Two grabbers. One flipping.

[shelshok]

I'm trying out having multiple grabbers on arms, and while they both seem to attach, one always flips backwards. Is this normal, and is there a way to avoid it?

I'm using restock parts in these images, but it also happens with stock parts. It also happens whether the arms are built with symmetry or separately.

Edited July 25, 2021 by shelshok

[Snark]

Moving to Gameplay Questions.

34 minutes ago, shelshok said:

I'm trying out having multiple grabbers on arms, and while they both seem to attach, one always flips backwards. Is this normal, and is there a way to avoid it?

... How sure are you that they are, in fact, both attaching?  I wouldn't be surprised if it's actually physically impossible to have two attachments like that, given the tree structure that KSP imposes on ships.

(I would have guessed "not possible", but I've never actually tried it and for all I know maybe they put some sort of special-case code in there to handle it.)

[RealKerbal3x]

4 minutes ago, Snark said:

... How sure are you that they are, in fact, both attaching?  I wouldn't be surprised if it's actually physically impossible to have two attachments like that, given the tree structure that KSP imposes on ships.

(I would have guessed "not possible", but I've never actually tried it and for all I know maybe they put some sort of special-case code in there to handle it.)

Well, given that docking with multiple docking ports simultaneously is possible, it'd make sense that multi-grabbing would work too (or maybe it doesn't, I'm unfamiliar with the technical details of how klaw grabbing works and whether it's at all similar to docking).

[Mythos]

17 minutes ago, RealKerbal3x said:

Well, given that docking with multiple docking ports simultaneously is possible, it'd make sense that multi-grabbing would work too (or maybe it doesn't, I'm unfamiliar with the technical details of how klaw grabbing works and whether it's at all similar to docking).

When docking multiple ports, there is stilll only one in the proper state "Docked", defining the tree structure. Others might be docked as well, and thus holding things together, but there is a special state "Docked (same vessel)" for that.

I have seen many docking/grappling problems, but I'm also not sure if grappling hooks do have a state "Grappled (same vessel)". Maybe there is, but it might be very difficult to achieve, because there is no magnetic force helping to align and have multiple attach at the same time with sufficient force.

[shelshok]

50 minutes ago, Snark said:

... How sure are you that they are, in fact, both attaching?  I wouldn't be surprised if it's actually physically impossible to have two attachments like that, given the tree structure that KSP imposes on ships.

Here's a video with first just one and then both attached. Also shows the flipping happen...

https://imgur.com/a/Ibn6l32

Mechanically, it seems to work as expected. Just not visually.

Edited July 25, 2021 by shelshok

[shelshok]

47 minutes ago, Mythos said:

When docking multiple ports, there is stilll only one in the proper state "Docked", defining the tree structure. Others might be docked as well, and thus holding things together, but there is a special state "Docked (same vessel)" for that.

I have seen many docking/grappling problems, but I'm also not sure if grappling hooks do have a state "Grappled (same vessel)". Maybe there is, but it might be very difficult to achieve, because there is no magnetic force helping to align and have multiple attach at the same time with sufficient force.

Looks like they do. These are the two ModuleGrappleNodes in the sfs.

MODULE
{
	name = ModuleGrappleNode
	isEnabled = True
	stagingEnabled = True
	state = Grappled
	dockUId = 3684687629
	grapplePos = -0.456129104,0.42180261,-0.397637904
	grappleOrt = 0.77568686,-0.468438506,0.422936171
	grappleOrt2 = -0.508752942,-0.860675693,-0.0201938152

 

MODULE
{
	name = ModuleGrappleNode
	isEnabled = True
	stagingEnabled = True
	state = Grappled (same vessel)
	dockUId = 3684687629
	grapplePos = 1.49011527E-07,0.50418061,4.47034608E-07
	grappleOrt = -1.49011612E-08,1.00000012,-8.94069672E-08
	grappleOrt2 = 0,8.94069672E-08,-1.00000024

 

[Mythos]

36 minutes ago, shelshok said:

Looks like they do. These are the two ModuleGrappleNodes in the sfs.

Very nice to have this confirmed.

And yes, since something weird did happen to your claw, it seems to have its state changed. So I would have guessed it did attach and that bug is just visual.

[shelshok]

Yeah, so it seems any same vessel grapples flip for me. Doesn't matter in which order they were used. Just that they are the same vessel.

 

 

 

EDIT: Figured I should try without mods. Same result: https://imgur.com/a/1FQPhj9

Edited July 25, 2021 by shelshok

[Mythos]

50 minutes ago, shelshok said:

Yeah, so it seems any same vessel grapples flip for me. Doesn't matter in which order they were used. Just that they are the same vessel.

So maybe that is the kind of precise information you could do a bug report with. Maybe someone still cares 

[shelshok]

30 minutes ago, Mythos said:

So maybe that is the kind of precise information you could do a bug report with. Maybe someone still cares 

Done.