Cross slides, also known as milling tables and xy cross tables, are an essential part of the rim lathe as it is currently conceived. Since creating my first prototype, I have actively searched for the best possible cross slide. This article is an overview of the results of my research.
One or Two?
Ever since I began designing rim lathes, I was always looking for a way to use a single cross slide instead of two. The downfall of every disign using one cross slide was the same: when you are cutting the inside of the rim, the tool is extended almost three inches from its anchor point on the tool holder. A single cross slide would require that, in addition to the tool extension, the tool holder would itself have to be extended. See Figure 1.
|
Figure 1. |
The blue box in the middle of the illustration represents the areas than need to be accessed by cutting tools. It is such a small area that it seems there must be a way to use one cross slide. As you can see from Figure 1. The tool holder is extended over three inches and the tool is extended an additional three inches. The force exerted during cutting will be a twisting motion that will cause the boring bar be deflected or, in the worst case, to dig into the work. Theoretically, if the tool holder base is very robust, this will not be a problem. I have not tested it yet. Prototype 3 is inteded to cut non ferrous metals. My intuition tells me that you might be able to get away with one cross slide for wood parts, but not for metal. |
 |
This is an interesting cross slide from the Grizzly catalog. It has an option for a motorized feed. This might work for the cross slide at the side of the lathe head, but it is not ideal for the cross slide in front of the lathe head. There is an extension at the end of the table that will make it hard to avoid running one cross slide into the other when using the slide in front of the lathe head. |
 |
I really like this cross slide. It has smooth action and excellent handles. I used it successfully on prototype 1, but only for the side cross slide. It has the same problem with the Grizzly slide shown above. It has a handle at the both ends of the table. It is therefore not suitable for the front slide. |
 |
This is the Phase II slide from Enco. Used for the front slide in Prototype 2 and for both side and front slides in Prototype 2. I also intend to use it in Prototype 3. Unfortunately, the handle assembly is not well designed. The handles do not rotate. It has really bad backlash (turning the handle with a delayed response before the table starts to move). These slides can be re-engineered to make them easier to use. Having said all that, I used them without modification for quite a while. |
