Ma Lin thought they were suitable for the rotating contraption used in a lathe.
Then fix the metal block onto a wooden frame and lock it in place with a wedge.
Next, use a bowstring to quickly drive this spindle into continuous rotation.
Then you can attach a piece of wood to the spindle to process it into a cylinder.
How do you secure the wood onto this spindle?
Place a fixed pointy iron rod opposite the spindle.
The spindle and iron rod align to form a straight line.
Then clamp the wood between the spindle and the iron rod.
The head of the spindle is fixed inside the wood, driving the wood to rotate.
The head of the pointy iron rod inserts into the wood but doesn't rotate with it.
How do you adjust the position of this pointy iron rod?
Straighten the line to adjust.
How do you fix it after adjusting?
Ma Lin thought using a wedge and then pouring molten iron might work as a fixing method.
When he actually made it, he failed many times.
