Problem with Struct Connectors

[VirtualBrain]

Hello community, here's is my problem :

I'm trying to make land on Duna a rover with retros which are attached to each other with Struct Connectors, but when I decouple the rover, the Struct disappear and the retros do not fly away the rover as they should.

So, how can I attach the retros ?

Thanks

 

Edited April 13, 2017 by VirtualBrain

[Alshain]

Can you post a picture?  It sounds like you aren't fully decoupling somewhere.

[bewing]

I'm having trouble understanding how long you want the retros to stay attached to the rover. So you will also need to list the steps for how you want it to work with the retros.

1. Rover begins attached to mothership.

2. Mothership enters Duna orbit.

3. Rover decouples from mothership?

4. ... then what?

 

[Alshain]

41 minutes ago, bewing said:

I'm having trouble understanding how long you want the retros to stay attached to the rover. So you will also need to list the steps for how you want it to work with the retros.

1. Rover begins attached to mothership.

2. Mothership enters Duna orbit.

3. Rover decouples from mothership?

4. ... then what?

 

I suppose I could be mistaken, but it sounds like he is trying to fashion a sky crane landing.

[bewing]

Agreed. So I think the main problem is that the OP doesn't understand that struts are merely for strengthening attachments that already exist between parts, and decouplers are for making temporary attachments.

 

[Alshain]

That's what I thought too except he said they disappeared, which wouldn't happen if you didn't decouple.  Anyway, we just need him to post a picture.

EDIT: Just occurred to me, maybe he thinks the Struts are cables, like the REAL sky crane.  OP, if that is what you think, that's not the case here.  Sky cranes in KSP don't have cables you just have to get close to the ground and decouple and let it fall a few feet.

Edited April 14, 2017 by Alshain

[VirtualBrain]

Yes I want to make a skycrane, but I just have 1 problem, the struct sonnectors.

You can see all retros and their attachments with struct (below the reactions wheels) :

You can see the rover :

And the winches attachment :

My objective : detach winches without detach the struct connectors, to keep the retros attached to each other and allow them to take-off after detaching rover.

Currently, when I detach the rover, the structs disappear and the retros don't take-off, just spin before fall to the ground because they aren't equilibrated.

Edited April 14, 2017 by VirtualBrain
Problem with pictures

[Dman979]

@VirtualBrain We can't see the pictures. In order to have them appear, upload them to a third-party hosting site, such as Imgur, and copy the direct link to the photo. It should end in .png, .jpg, or something similar.

[VirtualBrain]

43 minutes ago, Dman979 said:

@VirtualBrain We can't see the pictures. In order to have them appear, upload them to a third-party hosting site, such as Imgur, and copy the direct link to the photo. It should end in .png, .jpg, or something similar.

I added pictures

[bewing]

The skycrane part of the design has no probe core. So it has no control. I do not think you need the struts, but without a probe core the skycrane will always crash after it is detached from the rover.

 

[Alshain]

@VirtualBrain Struts can not be your only attachment point between two segments of the craft.  Before you decouple, the rover itself is serving as the the primary attachment point between the four rocket assemblies.  After you decouple, that linkage is gone so the struts break.  It's simply not possible to keep struts between two objects that have no primary connection.  Struts are meant to strengthen the attachment, not serve as the only attachment.

To make matters worse, you can't simply join the assemblies together with something like a girder because that would violate the multiple connection points rule.  You can not create a circular chain of part connections, it has to be linear.

I'm sorry to say you will need a redesign and re-think the idea.  This is just one of the quirks of how KSP works.  Your best bet would be to create the entire skycrane and then simply attach the rover to the bottom from a single connection point.  Trying to connect it to 4 spots and maintain the skycrane as a craft is not going to work.

EDIT

Alternatively if you don't really care what happens to the crane, you could put 4 probe cores on each of the 4 rocket assemblies to maintain engine power.  Right before you drop the rover (really at the same time) ram the throttle up to full, hit the decouple before the rover is too far off the ground, and then the 4 parts will fly off and crash independently.

Edited April 14, 2017 by Alshain

[VirtualBrain]

2 hours ago, bewing said:

The skycrane part of the design has no probe core. So it has no control. I do not think you need the struts, but without a probe core the skycrane will always crash after it is detached from the rover.

 

When I detach the rover, the retros stay activated, so if they stay attached between each other, they will take-off because the mass will reduce without the rover.

I have to attach the retros because the winches of KAS aren't stable, so after some flight time all the ship begins to move by itself.

[bewing]

1 minute ago, VirtualBrain said:

When I detach the rover, the retros stay activated, so if they stay attached between each other, they will take-off because the mass will reduce without the rover.

I have to attach the retros because the winches of KAS aren't stable, so after some flight time all the ship begins to move by itself.

As I said above, struts only reinforce connections that already exist between parts. The retros at the back end of the rover are not connected to the retros at the front of the rover. If you want those two parts to remain attached to each other, you need to make a connection between them, with a real part. Not jut a strut. I also do not see any part other than a strut connecting the retros on the left side of the rover with the retros on the right side of the rover. So again, if you want those parts to remain connected after decoupling, you need to put an actual part to connect between them.

 

[VirtualBrain]

55 minutes ago, bewing said:

As I said above, struts only reinforce connections that already exist between parts. The retros at the back end of the rover are not connected to the retros at the front of the rover. If you want those two parts to remain attached to each other, you need to make a connection between them, with a real part. Not jut a strut. I also do not see any part other than a strut connecting the retros on the left side of the rover with the retros on the right side of the rover. So again, if you want those parts to remain connected after decoupling, you need to put an actual part to connect between them.

 

Ok so what can I use to connect the retros because I found just struct to connect two independents parts ?

Edited April 15, 2017 by VirtualBrain
Bad syntax

[Alshain]

2 hours ago, VirtualBrain said:

Ok so what can I use to connect the retros because I found just struct to connect two independents parts ?

You can't.  You can't have circular connections.

[Jarin]

You'd have to redesign it so that the crane is a single unit with its own framework, then have the rover attached by a decoupler or docking port in the middle, which you would unlink before lowering it on winches.

[bewing]

You can connect the left and right corners of the skycrane with girders. And then run one girder from the front to the back, for example.

[Alshain]

2 hours ago, bewing said:

You can connect the left and right corners of the skycrane with girders. And then run one girder from the front to the back, for example.

That wouldn't work.  It would require that the front to back girder make a connection to the front and the back by itself.  It's still a circular connection with the rover there.

[VirtualBrain]

And if I add a core probe on the retros system, that should be work ?

[Harry Rhodan]

13 minutes ago, VirtualBrain said:

And if I add a core probe on the retros system, that should be work ?

No. They would still detach into four separate parts. In this game you can branch parts from a common root part but you cannot merge the branches back together. In your case you branched off four separate engine parts and used struts like duct tape to tape them together. But you would need to actually use structural parts like girders and the like to connect them, which you can't because you can't merge branched parts in the VAB.

Your skycrane can only have one attachment point to your rover. You need to attach those four separate engine things to a common root part and then attach that root part to your rover. If you absolutely need multiple attachment points you'd have to manually attach them in orbit with a Kerbal using the KAS winches.

[VirtualBrain]

12 minutes ago, Harry Rhodan said:

No. They would still detach into four separate parts. In this game you can branch parts from a common root part but you cannot merge the branches back together. In your case you branched off four separate engine parts and used struts like duct tape to tape them together. But you would need to actually use structural parts like girders and the like to connect them, which you can't because you can't merge branched parts in the VAB.

Your skycrane can only have one attachment point to your rover. You need to attach those four separate engine things to a common root part and then attach that root part to your rover. If you absolutely need multiple attachment points you'd have to manually attach them in orbit with a Kerbal using the KAS winches.

Ok so I will rework my structure.

Thanks for your replies !