Rotating an object that over time starts speeding up? [Solved]

I'm scripting a fan that lets the fan blades rotate around repeatedly at a specified pace. My problem is that the fan blades start to speed up over time.

blades = script.Parent:GetChildren()
spinSpeed = 0.005
mathStart = 0 --angle start?
mathSpinRate = 0.005

while true do
    for _,v in pairs(blades) do
        if v.Name == "Union" then
                v.CFrame = v.CFrame * CFrame.Angles(0,math.rad(mathSpinRate),0)
                mathStart = mathStart+mathSpinRate
        end
    end
    wait(spinSpeed)
end