Splitting a part into two for tree cutting

[titanpicha]

Hello, I’m attempting to make a tree cutting system but I’m having trouble splitting a part of a tree into two pieces at proper positions.

Below is the script and screenshots of the issue:

The size of both parts added together equal the size of the original part, so it appears as if the CFrames are the main issue but I’m having trouble finding a solution. I asked a similar question earlier today but my solution ended up failing. Any help will be appreciated!

[enjoyer_roblox]

You can use subract async: BasePart | Documentation - Roblox Creator Hub

[titanpicha]

Did I use this correctly? The tree looks like this:

Here’s my code in case I did something wrong:

For extra information, I’m trying to make a tree cutting system that basically chops trees like lumber tycoon.