How to get all parts to move (rotate) with all other parts in same model

[PastelRavenGirl (PastelRaven)]

Currently I have a cylinder that spins with other parts attached in same model.
Model >
Model
Part>
Script

local TweenService = game:GetService('TweenService')
local part = script.Parent.Part
local tweenInfo = TweenInfo.new(
	3, 
	Enum.EasingStyle.Linear,
	Enum.EasingDirection.In, 
	-1, 
	false, 
	0 
)

local spinTween = TweenService:Create(part, tweenInfo, {Orientation = part.Orientation + Vector3.new(360, 0, 0)})
spinTween:Play()

How can I get all parts in Model to rotate with the Part moving? If you have a model with a lot of parts, can you get away without welding every single one of them?

[RMofSBI]

Maybe you can try to tween the entire model instead… here is a tutorial:

Introduction to Tweening Models

Note (06/30/2021): Due to the release of the new pivot APIs and the thankful deprecation of SetPrimaryPartCFrame, the legacy method of CFraming is now also appropriate and you do not necessarily need to use this welding method. Do note that the pivot CFrame is different from the PrimaryPart CFrame though, so you will have to account for that when writing your proxy objects. Contents Introduction Understanding Tweening Concept of Tweening Models Rigging Your Model 4.1. Setting Up the Root 4…