Is it possible to tween parts with cframe without moving the char if are welds inside?

local uis = game:GetService("UserInputService")
local plr = game.Players.LocalPlayer
local cFrameModule = require(game.ReplicatedStorage.CFrameModule)
local easeFilters = require(game.ReplicatedStorage.EaseFilters)
--Dosen't worked well :/
uis.InputBegan:Connect(function(input)
    if input.KeyCode == Enum.KeyCode.R then

local part = script.Parent.Slide.Weld

cFrameModule.tweenPartCFrame(part,0,nil,part.CFrame * CFrame.new(0,0,-1),true,nil)
wait(2)
local part = script.Parent.Slide.Weld.

cFrameModule.tweenPartCFrame(part,0,nil,part * CFrame.new(0,0,1),true,nil)
    end
end)

-- The gun model has welds so is there any way to tween cframes without roblox's crappy tweenservice? Sorry for my bad english :/