Hi Horia, running a moonlite 2", with a 5.5 lb load. When scope is at zenith, there is no slip and has been adjust to lay on the safe side of things.
Great observation though, as I have had it slip on me in the past. The give away were the graphs moving hundred of steps inwards, with little to no temperature change. By the end of the night the focuser thought it was at 0 when it racked halfway out.
Anyways mechanically, everything is seemingly peachy. 