"loose" pistons?

[lordfadooboo]

im trying to make a ramp like the ones in starwars on shuttles or the falcon where the force comes from 2 pistons at the tip of the ramp instead of force coming from the hinges. to acheive this, the ramp itself needs some stretchability in the form af a "loose" piston. one that can get pushed and pulled by other forces without exerting any force itself. ive tried setting velocity to 0, setting force as low as possible, and just turning that piston off but it seems locked in place. i made sure the piston wasnt accidentally merged to itself.

does anyone have any ideas? im aware this is the complicated way of doing something simple. it just looks cooler. but if i have to abandon that idea then it is what it is.

[CaveDweller]

I encourage you to listen to the more experienced players on this issue, though my initial thought is having the pistons attached to hinges and rotors. Admittedly I have no idea if this would even work (ramp-hinge-piston-possibly another hinge-rotor)

[carl.wear]

Hinge, piston, piston, hinge.

Turn the hinges off and make sure they are not locked. The 2 pistons are so you have some reach to open the ramp. Also with the hinges off, the pistons have a bit of movement where they connect inside the ship and to the ramp.

Kind of loosely like doing a trailer hitch where you have 2 hinges and a rotor but they are turned off to allow for the full movement so hopefully nothing snaps off.

[TheHellKat]

I know the issue you are having, I've done that exact build a few times myself.

Mostly it ended in boom.

My most successful attempt had a piston on the ramp itself with timer blocks set up to extend/retract the ramp length to allow a smoother motion.

It took me quite a while to get the timing right without detonating the ramp.

[lordfadooboo]

Originally posted by carl.wear:

Hinge, piston, piston, hinge.

Turn the hinges off and make sure they are not locked. The 2 pistons are so you have some reach to open the ramp. Also with the hinges off, the pistons have a bit of movement where they connect inside the ship and to the ramp.

Kind of loosely like doing a trailer hitch where you have 2 hinges and a rotor but they are turned off to allow for the full movement so hopefully nothing snaps off.

is that for the main up and down pistons or do you mean on the ramp itself? currently the up and down is piston piston hinge, and the ramp is hinge piston. and what would you say about shared inertia tensors? ive been trying to play with them on and off, this side on but that side off and so on.

[carl.wear]

Originally posted by lordfadooboo:

Originally posted by carl.wear:

Hinge, piston, piston, hinge.

Turn the hinges off and make sure they are not locked. The 2 pistons are so you have some reach to open the ramp. Also with the hinges off, the pistons have a bit of movement where they connect inside the ship and to the ramp.

Kind of loosely like doing a trailer hitch where you have 2 hinges and a rotor but they are turned off to allow for the full movement so hopefully nothing snaps off.

is that for the main up and down pistons or do you mean on the ramp itself? currently the up and down is piston piston hinge, and the ramp is hinge piston. and what would you say about shared inertia tensors? ive been trying to play with them on and off, this side on but that side off and so on.

Now I am wondering about your ramp. Is it a ramp or a lift?

If your ramp is just pistons to lift up a platform then don't need hinges.

But

If your ramp is attached at one end to a hinge so it raises and lowers on a hinge but you want to use pistons to lower it, then you need a hinge on each end of the piston due to the ramp angle moving.
Example, The ramp when raised is pointing vertically, Ramp lowered is horizontal. A piston, trying to open the ramp will break as it cannot flex as its fixed to its attachment points and as the ramp angle changes, something will break. --- SO, Having a hinge on each end of the piston, allows the piston to move at its connection points as the ramp lowers.

Shared inertia tensors, only works in experimental mode. I am not sure exactly what it does but in some situations people have had problems when using it.

Got a screenshot of what you are trying to do, that will help me better understand if what I am explaining will even work in the solution you are after.

[ShadedMJ]

I suggest keeping an eye out during game loading. I had a bunch of ships with pistons and rotors, and on game load the ships with landing gear active were skidding across a lakebed colliding with each other and causing chaos.

[lordfadooboo]

Originally posted by carl.wear:

Originally posted by lordfadooboo:

is that for the main up and down pistons or do you mean on the ramp itself? currently the up and down is piston piston hinge, and the ramp is hinge piston. and what would you say about shared inertia tensors? ive been trying to play with them on and off, this side on but that side off and so on.

Now I am wondering about your ramp. Is it a ramp or a lift?

If your ramp is just pistons to lift up a platform then don't need hinges.

But

If your ramp is attached at one end to a hinge so it raises and lowers on a hinge but you want to use pistons to lower it, then you need a hinge on each end of the piston due to the ramp angle moving.
Example, The ramp when raised is pointing vertically, Ramp lowered is horizontal. A piston, trying to open the ramp will break as it cannot flex as its fixed to its attachment points and as the ramp angle changes, something will break. --- SO, Having a hinge on each end of the piston, allows the piston to move at its connection points as the ramp lowers.

Shared inertia tensors, only works in experimental mode. I am not sure exactly what it does but in some situations people have had problems when using it.

Got a screenshot of what you are trying to do, that will help me better understand if what I am explaining will even work in the solution you are after.

ok so heres a screenshot https://steamcommunity.com/profiles/76561198128366710/screenshots/
the idea was that this piston on the ramp and the hinges on the main lowering pistons would make it so that as the ramp lowered, instead of the main pistons bending, the ramp would just get pulled out a little to accomodate the new length required. but i cant seem to get the ramp pistons to extend at all unless i tell them to on their own which isnt what i want. im trying to get them to accept outside force and get pushed and pulled by the main pistons without resisting.

[carl.wear]

I improved my initial test by raising the pistons up a row.

https://steamcommunity.com/sharedfiles/filedetails/?id=3357479734

https://steamcommunity.com/sharedfiles/filedetails/?id=3357479627

https://steamcommunity.com/sharedfiles/filedetails/?id=3357479517

Hope it helps.