Help with CylindricalConstraint and Springs for my Car!

[DaReal_Loathsome (Loathsome)]

I wasn’t sure if this goes in Scripting or Building support, but since it’s mostly a Physics based problem I think building is probably the one.

I have been working on the basics of car physics for the past two days and have hit nothing but roadblock after roadblock and I need help,

Here is my car:

In a previous iteration of the Vehicle the physics would spaz out so bad it would fly out under the map as soon as the player touches it, After continuing to tinker with it It no longer messes out as much but the suspension does not work at all, and instead the CylindricalConstraint just stretch out to the maximum possible suspension without any give for the physics, Not only that but half the time the tires do not even roll.

You can see that here: https://www.youtube.com/watch?v=TbFc6yYD-x8

What I have tried:
1 Changing friction and other physics properties of the wheels and other parts of the car.
2 Changing the properties of the springs, CylindricalConstraints, etc.
3 Moving/Redoing Attachments for the springs and CylindricalConstraints.
4 Redoing the wheels and Body of the vehicle.
5 Disabling suspension and only focusing on CylindricalConstraints.
6 Starting from Scratch again and again.

For example in an older model of the vehicle the tire meshes would act as the collision for the tires themselves, the suspension would work fine in this iteration but since the mesh was not simulated as a perfect circle the driving would be jittery, after that I used invisible cylinders to act as collision for the wheels, that fixed the jitteryness (mostly), but then the suspension broke again for no reason other then the part was no longer a mesh.

Here are screenshots of everything in the car including properties and a few of the scripts though I don’t think they matter here, I’m adding them just in case:

To make the car I used this tutorial:

Cars With Suspension - Roblox Scripting Tutorial

Though as of right now the vehicle has been changed so much over the course of this endeavor that is does not share many similarities with the one in the video

If you want to test out the vehicle for yourself, and see if you can fix things here is the place:
CarTestPlace.rbxl (316.2 KB)

Thank you for your help.

[Scottifly]

I can have a look after work, but here’s a few questions:

• what’s the density/mass of the car. Too high and it’s going to squash the springs, too low and the springs and joints tend to take over and glitch.
• you have the Damping of the spring set to 200 which means it’s going to instantly try to get to 3.2 studs. I believe most of the cars I have the Damping is between 10 and 20. Of course you’ll have to tune it to your vehicle mass and the wheels Density.
• I tend to make the Density of wheels something like 2 so they don’t get instantly affected by springs which allows for a smoother movement.
• If the tires aren’t rolling there’s a JoinSurfaces tool on the top left of the toolbar that Welds parts that are in contact with each other. I had someone post about his cars not moving a couple of days ago and I could see from his picture he had the checkbox on and the wheels were welding to the baseplate.

[DaReal_Loathsome (Loathsome)]

Thank you for the response,

I have tried changing the mass of the car and had zero change each time.

The 200 damping has only been a part of the most recent iteration, at lower damping there was no change but I will change it back.

And as far as the tires, it rolls 50% of the time, it’s not welded to anything it just seems like some wheels are gliding on ice with others move properly, (To see what I mean here is a video https://www.youtube.com/watch?v=TbFc6yYD-x8), You can see the back right wheel not turning, while other times it turns normally and other wheels don’t.

[Scottifly]

Do you have parts colliding with each other?
In your Studio Physics settings there’s one named AreContactsShow (or something like that). Click it on and you will see red spheres where items collide with each other. It’s great for troubleshooting moving assemblies.

[DaReal_Loathsome (Loathsome)]

Yup, did that too. Everything has its own Collision-group so that part is not a problem. this is why I’m so frustrated with this, I did everything right.

If you can, I think the best way to help would be to tinker with it on your own.

[DaReal_Loathsome (Loathsome)]

Never-mind, I got it! I went back through and made sure everything was up to spec, and using the examples you gave me turns out I got a few things wrong, The biggest one being that I did forget to set the wheels collisiongroup when I switched out the wheels, Thank you for the help.