It is impossible to machine a cone at the end of a hollow tube. But if the need arises, then usually a knob is made from a solid blank and then welded. However, there is another solution, and a very unusual one. On a lathe, in one step you can not only plug a pipe, but also make a cone at its end.
What you will need:
- Lathe;
- spark plug;
- cutter.
The process of forming a cone on a pipe
The pipe blank must be clamped in a lathe.
Then, instead of a cutter, a spark plug is installed in it with the contact cut off close to the insulator.
After this, you need to make a groove in the end of the tube with a spark plug insulator. The friction will cause the edge to heat up and shrink.
The same steps are performed as for conventional sharpening of a solid workpiece to a cone. Thus, the tube is deformed into a cone.
Finally, it will be possible to install a real cutter and slightly correct the part.
The method is very simple, especially if the lathe has sufficient power.
