The old watchmaker's magnifying glass (in the picture on the left) has served me well for decades in my job and hobby. Recently, when I went to reach for it, I was surprised to see that the lens was lying next to the torn tube. I immediately discard the most obvious idea of using glue: this is a good opportunity to try out the old technique of sprinkling on a real example!
This technique requires precision because it makes use of the elasticity of wood as a material. The diameter of the tube's recess is slightly smaller than the diameter of the lens and is turned behind at the point where the lens should find its place. The lens is then pressed in with “gentle force”. At first you will notice a clear resistance that the wood offers in the narrowest part. Once this has been overcome - thanks to the elasticity of the wood - the lens should "snap" into its intended position as if by itself.
The injection technology is probably no longer considered contemporary for everyday objects. (These days, even a watchmaker's loupe is made of cheap plastic!) Nevertheless, it would be a shame if this old working technique were completely forgotten. It's great when (hobby) woodturners looking for interesting challenges can return to such old techniques and find new applications for them!
The mouse trapped in the cheese - based on an idea by
David Springett - is a particularly successful example of this!