The Radial Arm Saw -- a Guide of Sorts

260,196

198

123

Introduction: The Radial Arm Saw -- a Guide of Sorts

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 ...

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.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Aligning the Saw

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.

Step 2: Cut-offs or Crosscut Sawing

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.

Step 3: Rip Cuts

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.

Step 4: Eventual Wear That Ruins Accuracy

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.

Step 5: Grinding

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.

Step 6: Sanding Drum Operations

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, butit has allowed me to glue up panels, as you would for a tabletop.



Step 7: Concentric Drilling

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.   

Step 8: Cove Cuts

A radial arm saw can do cove cuts to make bowls or picture frames.

Step 9: Pin Router

Once I needed a pin router setup and made an attachment for my radial arm saw and router.

Step 10: Curved Molding

I also developed a way to make curved molding on my radial arm saw.

Step 11: Rotary Planer

Craftsman sold a rotary planer attachment for the radial arm saw.  It fastens to the blade end of the motor shaft and uses the blade retaining nut.  It was sold for reducing the thickness of a piece of wood.  You can do that, but it leaves deep circular rings, especially if the work jumps a little in use.  Leave a little extra thickness and do some work with a belt sander to get the piece ready for finishing.  I needed to tilt the motor so I could use the rotary planer to shape a bevel on the end of a piece of plywood for some special car ramps I needed.  See step # 8 of thisInstructable.  I also used the rotary planer in step # 16 of this Instructable.


Step 12: Replacement Switch

I have had my radial arm saw 38 years.  During that time I have worn out one set of motor bearings and three motor switches.  There came a time when the factory switch was no longer available, so I adapted a switch from Radio Shack.

Step 13: Missing Table Clamps?

If the table clamps are missing from your saw, you can make your own.

Step 14: Adapting Blades to a Sawsmith

During the 1950's and 1960's the Sawsmith radial arm saw had quite a following.  Many are still devoted to it, but it uses an unusual blade size.  The arbor hole is 1 1/4" instead of the more usual 5/8" one sees today. I adapted a 5/8" arbor blade for a friend with a Sawsmith.  You might be interested in this in case you would buy a Sawsmith at a sale one day. 

Because radial arm saws are no longer as popular as they once were, you can find some really good deals on them at sales, on eBay, and on Craigslist.  They make a great main tool for any workshop.

Participated in the
Craftsman Tools Contest

Be the First to Share

    Recommendations

    • Magnets Challenge

      Magnets Challenge
    • Snow Challenge

      Snow Challenge
    • Wearables Contest

      Wearables Contest

    123 Discussions

    1
    nvmoose
    nvmoose

    Question 3 months ago on Step 1

    I have an interesting problem. After adjusting the saw completely as outlined by the owners manual and your additional tips here in your instuctible I can crosscut at a perfect 90 degree. The problem is that when I try to cut a perfect square out of 1/2 inch plywood the fourth side is always a bit out of square. I start with a true edge and make the first cut and check for square...perfect. Turn piece counterclockwise and make second cut and check for square...perfect. Then once again for the last cut and it's out of square to the original true edge. I've tried this multiple times with different pieces of plywood and making micro adjustments to the saw and flipping the piece over to help. I can always get three sides perfect square and one out. BTW I have a 1964 Craftsman Radial 100. Found on craigslist for $20 bucks. Basically a rust bucket that I rebuilt de-rusted inside and out and have tuned to this point. Thoughts about it squaring three out of 4 sides no matter which way I cut?

    0
    Phil B
    Phil B

    Answer 3 months ago

    Congratulations on getting a good saw at little cost. Your problem reminds me of the six sided end tables I made for my wife about forty years ago. No matter what I did I could not get six equal corners. Each corner was imperfect by a tiny, tiny part of a degree. Like you, I cut one corner and then used that cut as the basis of the next cut. My tiny error became cumulative and compounded itself by the time I got to the sixth cut. I had even used a feeler gauge to bump the arm a few thousandths of an inch in search of a more accurate cut. I finally gave up and cut the final miter for the solid pieces around the six sided top to fit rather than according to the proscribed number of degrees in the ideal corner. The error is not large enough to be noticed by anyone. I think what you are experiencing is just part of life in an imperfect world with normal workshop tools. If I were doing your project, I would likely cut the first 90 degree corner as a crosscut. Then I would set up for rip cuts. I would use one side against the fence to cut the parallel cut opposite it. Then I would turn my piece a quarter turn and use the side cut by the crosscut to rip its opposite parallel side. You may still have a minuscule error, but it will not be compounded.

    0
    nvmoose
    nvmoose

    Reply 3 months ago

    Thanks Phil,

    I was kind of going that direction in my mind this morning. The cumulative effect. Funny thing is I don't really need to cut a perfect square for any particular reason right now. I was just checking the saw for square. I too was using a feeler gauge for micro adjustments. I will try the ripcut method you described to see if I can get a true square. Did you say that you changed the motor bearings on your saw? I hear a bearing squeal every once in a while. The squeal is reminiscent of an old craftsman router I had to put bearings in once and I think my time is near with the RAS.

    0
    Phil B
    Phil B

    Reply 3 months ago

    I replaced motor bearings in my RAS back around 1985. Sears wanted around $8 each. A local bearing shop sold me the same size bearings for about $6 each. A couple of years ago I replaced a very similar bearing on a NordicTrack ski machine, and prices have really escalated. On occasion I have gently pried the seal off of one side of the bearing and added wheel bearing grease. Then I gently used a hammer to make the seal as much like new as possible and nudged it back in place. That does not work if the bearings are rusty or pitted.

    Do you know the trick of cutting two squares of thin plywood or Masonite about 12 x 12 inches? Put one on top of the other and trim edges simultaneously for the best square corner you can make. Then flip the top one over and slide them together against a straightedge. Look for any signs of a “V” opening that indicates a slight inaccuracy.

    0
    nvmoose
    nvmoose

    Reply 3 months ago

    Hi Phil,

    I guess I will just wait until the bearings wear out completely on my RAS. When I replace the bearings in my craftsman router I think the price was 25 bucks for both bearings. If I remember correctly they were both of a different size and I found each one on eBay separately. $25 was not a bad price to restore a 1/2 inch commercial grade router that I received free from a friend. This router is circa 1960's and is a beast.
    I used the RAS yesterday quite a bit and it worked just fine. No bearing squeal. I was just doing some cross cut work so I wasn't working on making anything square. I think I will just use my tablesaw for the final square cuts on any piece I'm working on. But no, I have not heard of using two 12 x 12 pieces as a cutting strategy but I DO see how this can work. My main focus was just getting true 90° square corners x4 on any given piece whether it be square or rectangle. Soon I will be cutting multiple cabinet door panels for a small teardrop trailer I am building. I will also try the out rip method you described earlier, that might work also.
    Once again, thanks for the help.

    0
    SeanA5
    SeanA5

    Question 6 months ago on Introduction

    Great article! I was just starting to use my wife’s great grandfathers craftsman radial saw and the motor burned out. Do you have any advice for repair or replacement? I’d prefer repair. Thank you

    1
    Phil B
    Phil B

    Answer 6 months ago

    Check eBay for a replacement motor, but be certain it fits a saw with your saw’s model number. Maybe contact people selling parts from radial arm saws and ask if they have a motor or know where to find one. There is probably an electric motor shop near you where your motor can be rewound.

    0
    GeorgeJ87
    GeorgeJ87

    Question 1 year ago on Introduction

    I recently purchased a used saw like the one in the picture at a garage sale anyone know the year and or model number.interested in finding an owners manual for it

    0
    Phil B
    Phil B

    Answer 1 year ago

    The model number should be on an aluminum plate on the side under the table. These were made from the late 1940s through the late 1960s. Somewhere on mine there is a month/year code that is pretty obvious.

    0
    RonK65
    RonK65

    Question 1 year ago on Introduction

    Hi,
    I recently picked up an old Sears RAS similar to what is in your pictures. After a few uses, the arm started to move. I researched and tighted up the 9/16 head bolts to no avail. Any suggestions?

    0
    Phil B
    Phil B

    Answer 1 year ago

    Ron,

    I have been thinking sbout your problem. I assume you mean you have locked down the knob on the arm, but it is still able to move a little left and right. Does the indexing pin fall into place? Can you tighten the knob?
    I have never taken apart the mechanism that keeps the arm from moving on the column. Those who have complain about great difficulty getting all of the pieces back together in working order. I am wondering if a previous owner took the locking mechanism apart and did not get it back together again properly.

    0
    RonK65
    RonK65

    Reply 1 year ago

    Thanks for the reply Phil. Its worse than you assumed, and I didnt tell you but there is no knob on the arm. Makes me wonder if that is why it freely swings left to right unless I really bear down on the adjustment bolts. I have also read tearing it apart can be a challenge. I'm thinking next I should see if I can get inside to lock at least at 90.Thoughts?

    0
    Phil B
    Phil B

    Reply 1 year ago

    Is the saw designed with no knob at the end of the arm, or is the knob simply missing? Some saws had an “L”-shaped lever on the side of the column to index the arm and another lever with a screw theead to lock the arm in place. There are people selling parts of these saws. You may be able to pick up an entire arm for your saw. eBay is one source. I also found a guy who apparently has bought up quite a few parts for these saws. I will need to check with him about giving out his name.

    0
    SandiG15
    SandiG15

    Question 1 year ago on Introduction

    Hi Phil,

    Can you tell me how the arbor (red button on back of saw) works & what it's used for? (You may not know it as an "arbor" so set me straight if I'm calling it by the wrong name-just heard it called that in a video.) I can't find any instructions about it in the manua.

    0
    Phil B
    Phil B

    Answer 1 year ago

    This is my second response. There may also be a red reset button. If the motor overheats, the reset trips the circuit to protect the motor. Pressing the button closes the circuit again.

    0
    Phil B
    Phil B

    Answer 1 year ago

    First, the colored buttons were a sales gimmic by Sears/Craftsman to make the saw seem easier to use because a colored scale on part of the saw matches and is controlled by a button or lever with the same color on it. Other manufacturers, even earlier versions of the same saw may not have colors.

    The arbor is the shaft in the motor. What appears as a red button on the end of the motor arbor opposite the blade end is probably not a control button, but a thread protector. It screws off to reveal a threaded end of the shaft useful for attaching a 1/2" drill chuck or a sanding drum.

    0
    LuiP6
    LuiP6

    Question 1 year ago on Introduction

    Can you name the parts of the radial arm saw and their uses

    0
    Phil B
    Phil B

    Answer 1 year ago

    I am assuming radial arm saws are not often seen currently where you live. They have become less popular and less available in recent years. In some parts of the world they may never have been available and many have never seen one.
    A radial arm saw allows you to cut wood to length with 90 degree cuts. This is done by pulling the motor carriage (on rollers) toward the operator with a stiff arm and shoulder to keep the blade from grabbing and propelling itself toward the operator. (If the saw is properly aligned, it does not bind, and this is not a problem.) The blade may be tilted to cut with a bevel cut. A knob and a locking pin near the handle on the motor carriage are used to change the tilt of the blade. Another knob cranks an elevation screw that raises the motor or lowers the motor by raising or lowering the arm on which the motor carriage is mounted. That means your cuts can form a dado groove rather than a complete separation cut. The motor carriage has a locking lever and an indexing pin that can be used to swivel the motor 90 degrees to the left or to the right. This is for making rip cuts. A fence on the saw table guides the wood. There are two swivel positions: an inrip and an outrip position. These are necessary so any width can be ripped. Two positions are necessary because the blade is offset from the swivel axis. (Cross cutting keeps the wood stationary while the saw motor moves. Rip cutting keeps the motor in a stationary position while the wood is fed from one side of the saw table to the other, much like ripping with a table saw. The arm may be cranked up to make a dado cut rather than a separation cut. The blade may also be tilted to make a beveled rip cut. And, a knob on the arm can be loosened so the arm can swing 45 degrees to the right or the left for making miter cuts. An index pin on the arm helps lock the arm position at 45 degrees left, 90 degrees, and at 45 degrees right.

    0
    Edoten
    Edoten

    2 years ago

    I got my last RAS from a friend and I cannot get it to go up and down. I used break free and loosened the bolts and screws in back of the shaft and it will still not go up and down by turning the handle in front. Please help. It is driving me crazy. thanks. Ed

    0
    Phil B
    Phil B

    Reply 2 years ago

    I am assuming you have a Craftsman saw like the one in the photos. As you know, the crank turns a shaft that goes to a set of gears to turn a threaded shaft inside the column. If the arm is already too high, the screw threads will disengage from the arm, but I doubt that is your problem. Are your gears stripped? Is a pin connecting a gear or the crank to the shaft sheared? To my mind it has to be one of those things. Also, make certain the wedge assembly that eliminates side to side movement of the arm is not too tight.