Can't find the sweet spot for spring suspension

Help and Feedback Scripting Support
#1

Hello I need some help with spring suspension, for some reason it just keeps shaking a lot, and it’s inefficient and doesn’t feel great on steering, it doesn’t work fine and when going straight it steers for no reason.
Here are 2 videos.
I’ve tried to change ALL values, nothing gets me to what I want to achieve


#2

A lot of times, this might be an issue of either the vehicle having too little mass, or the wheels having too little mass while the chassis has too much mass. My guess is the first one for you.

Mass = Density * Volume

To increase mass, you either need to increase density, or increase volume. You can increase density by setting the custom density property under a part’s custom physics properties. You can increase volume by simply resizing parts. Sometimes I have a hidden part at the center of mass that I adjust in size and density to get the mass I need.

2 Likes
#3

That’s helpful, how do I calculate density and volume?
Currently doing this for mass

                            local Mass = 0

						for i,v in pairs(Vehicle:GetDescendants()) do
							if (v:IsA("BasePart") or v:IsA("MeshPart")) then
								Physics:SetPartCollisionGroup(v,key)
								v.Anchored = false
								Mass += v:GetMass()
							end
						end

						Mass = Mass * workspace.Gravity
#4 
local Mass = 0

						for i,v in pairs(Vehicle:GetDescendants()) do
							if (v:IsA("BasePart") or v:IsA("MeshPart")) then
								Physics:SetPartCollisionGroup(v,key)
								v.Anchored = false
								local ThisMass = v:GetMass();
								local Density = v.CustomPhysicalProperties and v.CustomPhysicalProperties.Density or PhysicalProperties.new(v.Material).Density
								local ThisVolume = ThisMass / Density
								Mass += Density * ThisVolume
							end
						end

Something like this would work?

#5

Honestly I’d probably prefer to mess with the settings in Studio rather than via a script. I would try to fine-tune a single central part of the vehicle. It will just make your life a bit easier I think

#6

Well I do have a “MainPart” that adds weight, but how do I know when I have the perfect weight?
Because I would need to do thousands of tests otherwise :thinking:

#7

I don’t have a good answer for that, sorry! I’m sure there’s others that might know the more precise math to this, but that’s not my expertise. I just do some trial-and-error til something feels right.

#8

Do you just put random parts like in front/rear until you get that spot?

#9

Because I’m trying and get the same results


Let me show you the chassis setup, perhaps it’s that?

#10

@sleitnick Help me out if you can or check my chassis, I’ve been with this problem for a month and I’m not joking, I just kept skipping because I couldn’t find solution

#11

Well I just give up with this chassis

#12

It takes what it takes.
https://devforum.roblox.com/t/hiring-constraint-experienced-to-properly-adjust-my-suspension-100-usd/1349783/2

#13

Sorry to bump this, but you don’t need to pay anything for a simple issue that has been solved before.

Your other physics parts are too small compared to your wheels.
Edit: Previous solution.

The size needs to be considered or (this is just my assumption based on general physics knowledge,) the force calculations tend to get a bit out of wack.

#14

I put the size to the same of the wheel size, it still shakes a bit, how big does it has to be?

#15

Can you show me the properties of the constraints? Preferably all of them, if possible.

EDIT: Another issue may be your attachments not physically surfacing with their parent part (in the case of the “Axle” (part with hinge constraint and the spring, that is sitting inside the wheel.)

#16


Well know its way better, but that LITTLE shaking is a bit annoying.

#17

image
image1614×635 201 KB

#18

Hm. Alright, can you tell me the “Mass” property of all the Front Left suspension assembly parts? With labels please, as well as the Back Left? Can you also include the mass of the primary weight object?

(You can ignore sending the rear info if they are symmetric.)

Edit to reply: No problem, let me know if you need any further assistance.

#19

Well I consider this is sort of going tooo far
I think I will use weight parts too
I will put all to massless and use a center part so I can achieve the proper weight!

But from what sleitnick and you said, have helped a lot

And the shaking now it’s not annoying atleast, it’s not like I can’t handle it :grinning_face_with_smiling_eyes:

Thanks!