting them from the tracking station; each of those ships has completed its primary mission and while I'd -like- to dock them up with Mun Command and refuel them, it's not critical if I don't.

Edited by dire

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I use the klaw a lot, but I don't do asteroids (at least not yet). So I almost never free the pivot. I suspect there are a lot of people like me. :wink:

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15 hours ago, dire said:

I am pushing the load because I docked using mostly main thrusters and didn't have enough torque and control to be confident that I could flip the craft on approach. All those giant monoprop containers are over 95% -empty-. And I just tried doing a simple undock, flip, redock -- don't have enough monoprop for that.

Except that one of the features of using the Klaw to "dock", rather than actually docking using docking ports, is that you don't have to get things perfectly aligned, and therefore don't need to use RCS at all.

Here's how to rearrange your current craft from a "push" to a "pull" configuration, without needing to use any monopropellant at all:

  1. Tractor releases its klaw, to disconnect from trailer.
  2. Tractor sets the trailer as its target, and makes sure the navball is in "target" mode.
  3. Rotate tractor to point away from trailer. (Ideally, straight away, but doesn't have to be exact.)
  4. A very gentle nudge from the tractor's main engines to send it drifting away from the trailer.  Slowly, i.e. under 1 m/s.
  5. While tractor is drifting away, rotate it 180 degrees so that it's pointing perfectly target-relative-velocity retrograde.  Easy to do, just center the appropriate navball marker.
  6. When the tractor gets a reasonable distance away-- a few dozen meters, say 30 or 50-- use a gentle nudge of the main engines to completely kill its relative velocity to the trailer.
  7. Switch to the trailer.  Rotate it so that its long axis points as precisely as you can towards the tractor.
  8. Switch back to the tractor.
  9. If necessary, rotate it a bit to make sure it has the pink-circle target marker perfectly centered in the navball crosshairs.
  10. Give it a gentle nudge of the main engine to start it going straight towards the target.  Slowly, i.e. under 0.5 m/s.
  11. Arm the aft klaw.
  12. Rotate the tractor 180 degrees so it's pointing directly away from the trailer, i.e. the aft klaw is pointing straight at it.
  13. Wait for them to drift together and connect.

No mono needed.  RCS is only needed for bringing ships together when you need to super-fine-tune the lateral position, which generally only matters for docking ports.

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So the answer is "The klaw is broken." The kraken strikes!

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