Monotower Crane
Built by Brian Leach in June 2020 for the Never Used Parts Secretary’s Challenge
I have never used the Meccano ball. However it is possible to make a small ball race with them. So there are two wheel flanges and the balls are held to the outer edge by 2” pulleys and wheel discs at the centre. Based on model 4.2 in the 1970s manual. The ball race makes it very stable.