Radial-Arm Saw Cutting Technique

Radial arm saws have their place, some cabinetmakers say. Here, they discuss blade choice and cutting technique. November 25, 2005

Question
I just fired up an old (1965) Delta radial arm saw to use for rough cutting stock to length. I admittedly have rarely had the opportunity to use a RAS in the past, so this seems like a real basic question. If I pull the blade through the stock, it wants to climb and bind (or maybe bind, then climb) in the stock. Pushing cuts nice, but loading the stock is a pain. What's the correct approach? The blade is a basic combination blade. Will a better blade function better?

Forum Responses
(Cabinetmaking Forum)
From contributor F:
I have never gone for the "push the saw through the board towards the fence" approach, but I know it works well and some guys swear by it. A sharp blade will definitely help a lot. Also, since you are new to the saw, it will take some time to get used to how hard to pull the saw to avoid climbing.

I have a very heavy old Dewalt 14" and like you, I use it strictly for rough crosscut. The heaviness of the saw makes it less prone to climbing. One thing I always do to set up a radial arm saw that helps prevent climbing and also makes the saw safer is attach a weight to the saw carriage. I am always nervous that a radial arm saw will creep forward and try to trim my fingernails, so I take something heavy like an old sash weight or two and attach it to a steel cable. I run the cable up the wall behind the saw and through a pulley attached to the wall at the right spot and then fasten to the back of the saw carriage. This arrangement makes it harder to pull the saw forward, thereby reducing the tendency to climb, and then the weight makes it easier to push the saw back behind the fence after the cut.



From contributor R:
I use a 14'' Maggi for every crosscut in my shop. It will cut squarer than plywood comes from the plywood mill. You need to get a negative hook blade, made just for a RAS, not a 12'' blade that goes on a mitre saw. The wrong blade will make it climb on top of the wood, warping the arm. If an industrial grade RAS has never been abused, misused, or accidentally damaged, and is set up properly, it is a valuable machine. It takes squaring arm to fence, then blade to arm, then blade 90 degrees off table top, sometimes shimming the guide rails inside the arm. If the rails are straight, it will cut straight. And the proper blade is important. Anyone bad mouthing an RAS is just showing that a piece of cast iron is smarter than he is. -2 degrees to a -7 degree blade should get you sawing.


From contributor M:
Ditto to the above. We also have a Maggi 14" with a 24" cut capacity, which we use to cut our door panels to size. Prior to getting our Whirlwind upcut saw, everything that needed to be cross cut was done on the Maggi. No special setup is needed, so it is always ready to cut. I could not see using a sled on a table saw. We have never used any kind of special blade. I will have to try the negative hook blade as suggested. As a matter of fact, one of the three pieces of equipment I started with was a Craftsman RAS. I later realized what a piece of junk it was, but it sure made do for a time.



The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor D:
There is only one really safe way to cross cut on a RAS - by putting the stock against the fence and then pulling the yoke and blade towards you. This is, technically, a climb cut since you're feeding the blade to the stock in the same direction the blade is rotating. Yes, the blade can "climb" into the stock and the motor can jerk towards the operator. However, that's why you should pull the yoke through the stock with a bit of a "stiff arm" (so to speak), to minimize motor movement should this happen.

In my opinion one should never use a pushing movement back through the stock and against the direction of blade rotation. There are two important safety reasons for this. First, the blade will tend to lift the front of the stock off the table and possibly throwing it into the blade. Second, if the blade hits a hard spot in the wood it can kick back powerfully and suddenly push the motor back at the operator. Both these dangers far, far outweigh the rare possibility of the blade "climbing" through the wood on a normal pull-cut. Further, if on a normal cut the blade does try to climb it forces the yoke upwards against the radial arm which in most instances will stall the blade before if moves very far towards the operator.

I've used a 10" Craftsman cast iron RAS for over 30 years and only had one or two instances where the yoke tried to "climb" - and neither was too harrowing. The key to any RAS is ensuring it's accurately set up in the first place, and regularly checked. This will, in nearly all cases, ensure the saw can be used safely and accurately.



Comment from contributor A:
The radial arm saw if accurately set up and properly used can be one of the most accurate and versatile tools in the workshop. If you find the tool has a tendency to 'climb' onto your stock a few items to look into would be; too fast of a feed rate, a worn or damaged blade, a yoke assembly that is out of square or worn motor shaft bearings. All of these items are easily remedied in a short period of time. Take time to set up a precision tool properly and it will do a lot of precise work for you for many years. I have an older model 10" Craftsman with a few accessories and would not part with it.