by Marcelo Jost
I have recently acquired a copy of The Shop Wisdom of Rudy Kouhoupt, Volume Three. Despite the richness of Rudy’s projects and ideas, what really caught my eye was a chapter titled “Using the Diamond Tool holder,” also known as a tangential tool holder. I had already seen the tool holder advertised in the magazine, but never really paid any attention to it, mostly due to a lack of understanding of how the tool and tool holder work together. Rudy clearly explained how the tool holder was used, how the bit was sharpened, and some other advantages, such as, for instance, the fact that you can make both facing and turning operations without moving the tool holder or changing the bit. Rudy also stated that the tangential toolholder could be used in a Sherline lathe, which is a main concern for me since it is the only lathe I have. Rudy finally stated that he was very satisfied with the tool holder, as can be seen everywhere else in the book by means of several photos showing the toolholder in use over and over again.
In fact, Rudy seemed to be so fond of his tangential tool holder that he convinced me to give it a try. (I must confess that the laziness of being able to leave the toolholder in one position while turning and facing is also very appealing!) However, at the same time I decided to give the toolholder a try, some thoughts crossed my mind:
- A dreadful thought: the advertised tool holder is quite out of my budget and I would have some problems explaining to my wife that I need another tool holder that “holds those small metal pieces just like the others you already have.”
- A worrisome thought: something I dislike about the advertised tool holder is that it is clamped in the Sherline tool post as if it was a tool bit. This leaves the tangential tool bit hanging almost an inch away from the lathe tool post. The bottom line (in my mind, anyway) is that you put too much lever strain in the cross-slide of a small lathe such as the Sherline.
- A bothersome thought: this is also a personal complaint about almost every tool post I have seen so far, but the final assemblage of the tangential tool holder in the Sherline tool post looks quite massive over the cross-slide, and the fact that the workpiece sometimes looks hidden behind the tool post bothers me.
The simple answer to all those problems was to build my own tangential tool holder, and this is the project I want to share with you now.
“Tangential Toolholder for a Sherline Lathe” appears in the upcoming January/February 2009 issue of The Home Shop Machinist.