I am doing a welding script that welds a part to the player if they press a GUI but i don't know the command for sizing the block.
local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()
Mouse.Button1Down:connect(function()
wait(0.1)
local Sleeve = Instance.new("Part", workspace)
Sleeve.Size = Vector3.new(1.11, 0.92, 1.07) --need help here
local w = Instance.new("Weld", Sleeve)
w.Part0 = Player.Character.RightUpperArm
w.Part1 = Sleeve
end)

3 comments
You've done it correctly. What's the issue?
It wasn't showing up for some reason, and now theres a new problem everytime i do the script it automatically welds to the baseplate if i jump.
You need to set the C0 and C1 for your weld, so that the game knows how far away the parts need to stay from each other. I suggest you check out http://wiki.roblox.com/index.php?title=Weld as it is explained there.