Tablesaw Rip Fence Capacity Selection
|Many of the tablesaws on the market
today can be found in either a 30 or 50 inch rip fence capacity version, the same is true
for aftermarket rip fence systems. A very common and reasonable question on woodworking
forums is "what size to get?". Sometimes the choices is easy, if shop space is
very tight, the larger fence size is basically out of the question since it consumes more
space. Otherwise, a little more thought should be applied to the selection. It should be
notes that rip fences can be found in more capacity sizes than just ~30 and ~50 inches.
Biesemeyer for example has fences starting at 26 and ending at 122 inched to the right of
the blade. In this article I'll list a few factors that should be considered when
selecting the rip fence capacity for a tablesaw.
30 is Enough
I've done a little investigation using a sampling of project plans as well as wear marks on my own rip fences. The true need for a rip cut over 30" is actually a pretty rare occurrence. Quite often even when a 30"+ rip is required, the same operation might be performed by ripping the "other" side. For example, say a 40" rip cut is required on a piece of plywood for a cabinet back. The same cut could be made (usually) by making a 8" rip off of the other side to yield the 40" piece required.
When I look at project plans from magazines, my estimate is that a 30"+ rip would be required less than 1% of the time. When I examine the wear marks on my own machine, they are predominantly in the region 12" and closer to the blade. Based upon my experience and the evidentiary need in a survey of plans, there seems to be little evidence for the true "need" for this capacity except on rare occasions. Another item worth noting is that the additional 20" or so of rip capacity is going to consume an additional 4 square feet of shop space for an operation that would be done very rarely.
One oft cited reason for a 50" rip fence is to cross cut a piece of plywood in half (or thereabout). Some may refer to this as "squaring" a piece of plywood. I would like to point out that in this case, the operation being performed is a rip because that's all the saw is capable of doing in this case. More importantly however, a saw cannot really "square" any stock using the rip fence, all it can do is make it parallel. Quite often, that is all that is really desired but some less knowledgeable readers may presume otherwise. In order to really square a piece of stock, a true crosscut operation must be performed. On a tablesaw, the easiest way to do this with a large piece of stock (ie: plywood) is with a sliding table or a crosscut sled; it cannot be done using a rip fence alone.
50 is Better
Quite often the cost difference between a 30 and 50 inch fence is either fairly small or easy to bear. In this case, the simple logic that might be used is "if you have the space, why not get the bigger fence?". This actually makes sense to me, after all, it's harder to add to later and if space isn't an issue, there isn't much else to consider.
However, there are other reasons one might see a need for the larger fence system. For instance, one might simply desire a larger table surface for any reason. Another could be that if a router insert were placed at the right edge of the table, it would be very unlikely that the router fence system would have to be disturbed should the saw be needed to be used for a large rip cut. If the router insert were at the left end of the table, then the larger 50 inch table could still be beneficial as it would allow for a greater throat depth between its cutter and what ever fence system it used. Another reason to get a larger fence would be for resale value since it appears to me that the larger fence size is more desirable to potential buyers.
If your shop space is very tight, the decision has already been made for you, get the smaller fence. If you have enough space, I recommend the larger fence system just because you'll have it to use for whatever you want. Based upon true need though, a 30 inch fence is about all you really need.