Object expected, got string,what?[Not Fixed]

I'm trying to make this snake animation thing with Mortor6D ,but I got a error in the output,what does it mean and how could I fix it?

If you can give me tips on how to make this script organized it will be appreciated and if you manged it fix please show how.

The error in the output is:

Workspace.Model.Script:12: bad argument #3 to 'Part1' (Object expected, got string)

Script 'Workspace.Model.Script', Line 12

Stack End

The script:

--~-----------Vairbles---------------~--
local Model = script.Parent
---------------------------------------------   
    for Number,Part in pairs (Model:GetChildren()) do
--------------More Vairbles----------------
local PreviousPart = math.floor(Number - 1)
local PreviousPartName = "Part"..PreviousPart
local Motor = Instance.new("Motor6D",Part)
-------------------------------------------
	print(PreviousPartName)
    Motor.Part0 = Part
	Motor.Part1 = PreviousPartName
    print(Motor.Part0)
	Motor.DesiredAngle = -Number
    end

I have the model setup like this:

Model Picture

In line 12 you have Motor.Part1 = PreviousPartName Because of the Motor.Part1 it is looking for an object, and is registering the other section of that line: PreviousPartName as a string. Try changing it to

--~-----------Vairbles---------------~--
local Model = script.Parent
local Motor = Instance.new("Motor6D",Model)
---------------------------------------------   
    for Number,Part in pairs (Model:GetChildren()) do
--------------More Vairbles----------------
local PreviousPart = math.floor(Number - 1)
local PreviousPartName = "Part"..PreviousPart
-------------------------------------------
    print(PreviousPartName)
    Motor.Part0 = Part
    Motor.Part1 = PreviousPartName.Part
    print(Motor.Part0)
    end

I am not entirely sure if that will work, as I am fairly new myself, but it seems like that is the issue it is having.