Mark Singer
07-13-2005, 1:36 AM
This was copied from David Marks website and explains that safety and accuracy can be improved by using aids and that you are not compomising one aspect in lieu of another....
"Jigs And Fixtures One way to look at them is that they are solutions to problem solving. Jigs can be defined as a portable device that guides the cutting tool, while a fixture is something that attaches to a machine and allows the stock to slide while being held firmly. As we explore the various examples of jigs and fixtures, it occurs to me that there is probably some cross over of definition. Either way, these devices, whether manufactured or shop built, are clearly of enormous benefit to the woodworker. For example, the dovetail jig guides the hand held router, tremendously speeding up the task of cutting accurate dovetails. The tenoning jig safely holds stock vertically on the tablesaw so that the cheeks can be cleanly sawn away either for a few pieces or a few hundred pieces. There are circle cutting jigs for the bandsaw and disk sander which are simple to make. Basically, they consist of a piece of plywood with a wooden or metal runner attached to the underside with screws. Installing a pivot pin at the desired location and drilling a hole into the bottom of the stock allows you to place the stock on the jig, slide the jig into the slot on the machine table and rotate it into the blade, cutting a true circle.
Fingerboards and antikickback rollers are items that I would call fixtures because they are attached to stationary machines. These devices are typically used on the tablesaw, bandsaw, and router table. They do a wonderful job of holding the stock firmly against the fence while ensuring accurate milling operations as well as protecting the craftsperson from dangerous kickbacks.
Another fixture that I find indispensable is my cross cut sled for the tablesaw. I have built many of these to aid in various tasks. They consist of a piece of good quality half inch thick plywood with two wooden runners aligned with the slots in the tablesaw. There is a fence attached to the back which supports the stock. I have designed my fence to be higher in the center so that there are several inches of stock that are higher than the tablesaw blade. As you make a cut with the blade raised to full height you will not cut the fence in half, and because the sides are lower, I have trained myself to always place my hands there as a safety precaution. As long as your hands are resting on the sides of the fence they are not in the path of the tablesaw blade and therefore are out of harms way.
In conclusion, allowing yourself to take the time to properly outfit your shop with jigs and fixtures will not only speed up operations in the long run, it will improve the accuracy and consistency of your machine work. More importantly, it will increase shop safety and as we all know, safety is the number one priority in the shop."
"Jigs And Fixtures One way to look at them is that they are solutions to problem solving. Jigs can be defined as a portable device that guides the cutting tool, while a fixture is something that attaches to a machine and allows the stock to slide while being held firmly. As we explore the various examples of jigs and fixtures, it occurs to me that there is probably some cross over of definition. Either way, these devices, whether manufactured or shop built, are clearly of enormous benefit to the woodworker. For example, the dovetail jig guides the hand held router, tremendously speeding up the task of cutting accurate dovetails. The tenoning jig safely holds stock vertically on the tablesaw so that the cheeks can be cleanly sawn away either for a few pieces or a few hundred pieces. There are circle cutting jigs for the bandsaw and disk sander which are simple to make. Basically, they consist of a piece of plywood with a wooden or metal runner attached to the underside with screws. Installing a pivot pin at the desired location and drilling a hole into the bottom of the stock allows you to place the stock on the jig, slide the jig into the slot on the machine table and rotate it into the blade, cutting a true circle.
Fingerboards and antikickback rollers are items that I would call fixtures because they are attached to stationary machines. These devices are typically used on the tablesaw, bandsaw, and router table. They do a wonderful job of holding the stock firmly against the fence while ensuring accurate milling operations as well as protecting the craftsperson from dangerous kickbacks.
Another fixture that I find indispensable is my cross cut sled for the tablesaw. I have built many of these to aid in various tasks. They consist of a piece of good quality half inch thick plywood with two wooden runners aligned with the slots in the tablesaw. There is a fence attached to the back which supports the stock. I have designed my fence to be higher in the center so that there are several inches of stock that are higher than the tablesaw blade. As you make a cut with the blade raised to full height you will not cut the fence in half, and because the sides are lower, I have trained myself to always place my hands there as a safety precaution. As long as your hands are resting on the sides of the fence they are not in the path of the tablesaw blade and therefore are out of harms way.
In conclusion, allowing yourself to take the time to properly outfit your shop with jigs and fixtures will not only speed up operations in the long run, it will improve the accuracy and consistency of your machine work. More importantly, it will increase shop safety and as we all know, safety is the number one priority in the shop."