Help changing size of meshpart but it brakes the welding its also welded to another meshpart?

--// Edited for code block. In the future, please enclose all code within your question in a code block by inserting it within two sets of tildes (~).
local saberHight = 0.2

while wait() do
	if saberLight == true then
		if saberHight < 3.616 then
			saberHight = saberHight + 0.1
		elseif saberHight > 3.616 then
			saberHight = 3.616
		end
	else
		if saberHight > 0 then
			saberHight = saberHight - 0.1
		elseif saberHight < 0 then
			saberHight = 0
		end
	end
	saber.Size = Vector3.new(0.2, saberHight, 0.2)
end