How to play animations on fake arms for FPS games

I am working on a gun system. I found this tutorial on how to make a first person view for the guns and I found it pretty useful.

The system is very interesting. In short, it creates fake arms holding a copy of the actual gun model that make the player feels that he is holding the gun. This “fake arms effect” is pretty popular and used in lot of FPS games.

The code is very complete and it has a nice and smooth aiming, that make the gun center the screen when you aim, even without playing any animation! (this part is important)

It uses a spring module and change values related to CFrame to achieve this effect without animations, positioning the arms and the weapon on specific positions.

I’m trying to make a “safety” mode that will lower the player arms. Like this:
image

Actually, I already managed to do that for the actual character model. I used CFrame rotation for the upper arms, but it could be also an animation.

The problem is: I want to make the same effect on the “fake arms”, so the player will see their arms lowered in first person.

However, for the fake arms, changing the CFrame to rotate them didn’t work.

The fake arm’s gun model is not attached to the RightHand (like the actual gun). Instead, it is attached to the viewModel’s Head using a Motor6D.
image

So, with the gun attached to the Head, rotating the arms have no effect on it.

The code also has a part that keeps updating the arms position on every RenderStepped to keep it smooth for the ilusion in first person.

I will not paste the entire script here because it is a bit long. Instead, you can check on how the system works by editing the Open Source Game provided by the post author on the tutorial previously mentioned.

My question is: how can I achieve this “lowered arms” effect for the fake arms in first person?

Edit: Aditionally, how can I play any type of animations on the fake arms? Like reloading animations also? I changed the post title to best describe what I want to achieve.