How do I stop a "touch" function after being touched?

Hey there! You can add debounces, for more info on debounces click this link below;

http://wiki.roblox.com/?title=Debounce

Now I will help you edit your script;

model = script.Parent 
backup = model:clone()
local Cloning = false -- This is our debounce variable 

model.Touched:connect(function(part) -- When you have a variable with script.Parent just say the model
    if not Cloning then --If cloning is false then 
    Cloning = true --Set Cloning to true
        while true do
           wait(part)


            model:remove()

            wait(math.random(7,23))

            model = backup
            model.Parent = game.Workspace
            model:makeJoints()
        if Cloning then return end -- If cloning is true then return and end the script
    end
    end
end)

This script SHOULD function only once. If you want this function to function again then simply add a wait() and set Cloning back to false.

If helped in anyway please Upvote and Accept Answer

The reason your code keeps repeating is because of your while loop on line 7. Remove that if you don't want the model to continually regen.

To stop the Touched event's signal, you can use the Disconnect function of the Touched event's RBXScriptConnection.

Usage;

local model = script.Parent
local backup = model:clone()
local TouchedConnection
--^Predefine a connection var so we can access it inside the event

TouchedConnection = script.Parent.Touched:connect(function(part)
    model:Destroy() --Remove is deprecated!
    wait(math.random(7,23))
    model = backup
    backup = model:Clone() --reset the backup var so it can be used again
    model.Parent = game.Workspace
    model:makeJoints()
    TouchedConnection:Disconnect() --Disconnect signal
end)

Alternative methods to stopping the Touched event's signal would be:

• 1) Destroying the script: script:Destroy()

• 2) Adding a debounce