|
Recently I had the honor of receiving an email from Kelly Mehler regarding this particular subject. If you haven't arrived here by way of his web page, you can check it out here for more information on safety, where to catch his seminars, or take a class. In fact, The Tablesaw Book was recently released as a second edition. Kelly is very concerned about tablesaw safety and it was my distinct pleasure to have him link this review.
Howard Ruttan
February 21, 2003
Probably since Kelly Mehler's article appeared in Fine Woodworking nearly a year ago, the sales on these babies have gone through the roof. Table saw manufacturers should be dipped in honey and covered in ants for selling the boat anchor they call a "blade guard" as a stock item. Mine wouldn’t even be a good anchor. Mehler's article in FWW #152 (November/December 2001) compared the aftermarket splitters and blade guards available today. It is important to note that, apart from what the saw manufacturers would have you believe, they are two distinct items that perform two very different functions.
A blade guard is a barrier. That's it. It is a physical entity that comes between your fingers and the spinning blade. In rare instances it may keep a piece of wood from flying up in your face, but kickback tends to send the projectile flying right back, within very few degrees of a completely horizontal trajectory. The blade guard itself does not prevent kickback. For a "cheap Scotchman" like me, $500 for a piece of Plexiglas on a stick seems to be a bit much to pay. Call the safety police if you like but I do have a healthy respect for the damage my saw can do and I do want to protect myself from it. A homemade blade guard can function just as well and costs a whole lot less.
A splitter is a piece of metal, or some other material, that is in the same plane as the blade and mounted in the saw directly behind it. A piece of wood sandwiched between the blade and the fence can get knocked askew of its path and wedged between the spinning blade and the fence, or simply caught by the teeth of the blade. The piece becomes momentarily lodged there while enough force builds up to break it loose, much like an earthquake. Then the motion of the blade, the source of the energy and a constant force directed toward the rear of the saw (and the operator), carries the now dislodged piece of wood in a nearly horizontal trajectory toward you or what ever is behind you. I have put holes through framed walls this way. The only way to really reduce this danger is to use a splitter. The splitter helps to keep the wood that has passed beyond the blade straight so that it cannot get bound up on the blade. Sometimes, when cutting a piece of freshly planed lumber, especially if it is quite long, as the blade passes through tension is released in the wood causing the kerf to close up after the blade, pinching it. This is also highly dangerous but a splitter will keep this from occurring. In my mind, design and accuracy in construction is more important for a splitter than a blade guard.
The Mehler article introduced me to a splitter assembly that could be purchased inexpensively, removed easily, and was rated to perform at least as well as its well heeled cousins. At around $30 it seemed like a great choice as a replacement for my stock splitter. As for the blade guard, I'll post an article when I get my own design finished.
Thanks to Kelly Mehler, I was armed with the part number of the Delta removable splitter (No. 1349941). That was fortunate. I have access to only one woodworking store in my vicinity - Woodworker's Warehouse. Their salesman looked at me like I had three heads when I tried to purchase it there. My personal thanks to Delta parts (1-800-223-PART) who had it and shipped it -lightning fast.
The splitter arrived in excellent condition, well packed, and complete. I unpacked it and looked it over and was puzzled as to how to assemble it. Unfortunately, being sold as a replacement part, it came without instructions. The fine folks at Delta customer service were kind enough to fax me the instructions for installing the splitter on my saw. Although the quality of the photos suffered form being photocopied then faxed, the procedure seemed very straight forward.
The fit and finish of the parts was top notch. The powder coated splitter itself was smooth and substantial, and looked as though it had the heft and size to perform even on 12/4 maple. Although the machine parts were cleanly milled, the splitter blade seemed somewhat bent and I was concerned that it would jam during operation. I tried, gently and only once, to bend it straight but the material is very strong and I was afraid of causing damage if I exerted too much pressure. I took this as a good sign and figured I could deal with the problem after everything was installed and in place.
Before installing I took the time to check my blade for parallelism with the mitre slots, and I ensured that my fence was also in perfect alignment. I decided that if I was going to spend the time to align this splitter properly, the whole saw better be well adjusted.
Obviously, the first step is to remove the stock blade guard bracket. Mine was attached to the cast iron trunnion with two Allen head machine screws. Removal of the top screw and loosening of the lower one, allowed me to pivot the old plate and pull it out. Don’t throw away any of the old parts; you may need them later. I did. I will elaborate on that in a minute.
I should point out before I forget that, although it is not specified in the instructions, you should remove the saw blade and lower the carriage to its lowest position. Even after doing this, if you have large hands like mine, you will have a devil of a time getting your hands in there. It's terrible! You may want to consider opening the motor cover and taping a piece of plastic - sized to fit the inside of the saw cabinet - to the interior walls. I dropped the blessed screws and nuts more times than I care to remember, and even lost a part. The area you have to work in was not meant for big hands turning little screws in tight spaces.
The splitter is designed to work on a number of saws so you get more hardware than you need. Aside from having to work in cramped quarters, once you assemble the spring loaded nut onto the bracket, only two screws are between you and the finish line. Both screws mount the bracket to the trunnion and fit through a separate bushing. It was one of these that I lost. Fortunately I was able to use one of the cap screws that held the original bracket in place.
I tightened the bracket mounting screws finger tight then, using the metal straight edge from my combination square, I aligned the face of the bracket that meets up with the splitter blade with the arbor flange This took a few minutes and was a somewhat finicky job. It didn't help that I lost one of the bushings as I was working with machine screws requiring two different sizes of Allen wrenches. That was all my own fault.
Once I was satisfied that the bracket was aligned and tight, I installed the splitter itself, then replaced the blade and throat plate. With the splitter in place be careful replacing the throat plate. You have to hold it nearly vertical to get it to fit around everything if you leave the blade up.. Naturally, if you think about it ahead of time, and lower the blade, you don’t have the little problems that I do. I must be getting old.
At this point I realized that the bend I originally noticed in the splitter plate itself was going to present a real problem. If I had tried to pass a piece of wood through the saw with it in this condition, I would have been in deep trouble. Fortunately, a little sideways pressure seemed to bend it straight without having any deleterious affects on the splitter or the alignment of the bracket under the table.
After using the splitter I feel more comfortable about my ability to avoid kickback. As mentioned earlier, this won't prevent me from physically contacting the blade but I am presently working on a solution to that problem and will post the results when I am satisfied with that solution. The splitter itself is good and sturdy, and it is relatively easy to replace and remove. Although not as quick to use as the disappearing splitter I was originally interested in, the splitter plate on this removable version is much beefier and about a fifth the price.
As for Woodworker's Warehouse, within weeks of inquiring about the splitter they started carrying it as a stock item. If you do pick one off of the shelf in the store, open the package and inspect the contents to make sure you get a flat blade. The bend in mine was not due to shipping or mishandling. It looked like sloppy quality control in the factory. There was no reason to ship it in a warped state. It just wasn't flattened properly after performing the many bending operations required to shape it.
Compared to the stock splitter, there is no contest. This product is far superior and available at an unbelievably reasonable price - which is probably why it is becoming more widely available. When you compare this product to the blade guard/splitter packages out there, you are getting the lion's share of the protection and you aren’t paying hundreds of dollars. There are plans for blade guards on the net, like those on Al Amaral's very popular web site, but I prefer to design my own.. When I come with something that works for me I'll be all set.
|
