New Turntable DesignWritten by TJ on July 19th, 2012
The difficulty with large turntables made of LEGO parts is making them strong enough and stiff enough to withstand the large loads and moments that get applied to them. I’ve made many turntables through the years and I’ve noticed a lot of them have suffered from wanting to pry apart under load.
A solution to this is to make a sandwich of roller bearings; basically a self-contained stack of rings separated by bearings. It’s difficult to put into words, so hopefully this diagram will help:
This is the design currently used in my latest crane. The model is meant to be a tower crane with a luffing boom, but it is also a test bed for some new ideas that I’ve had.
I built the turntable for this years ago. I intended to use it to make a hammerhead style tower crane, but decided later to turn it into a slightly different style with a luffing boom.
The turntable uses the same roller bearing ring as used on my 4×4 offroad crane.