Why won't this mesh rotate? and why does the instance spawn ABOVE the forcefield?

I am creating a forcefield tool and i'm still tweaking all of the parts, but i'm stumped at a part. Whenever this mesh spawns, the object doesn't rotate continually like i want it to. Also, when the mesh spawns, it spawns above the Force Field instead of inside it, next to the humanoid like I want it too. I'm assuming that's a collision issue, but i still don't know how to fix it. Here is the code:

local tool = script.Parent

local health = false

x = math.random(25, 50)
y = math.random(25, 50)

a = 0

b = 0

local debounce = false

local character = game:GetService('Players').LocalPlayer
local player = character.Character or character.CharacterAdded:wait()

tool.Equipped:connect(function(mouse)
    mouse.KeyDown:connect(function(key)
        if key == "q" and debounce == false then
    debounce = true
    print("ForceField")
    local ForceField = Instance.new("Part", player)
    ForceField.BrickColor = BrickColor.new("Deep blue")
    ForceField.Transparency = 0.7
    ForceField.CanCollide = false
    ForceField.Anchored = true
    ForceField.Shape = Enum.PartType.Ball
    ForceField.Size = Vector3.new(25,25,25)
    ForceField.BottomSurface = Enum.SurfaceType.Smooth
    ForceField.TopSurface = Enum.SurfaceType.Smooth
    ForceField.Position = player.Torso.Position
    ForceField.Parent = game.Workspace

    ForceField.Touched:connect(function(hit)
        local humanoid = hit.Parent:findFirstChild("Humanoid")
        if not hit:IsDescendantOf(player) and health == false then
            health = true
            humanoid.Health = humanoid.Health -3
            print ("DEATH TO THE HEATHENS")
            health = false
        else
            print("Hi Me ;)")
        end
    end)
    tool.Equipped:connect(function(mouse)
    mouse.KeyDown:connect(function(key)
        if key == "q" and debounce == false then
    local explosion = Instance.new("Part", player)
    local m = Instance.new("SpecialMesh")
    m.Parent = explosion
    m.MeshType = "FileMesh"
    m.MeshId = "http://www.roblox.com/asset/?id=20329976"
    m.TextureId = "http://www.roblox.com/asset?id=39251676"
    m.Scale = Vector3.new(8,8,8)
    explosion.Size = Vector3.new(8,8,8)
    explosion.Anchored = true
    explosion.CanCollide = false
    explosion.Transparency = 0
    repeat
        explosion.Rotation = Vector3.new(0,a,0)
        wait(.1)
        a = a+3
    until
    b == 0
    explosion.Position = player.Torso.Position
    explosion.Parent = game.Workspace
    wait(2)
    explosion:remove()

end
end)
end)
    wait(2)
    ForceField:remove()
    debounce = false
    end
end)
end)

it's quite a lot of code, but it's just spawning two different parts next to your character and damages anyone else that touches it, lol. Thanks in advance!