I’m making a Mig-21 for fun and I’m working on the nose gear, the design itself is fine, but I can’t get it to work just right. As soon as I run the game, the nose drops all the way to the limits and jumps around.
The current setup is pretty close to an Oleo strut, with the central spring and torque arms. I don’t know suspension very well, so I just tossed in some torsion springs for the arms, and used a normal spring for the chamber.
I know a bit about constraints but not enough to probably guide you to completion or solution… i guess my first question is why you chose to go with prismatic constraint rather than the popular cylindrical plus spring? The cylindrical will allow you to slide on an axis plus rotate on another… the prismatic will only allow sliding on an axis so its a rigid constraint. I saw you want the wheel to rotate, thats why i ask.
Second, have you applied enough force to the springs to hold the weight of the model? Unless your model is massless, this will probably be something that needs resolving. Making your model massless is actually a good way to check if you need to apply force to constraints or springs… sometimes if it doesnt affect your vehicle, just make it massless and its one less force to deal with… but then it doesnt move realistically so its ur call.
But in a nutshell if its dropping and getting jittery then i would guess your springs dont have enough force. Read the API on springs specifically the header Calculating SpringConstraint Force:
But if its too much, just trial and error with some high numbers until it works (thats why the massless “check” lets u even see if its the real issue to begin with).
I tried out the cylindrical constraint and it worked for a second before collapsing, even with massless on. I set the stiffness to infinite to see if that would do anything but no luck. I thought for a second that the torsion springs were messing stuff up but they seem to keep the arms in place so I think I gotta keep those.
Generally you shouldn’t be doing mechanisms this small. Roblox physics engine is really bad at handling complex mechanisms, and even if you managed to tune every constraint in your mechanism properly, it would probably glitch off easily.
