How would I move a model using TweenService?

local StartCF = DoorModel.PrimaryPart.CFrame

local function OpenGate()
    for i = 1, 50 do
        DoorModel:SetPrimaryPartCFrame(StartCF:lerp(StartCF * CFrame.Angles(-math.rad(0),-30,0), i*0.0225))
        wait()
    end
end

local function CloseGate()
    local NewCF = DoorModel.PrimaryPart.CFrame
    for i = 1, 50 do
        DoorModel:SetPrimaryPartCFrame(NewCF:lerp(StartCF, i*0.02))
        wait()
    end
end

This is the code in which I am already using to move my model, but it looks very "jumpy" due to the fact it uses CFrame and not TweenService.

I have tried to manipulate the above code to work using TweenService, but I can't seem to achieve it.