Autostruts, locked autostruts, and robotic parts - a discussion

[Superfluous J]

There are a lot of threads and posts about autostruts and robotic parts. Some of them deal with autostrutting, and others with wheels having locked autostruts. I'd like to bring the discussion into one place so we can figure out what's supposed to happen, what does happen, and how to (if necessary) file a bug report.

I'll start. If you turn on "Visualize Autostruts" as described in this thread, you'll see some... interesting results.

Note the line does not go to the heaviest part but instead goes to the piston. This seems to be by design.

When the craft is launched and the pistons extended, they work as you'd expect because the autostrut does not change. Ignore that the craft is upside-down. It's not a very good craft.

But when you go back into the VAB and turn the piston around, and then re-launch it, you see that extending the piston changes the length of the autostrut on the fly.

All this seems to be coded within the game so autostruts work even when put on robotic parts. However, in some circumstances they don't seem to work like this, and I think that's a bug. But I don't know if it's one because I'm actually having a lot of trouble recreating the problem.

I'd like to know others' experiences. I'll be playing around more and will post my own.

[Superfluous J]

From some quick testing, I've found that IN GENERAL things with autostrut will just stop if, on their way through the ship tree on the way to the target part, they find a robotic part.

However, so far I've seen odd behavior when that autostrutting is to heaviest part. When the heaviest part has no robotic parts, you strut to it. Like before. But, under some circumstances, you just don't get an autostrut. If you strut to root or grandparent, it works as above, but for some reason, under some circumstances, strutting to "heaviest" just doesn't get a strut at all. I think it may have to do with radially attachments to other robotic part but I'm not sure.

So to get good autostrutting chains, you need to tell every robotic part between the think you're strutting from and the thin you're strutting to, to autostrut to that thing so you continue the chain all the way from the remote part to the root, or the heaviest part. And there's a chance that autostrutting to the heaviest part will be broken along the way. This does not work a lot of times as you frequently chain robotic parts to other robotic parts, and then you're just autostrutting across a part-to-part connection, which doesn't actually help. The whole point in strutting is to make triangles and this just makes a line.

Also, they will chain through regular struts. I think possibly the game always did this we just couldn't see it until now

(more to come, hopefully)

Edited June 2, 2019 by 5thHorseman

[JohnTomato]

Disabling autostruts on ModuleWheelBase module (using this code from a 3 y/o thread) does not work in the sense that the GUI still says "Autostruck Locked: Heaviest Part" and there's no change regarding the wheels' behaviour to hinges.

[KerikBalm]

I had a design where the heaviest part was on robotics, and they wouldn't move. When I lowered their fuel amount and added something heavier then they could move

Parts with a robotics between them and the root part seem to have their autostrut stop at the robotic part. I'm not sure the opposite is true. A part with no robotics between it and the root part may autostrut to the heaviest part on the other side of robotics... at least that's what I think is going on

[FleshJeb]

I’ve been under the impression that strutting or autostrutting across the moving portion of a robotic part prevents movement, unless it’s strutted to something that can move identically. You can strut from the base portion of the part freely.

@5thHorseman any new discoveries?

So far, I’ve been able to brace my tilt-rotor pods by placing a u-joint (servo and two hinges) and a piston on the main craft, and a u-joint on the pod. I place them facing each other, and run a conventional strut between.

[Superfluous J]

2 hours ago, FleshJeb said:

 

@5thHorseman any new discoveries?

Nothing new, but I've confirmed a lot that autostruts just don't cross robotic parts. Regular struts will cross them but are more permanent. I've not yet found a good stock way to get both motion and strutting.

EVAStruts works in 1.7.1 though so yay

[Snark]

On 6/2/2019 at 10:53 AM, 5thHorseman said:

This seems to be by design.

On 6/9/2019 at 5:46 PM, FleshJeb said:

autostrutting across the moving portion of a robotic part prevents movement

Yes, otherwise the robotic part wouldn't be able to move because the autostrut would jam it in place.

On 6/2/2019 at 11:05 AM, 5thHorseman said:

From some quick testing, I've found that IN GENERAL things with autostrut will just stop if, on their way through the ship tree on the way to the target part, they find a robotic part.

On 6/3/2019 at 1:12 AM, KerikBalm said:

Parts with a robotics between them and the root part seem to have their autostrut stop at the robotic part.

On 6/9/2019 at 7:49 PM, 5thHorseman said:

autostruts just don't cross robotic parts

In general, yes.  But if you lock the robotic part, it allows autostruts to pass through.

 

[Superfluous J]

1 hour ago, Snark said:

Yes, otherwise the robotic part wouldn't be able to move because the autostrut would jam it in place.

...even though they seem to have extendible autostruts already implemented, even if by accident. The strut in this picture changed length as I extended the piston.

[archnem]

As far as I can tell from my limited experiments, SAS control doesn't pass thru robotic parts either unless they're locked.