Welded Parts not moving

Hello, I have two parts welded together, but when I move the part in a script the other doesn’t move. how do I fix it?

Are they part of the same model? If so you should probably be able to use Model:SetPrimaryPartCFrame (roblox.com).
I’m not quite sure, but I think the welded parts might move if you update their CFrame instead of position. If you are tweening it the following is a really good tutorial:
Introduction to Tweening Models - Resources / Community Tutorials - DevForum | Roblox

They are not in a model
It’s a part Inside a part.

But i don’t know how to tween CFrame
Here is the tweening part

TweenSrv:Create(Part,TweenInfo.New(3),{Position = Vector3.New(23,10,-89)}):Play()

CFrames get a rep of being more complicated than they are, think of them as extended Vector3’s.

Creating a new CFrame with a position? Simply do

local cf = CFrame.new(Vector3.new(0, 1, 0))

The above is equivalent to changing position to said Vector3. Another reason to use CFrames is rotation becomes really easy. Somtimes. Want a part to look at another part?

local cf = CFrame.new(thisPart.Position, otherPart.Position)

Tweening CFrame is very similar to tweening position. Same goes for all values.
Anyways, here’s how to tween CFrame:

TweenSrv:Create(Part, TweenInfo.new(3), { CFrame = CFrame.new(Vector3.new(23, 10, -89) }):Play()
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But it tween the orientation, how can i prevent it

CFrames can be offset by Vector3’s.
In this case you have a specific position in mind, so you need to calculate the position change.

local positionDelta = target - currentPosition
TweenSrv:Create(Part, TweenInfo.new(3), { CFrame = Part.CFrame + positionDelta } )

The result of

Part.CFrame + positionDelta

will be your target position with the same rotation as you initially had.

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Uhh, Could You please explain more

is, there an easier way? btw, thanks for replying.

Well, not sure which part you want me to explain
positionDelta is simply the distance, as a Vector3, between the start and end position.

If its the CFrame you are unsure about, I’ll try to simplify it a bit.

Imagine a CFrame as a dual-Vector3d. One describing position, another orientation.
Lets pretend the following is your Part’s current CFrame.

CFrame == (Vector3.new(0, 0, 0), Vector3.new(0, 0, 10)

As I mentioned earlier you can add Vector3’s to CFrames. Lets say we want to move our part to the position (10, 10, 10) and keep our rotation.

newCFrame = CFrame + Vector3.new(10, 10, 10)
newCFrame == (Vector3.new(10, 10, 10), Vector3.new(0, 0, 10))

As you can see, the new CFrame describes a new position with the same orientation. The reason we need to calculate positionDelta will become apparent when we try another coordinate. Lets say your Part is currently at (-10, 2, 3).

CFrame == Vector3.new(-10, 2, 3)
newCFrame = CFrame + Vector3.new(10, 10, 10)
newCFrame == (Vector3.new(0, 12, 13), Vector3.new(0, 0, 10))

As you can see, that didn’t really go as planned. We wanted it to end at (10, 10, 10).
What we are doing, basically, can be simplified to following math equation:

new = current + change
-- Since we are after the change we simply subtract current from new
new - current = change
-- The above statement is the same as the following
change = new - current

I hope this made sense. If not, just ask!

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I Understand(Your explanation was great), But I am tweening a LOT of parts, Is there any easier way, sorry to bother you.

No worries, I am here because I want to help!

Are those parts you are moving welded together? If you tween the CFrame of one of the welded parts all of them should move. (I think.)

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