Undocking a ship in a cargo hold: why is it pulled out upside down

[gilflo]

Hi

I built a giant cargo SSTO and set inside the hold a ship docked with 2 clamp o tron.

I built the ship, set its docking port on COG, let's say it's the male, then I took the female Clamp o tron, reversed it and it fitted perfectly the male docking port. I took a Girder adapter, put it on the reversed docking port designed it as being the root part. Then I set the ship in my subassemblies section

Here you can see the ship, coming from subassemblies section and stuck by its root part on another Girder adapter and you can see the settings of the 2 docking ports, that are set to minimum.

Then i set this ship in a hold, the girder adapter fitting another Girder adapter in the hold of the cargo and you see it here.

My question is:

The cargo being stable in orbit, all yaw, roll and pitch indicators in neutral position, on Retrograde or prograde or whatever, the ship being held by the docking port on its COG, Why, when I decouple the node for undocking, is my ship pulled out going upside down on pitch axe or rolling also upside down on roll axe, even with the ejection force set to 0???

question 2: the docking ports setting seems self explanatory: do you have 2 set the settings on both ?

 

[Tex_NL]

Do you have MechJebs SmartASS enabled at the moment of release?
It's possible some settings are inherited by the decoupled craft causing it to flip and/or roll in an attempt to conform to SmartASS.

[pincushionman]

We'll need a picture of the un-coupled ship to know for sure, but it sounds like the payload-side port has been rotated 180 degrees (as in you rotated it "forward" twice to get it to point the right way) and you're using it as the control point (but the axis is in the correct direction).

On the Clamp-O-Tron there is a line on one side of the face which indicates "down" in the docking port's frame of reference. If this line is on the forward side of the port (the line is closer to the cockpit), then when the "control from here" is on the docking port, the cockpit will see the control inputs as:

Port pitch up -> cockpit pitch up
Port yaw left -> cockpit roll left
Port roll left -> cockpit yaw right
Port translate up -> cockpit translate aft
Port translate left -> cockpit translate left
Port translate forward -> cockpit translate up

If, however, the line is on the aft side of the port (further from the cockpit), then the cockpit will see:

Port pitch up -> cockpit pitch down
Port yaw left -> cockpit roll right
Port roll left -> cockpit yaw right
Port translate up -> cockpit translate forward
Port translate left -> cockpit translate right
Port translate forward -> cockpit translate up

I've emphasized the directions that get "changed" in each case. Now, if the line is on one side or the other instead, it's even more catty-wumpus (I've done this). Does that sound like what's happening?

Oh, and there is no "male" or "female" for the stock docking ports - they need to face each other and it appears you've done that correctly, at least.

Edited December 26, 2016 by pincushionman

[gilflo]

Thank's for answers, I look at that tomorrow (here it's night) and i tell you, especially that line "down". Ok I know there's no male or female docking port, they are similar....

And Yes mechjeb smart ASS is enabled at the release...I'll try with ASS of

Thank you

[Draalo]

That has often annoyed me too.

Click the dockingport attached to your Cargovessel and choose "controll from here." You ll notice that the whole ship is reorientating. Because the port is rotated by 180°.

 

When undocking, the transporter uses the dockingport as controllpoint, the cargo uses its port as new controlpoint - which is rotated, and that cause the 180° flip.

 

To avoid that, allways set the SAS to hold position when undocking. MechJeb SmartASS has nothing to do with it.

[gilflo]

@Draalo

Thank you.

You got the right answer. 

1/ Same "Control from here for both vessel

2/ Mechjeb smart ASS of if in use

3/ Just stabilize vessel in a position, prograde or whatever

4/ SAS on hold position (Keybinding F)

5/ decouple node

I tried a redocking in this very narrow hold for the AESV and it worked perfectly provided i set the AESV in the same position as when it was on dock: cockpit in the same direction than the main cockpit Vessel.

Thank's again guys!!