I think it will be safe to assume that there is no smoothness in the gear train. Perhaps there is when the thing is fresh from the factory, but for how long?
The thing is also powered by a 'wind up' elastic rubber band. How smooth will that be? How constant too?

Or in short: it's a cheapo Lomography product, and any positive expectation regarding the quality of the thing will very probably prove to be far too optimistic. Whatever we do, we must not mistake it for a serious tool.

It can still be a fun thing though. Were it not for the price...