By Phil B Follow
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About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first to… More About Phil B »
The radial arm saw is a very versatile machine around which a whole shop can be built. It is one machine that allows a number of operations normally requiring different specific machines. Unfortunately, electric miter saws have displaced the radial arm saw. That is probably because many used a radial as only a glorified miter saw or cut-off saw. This Instructable will pull together in one place a number of Instructables demonstrating various capabilities of a radial arm saw, as well as some dealing with wear and maintenance issues. Just click on the hot links in the frames below.
The radial arm saw has several adjustments that need to be aligned properly for accurate cuts. These do have indexed settings. The owner/operator must set these properly. They include setting the tilt of the motor so the blade is 90 degrees to the table. The arm can swing and must be set so it is 90 degrees to the table's fence. The most cumbersome adjustment in my experience is getting the arm 90 degrees to the fence. But, with a slight revision of the process outlined in the owner's manual and an addition to the table, it is not difficult at all. In use vibration can change the settings of any saw a little. The the saw needs to be checked occasionally to make certain the arm is still square to the fence.
The radial arm saw is very handy for cutting pieces to length. Most often these cuts are at 90 degrees to the length of the piece. Sometimes they are cut at an angle, whether 45 degrees as shown in the photo, or something else. Although the arm has an angle gauge and pointer, the safest procedure for accuracy would be to make a test cut on scrap. Next best is to use a "T"-bevel square to set the blade travel on the arm.
When cutting many pieces to the same length, some like to make a movable stop that clamps to the saw's fence. While most of the Instructables linked in this Instructable are mine, this particular one is not.
A radial arm saw normally requires swinging the arm to the right or left in order to make 45 degree miters. A stationary miter sled makes cutting accurate miters more sure and much easier.
Using a radial arm saw for rip cuts is very much like making rip cuts on a table saw, except that the saw blade is mounted above the table rather than coming up through the table. When I first began to use a radial arm saw, I found I needed to pay special attention to brushing away sawdust and wood chips that gathered on the table at the fence. As with a table saw, a splinter of wood caught between the fence and the work piece affects accuracy.
The radial arm saw motor has an in-rip and an out-rip position. Choose the one that is most comfortable for your job. The in-rip position places the blade end of the motor closer to the fence. The out-rip position places the blade end of the motor nearer to the front edge of the table.
The front edge of the table can be used as a saw guide for special ripping operations, as when the edge of a panel needs to be made true.
I once attended a radial arm saw demonstration by a representative of Black & Decker. He said their saws were superior to my Craftsman radial because the motor carriage yoke on their saws is cast iron and it wears better than the aluminum alloy used on Craftsman saws. The wear of which he spoke meant the in-rip and out-rip indexing holes would no longer be 90 degrees apart from the crosscut indexing hole. In a few years I learned I had the problem of which he spoke. Eventually, I developed a very good solution to the problem. And it is not difficult at all to apply.
After crosscuts and rip cuts, I most often use my saw as a grinder. The 5/8" shaft accepts grindstones and cutting wheels of all kinds. It is a very handy tool if you do not already have an electric grinder. The one disadvantage is that you may need to change a setup you worked carefully to achieve so that you can grind for a few minutes, but that is very seldom.
I use my radial arm saw to sharpen my lawnmower blade to a very uniform cutting angle. One of my favorite tricks is to grind something on my radial arm saw while it is chucked and spinning in an electric drill. It is a type of improvised lathe. See step # 2 in this Instructable. Sometimes I make a special wooden jig to hold something just right so I can grind it rather precisely. (The photo with this step of this Instructable is part of the Instructable linked in the preceding sentence.) I improvised a way to cope metal tubes for welding at a right angle. It uses a cutting wheel on my radial arm saw and a small wooden table I made to elevate the work so it is nearer to the level of the motor's shaft. While my method worked for me, since I have learned about another Instructable that would be easier and even better for the same task. I also use my radial arm saw when I use a special jig to sharpen drill bits.
After grinding with my radial arm saw, the most useful thing I do with it involves a sanding drum. The back end of the motor shaft on my saw is machined to receive 1/2" x 20 thds. attachments. I have a Craftsman sanding drum that screws onto the motor shaft.
I do not have a planer/joiner, but learned of a way to use a sanding drum and a fence to joint wood so precisely that the eye has a difficult time finding the glue line. I use the sanding drum and the small wooden table mentioned in step 5 for thicknessing wood to a precise dimension. Whereas my sanding drum's face is only 3", the pieces I thickness almost need to be no wider than this size. This process may not be quite as good as if I had commercial machinery designed for just this sort of thing, but it has allowed me to glue up panels, as you would for a tabletop.
The back end of the motor shaft also accepts a 1/2" Jacob's drill chuck. This is handy for drilling or for grinding small items.
I developed a way to do concentric drilling on my radial arm saw. I have not needed this often, but it has come in very handy a couple of times, and the results were very precise.
I have also done some precise drilling by using the little table shown in previous steps and clamping a fence guide to it. The choice is the user's as to whether to pull the motor into the work or push the work toward the motor and the bit.
