Innovations are born out of a person’s ability to see a problem and come up with potential solutions. Each potential solution must then be evaluated to determine its practicality. Sometimes, the answer turns out to be so simple that one would think it should have been obvious. This is definitely the case with a track saw.
One basic problem that was addressed with the concept of a track saw was that of establishing a straight edge on a sheet of plywood. It’s surprising how often the edges on a sheet of plywood aren’t straight. Working around this problem in a very small shop where a sliding table, beam saw, or a CNC router isn’t available is awkward. Inefficiency in the use of time and material is inevitable.
I used to nail a straight strip of wood (usually thin plywood) to the top of a sheet of plywood, overhanging its crooked edge. The strip would ride against the table saw fence to establish a straight edge. I’d set the fence at a distance wide enough so that I would have enough material clear of the nail holes for the finished part that I needed. After I made that first cut, I’d then spin the part around and cut it to the finished width. This method created clean, straight cuts on both sides of the blade but it was wasteful. The material that contained the nail holes was unusable for high end finished work.
Another alternative was to use a straight edge to guide a portable circular saw. In this case, the cut was rough and tear-out on the top, normally the finished surface, was inevitable. The result was that I still had to take the additional step of cutting a part oversized on the table saw and then trimming to the final size. In fact, since both sides of the cut were rough, I had to go through this oversizing process for the remainder of the sheet, as well.
So, the first problem addressed by the development of the track saw was the roughness of the cut. The solution was simple: improve the quality of the saw and blade to get a smoother cut.
The second problem was the tear-out on the finished surface. A partial solution to this problem was also simple: make it easier to adjust the depth so it becomes practical to first score the finished surface with a shallow cut and then make another pass at full depth to complete the cut.
A further improvement to the track saw could be made by providing multiple depth stops such as those on a plunge router. The ultimate solution would be to include a scoring blade. That way, a tear-out free cut could be accomplished in a single pass. I wonder how much that would add to the cost.
Another problem with the circular saw and straight edge system is the need to measure the offset from the edge of the blade to the edge of the base of the saw that is guided by the fence. A homemade solution is to fasten the straightedge to the top of a strip of thin plywood on which the saw would sit. Running the saw over it once would create an edge on the plywood strip exactly at the edge of the saw blade. Then all you need to do is line that edge up with your marks on your workpiece. The solution accomplished by the track saw is the same but the plywood is replaced by an aluminum extrusion with a plastic edge.
A circular saw can inadvertently wander away from the straightedge when making cuts in difficult working conditions. With a track saw, a raised section of the extruded track guides the saw by means of a corresponding groove in the base of the saw. This system eliminates the possibility of wandering off track.
The ability of being able to move the saw instead of the material makes it easier to cut full sheets of material in a confined area. The same is true for those who find it physically difficult to lift and guide a full sheet of material through a table saw. The best solution is to use the track saw to cut the sheet into manageable pieces with at least one straight edge and a perpendicular adjacent edge for each piece. Once that’s established, it’s much more efficient to use the table saw for subsequent cuts. The following paragraph explains the reason for this.
One drawback to using the track saw is the need to measure and mark key locations of the cut you plan to make, usually at each end of the cut. The marks must be accurate and the track must be aligned accurately with those marks and then secured. Although the bottom of the track includes material to help hold it in place, I like to clamp it securely with the clamps that slide in a groove on the underside of the track. This process is time consuming compared to just setting the fence on the table saw and pushing the pieces through.
In using a track saw, it’s important to have the right location to set up for cutting. The sheet material needs to be set in a level place with good support on both sides of the cut while maintaining a clear path for the saw blade. You don’t want to be cutting into anything below the material unless it’s something you plan to sacrifice. Some people use rigid insulation for that purpose.
Another advantage that the track saw provides is the ability to cleanly cut sheet material at angles other than 90 degrees. The bottom piece of a corner cabinet is a common application. Since the cut is clean, you no longer need to clean up your cuts with a router guided by a straight edge.
Another situation in which I found a track saw to be a tremendous help was in cutting an angle on the end of a cabinet face frame where it was to meet a corner cabinet. I left the stile square-edged and a little oversized when I glued up the frame. The face frame was long enough that a table saw cut would have been awkward, at best. The track for the track saw clamped on easily and made a perfect miter cut, even with a slight bow in the stile.
Although the better track saws are expensive, the ease of adjustment and accuracy of the cut make them well worth the money. It’s amazing how conceptually minor improvements in a tool can make it the best solution in a situation where previously it would have been less than ideal.