Mini-Lathe Beginners

Boring on a mini-lathe

Put simply, boring is the art of taking a small hole and making it bigger.

Often when making a part I need to make a tube with in inner diameter of perhaps 1 inch. I do not have a 1 inch wide drill bit! To make such a shape on a mini-lathe we have to use a method known as boring. The picture below shows my mini-lathe setup for a boring job.

Boring is rather well named... its, urm, quite boring. Essentially you have to drill a hole into the job with your biggest drill bit - I use a 13mm drill bit. Then you have to mount the boring tool on the tool post so that it is parallel to the ways. The you use the tools to slowly increase the inside diameter of the job to the size you require. The most you can take off in each pass is about 0.5mm - so it can take a long time to make a 2 inch bore hole!

When starting it is quite difficult to fit the boring tool into the 13mm hole. You have to experiment with moving the height of the tool around so that it fits into the narrow hole. Once you have taken off a few mmm it becomes much easier.

If your job is very long, then using the power feed to do the work is recommended. This involves setting up the change gears with the very small and very large gear options so that the carriage moves slowly along the work. Lifesaver!

When boring on the mini-lathe I strongly recommend the use of a Glanze boring bar.