Nix on the pulley. It doesn't replicate the issue at all. Pulleys are used to change the direction of the pull and it won't lock the beam and upper rope into a locked system. For example a rope lifting the weight and passing around a pulley produces the same tension in the rope on both sides of the pulley.

And before you shout "EUREKA! ! " it's not applicable to our spokes. Last I saw our wheels don't have pulleys on the spokes.... All joking aside our spokes are fixed in length so to replicate this in the model the upper string needs to be secured with a non slipping fit to the end of the beam. I was thinking that just a couple of wraps around the end of the beam would do it. The friction of the thread on the wood is all you need.

Besides if you did put a pulley on the end of the beam it would just let it fall down to the bucket until it jams on handle and THEN it would be back to a locked system and you can lift it and see the buildup as the angle lays over. But the bucket will tend to swivel from vertical if you do that.

If you're doing this on a small bucket and string or thread scale for ease of lifting then with the bucket on the table or floor just angle the arm down maybe 10 degrees and slip a few turns of thread around the end to lock it in place. Maybe a little notch in the end of the stick will let the final turn pass around the end and up without slipping down the length of the beam. Then when you lift just bring it up that little bit needed to reach level or near as the eye can see. That way you won't need any ropes to hold it up.