This Project also won ‘Best Documented Build’ for March 2016 at Homemade Tools.net
The debate on Radial Arm Saws seems to go on forever. I’m in the “For” category. To help those who may be ‘on the fence’ make up their minds and to perhaps, persuade those in the “Against” category to look again, here is a look at my RAS set-up. It was developed primarily with safety in mind but also convenience and accuracy.
There is little doubt that the RAS is a versatile cutting machine. It can be used for cross-cutting, ripping, cutting mitres and bevels and much more. But like most good things in life, there are trade-offs. In the case of the RAS, the trade-off is simple, if we do not adjust and tune it up properly, the quality and accuracy of the cuts will not be optimum. Slightly off square cuts and burned edges may be the result. Or worse, kick-back when ripping may ensue.
Luckily, all it takes to produce crisp accurate cuts and safe cuts, is a bit of tuning and adjusting every now and then, and safe working procedures. But tuning-up the RAS is for another post. Here, I simply wish to showcase my Radial Arm Saw set-up and to show some of the operations that I perform on the saw.
It is made from melamine-faced particleboard; for ease of cleaning and for slipperiness or slickness, if you like.
Next comes a sideways sliding table (x direction, that is) made from the same material. This might seem a strange idea with and RAS but, read on. This auxiliary table is constructed in a way that it hooks over or straddles the rear fence of the original table in a manner that prevents slop.
Kerf lines are visible on the auxiliary table in the photo from previous ripping operations; the auxiliary table is sacrificial.
The back fence of this auxiliary table is designed to be exactly parallel with the original table’s fence. Examination of the photographs will show that the are three clamping devices which hold down the work piece firmly when cross cutting or ripping. Another important feature of the auxiliary table is a pin which automatically drops into a corresponding hole in the original table’s fence when aligned, thus, locking the auxiliary table into place when cross-cutting, for example.
The following photo shows a board of walnut ready to be cross-cut to length. It is clamped in position, tight against the fence. A stop arrangement to the right ensures that repeat cuts will be exactly the same. The auxiliary table’s lock pin is in the down position, so everything is solid. The cut can be made safely and cleanly with no hands or thumbs needing to be near the blade. In fact, the cut cut could be made with just one hand operating the saw. A word of warning: after a cross cut always let the saw-head slide back to its home position and kill the power and let the blade come to a stop before un-clamping and re-clamping the wood for the next cut. If the cut-off piece is lying in the path of the blade, kill the power and let the blade come to a stop before attempting to remove the piece of wood. Never reach around the spinning blade to lift a piece of wood. These are basic safety precautions with an RAS.
The next photo shows the set-up for a rip cut. Here it is set up for trimming the edge of a board. It could just as easy be for straightening the edge of a board, ripping down the middle or be even set up to cut tapers. My particular set-up has a board-length capacity of about 4ft. This works OK for me as most of my projects do not require boards longer than that. If I want to rip cut a longer board I make special arrangements for that. Ed Waggoner Sr. demonstrates a method that could be used on his YouTube video. For the most part, my set-up works for me; everything is clamped down and my hands and fingers are kept well out of the way of the blade. If you commonly need to rip longer stock, then make a longer sliding table. But make sure there is absolutely no slop whatsoever in the sliding table; it must be dead solid so that the board travels dead straight into the saw blade. I find that a properly built sliding table such as this with adequate clamping, keeps the board much straighter relative to the blade than boards held by hand against a fence. What you don’t want is wobble or wander in the board as it travels into the blade. That is the sort of thing that causes kick-back and also a spoiled cut. Finally, if you are attempting to rip a board,make sure the anti-kick pawls and the splitter are in place.
Here’s a view looking towards the blade. The blade-guard can be seen to the right of the blade in the picture. Just a smidgen (i.e. a small unit of measure in wood-working parlance!) is about to be taken off the edge of the board.
And finally, after the cut; the sliding table has been moved from left to right (from the operator’s point of view standing in front of the table) and the operator didn’t need to stand in the line of fire of the blade. All is done from the front of the table. Once the cut is complete, shut off the power and allow the blade to come to a stop before you attempt to remove the board from the clamps. The table can then be slid back to the start position and a new board clamped in for the next cut.
Now you can see why I wanted to use a melamine faced board for the tables as it slides relatively easily, one sheet against another.
My set-up is also great for cutting medium to small sized sheet materials. The next photo shows a plywood square panel being cut to size. Cutting a panel like this is basically like doing long cross-cuts. The panel is clamped down and temporary block clamped behind the panel determines the length of the side of the board.
And now a nice little jig that simply clamps straight onto the auxiliary table against the fence. Can you see what it is? It may come as a surprise to know that it is actually a circle-cutting jig; and one that works remarkably well. How, you might ask, does one cut a circle (safely) on a RAS?
Well, the principle is very simple: keep cutting the corners off a square shape, again and again. and you will end up with a circle. In other words, a series of cross-cuts (what the RAS excels at). Believe it or not, from set-up to finished circle only takes a few minutes.
The following sequence of photos show the setting up and cutting process:
First setting the jig for a 14″ dia. circle.
Now, see the knob on the left that tightens down the setting on the jig:
Now, imagine the square of plywood we cut earlier; we find its centre-point and drill an appropriately sized hole and drop it over the pin on the jig. Now, we simply hold it (firmly) in place and cut off the first corner; just as if we were doing a regular cross-cut.
The photo above shows the first corner cut off. It is now only a matter of rotating the plywood 90 degrees and cutting off the next corner and so on. When all four corners are cut off, we start on the next lot of smaller corners until we end up with what we see in the next photos:
A near-perfect circle and a little pile of (triangular) debris.
All that is left now is to lock the blade-head at the appropriate position along the arm and turn the disc-shaped plywood into the blade to trim off the hairs:
. Don’t be in a hurry; make sure all possible corners have been cut off the disc before performing the last operation.
Of course, a Radial Arm Saw is capable of doing all sorts of unusual jobs but I will cover just one more of the common tasks that I use the RAS for; cutting mitres (perhaps ‘miters’ where you are). Again, this requires only the simplest of jigs clamped down onto the auxiliary table; a fence fixed at the required angle to an accurately squared piece of MDF :
The final photos show a mitre (miter) after being nipped off the end of a 2″ strip of plywood and the cut being checked against a 45 degree square. Looks pretty accurate to me!
To conclude; I designed this set-up primarily with safety in mind. Secondly with accuracy and thirdly with convenience in mind. I hope it will persuade some of the Naysayers that the RAS is not so bad after all. Indeed, it is pretty well the mainstay of my shop. Few projects take place without some recourse to my RAS. Moreover, it is no more dangerous (and no less forgiving) than any other machine. As with any machine, it must be treated with respect. All machines are dangerous. Even hand tools can be deadly if incorrectly used. So, whatever else we do, let’s think safe and keep safe.