Minimal force on VectorForce is causing a huge upforce

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#1

Im trying to do a hoverboard, but applying just 1 to the force is causing the hoverboard to fly up super fast. All parts on the Rocketboard are Massless, but the RootPart isn’t and has a high density. This is to make sure that ALL boards have the exact same physics (regardless of shape/size/etc)

I also make the player massless and have low density to make for the same reason as above (so different players don’t get different results due to what they’re wearing adding different amounts of density/etc)

local Player = game.Players.LocalPlayer

game.UserInputService.InputBegan:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.E then
		local HumanoidRootPart = Player.Character:FindFirstChild("HumanoidRootPart")
		if not HumanoidRootPart then
			return
		end

		local RocketboardModel = game.ReplicatedStorage:FindFirstChild("BasicRocketboard")
		if not RocketboardModel then
			return
		end

		local Params2 = RaycastParams.new()
		Params2.RespectCanCollide = true
		Params2.FilterType = Enum.RaycastFilterType.Exclude
		Params2.FilterDescendantsInstances = { Player.Character }

		local RaycastDown = workspace:Raycast(HumanoidRootPart.Position, Vector3.new(0, -50, 0), Params2)
		if not RaycastDown or not RaycastDown.Instance then
			return
		end

		local RocketboardClone = RocketboardModel:Clone()
		RocketboardClone.Name = "Rocketboard"

		local Size = RocketboardClone:GetExtentsSize()

		-- Correct orientation using player's LookVector with a 180-degree adjustment
		local PlayerFacingDirection = HumanoidRootPart.CFrame.LookVector
		local SpawnPosition = RaycastDown.Position + Vector3.new(0, (Size.Y / 2) + 2.25, 0)

		-- Pivot the rocketboard to spawn position and rotate it to face player's direction (flipped 180 degrees)
		RocketboardClone:PivotTo(
			CFrame.new(SpawnPosition)
				* CFrame.Angles(0, math.atan2(PlayerFacingDirection.X, PlayerFacingDirection.Z) + math.pi, 0)
		)

		local HeightOffset = HumanoidRootPart.Size.Y / 2 + 0.5

		-- Adjust player's position above the Rocketboard
		HumanoidRootPart:PivotTo(
			CFrame.new(RocketboardClone.Collider.Position + Vector3.yAxis * HeightOffset)
				* RocketboardClone:GetPivot().Rotation
		)

		-- Set up welds and constraints
		RocketboardClone.PrimaryPart.CharacterWeld.Part1 = HumanoidRootPart

		RocketboardClone.PrimaryPart.AlignOrientation.CFrame = HumanoidRootPart.CFrame.Rotation

		RocketboardClone.PrimaryPart.AssemblyLinearVelocity = HumanoidRootPart.AssemblyLinearVelocity
		RocketboardClone.PrimaryPart.AssemblyAngularVelocity = HumanoidRootPart.AssemblyAngularVelocity

		RocketboardClone.Parent = Player.Character

		-- Make the player massless
		for _, child in Player.Character:GetDescendants() do
			if not child:IsA("BasePart") then
				continue
			end

			if child == HumanoidRootPart then
				continue
			end

			child.Massless = true
		end

		HumanoidRootPart.CustomPhysicalProperties = PhysicalProperties.new(0.0001, 0, 0)
	end
end)
#2

Remember, Acceleration = Force / Mass so you might have set mass too low (as you can’t edit mass directly but have to edit size and density (dont know why roblox does it like that))
Maybe instead try and sum all the masses of the rocketboard and the player and then choose the intended acceleration from there (Find Force = Mass * Acceleration instead )
This might have issues with center of mass and whatnot but if you otherwise keep with the current setup of having only a few central parts you know are all centered at the same place this wont have any CoM issues

#3

wait what is the size of the rootpart of the rocketboard because currently it seems really small so despite the high density it has low mass

#4

RootPart is 1,1,1. I think I figured it out, I had to include Massless to thje Totalmass (for some reason) but jumping causes a constant upward momentum not returning back to earth

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