One universal need we woodworkers have is an extension table for our table saws. We have all seen dozens of versions of home made extensions with all kinds of features, even including things like a built-in router station! Being no different I found myself needing one to handle the unwieldy 4' x 8' sheets of plywood. However my work space is somewhat limited so I also need the table to be as compact as possible. I have the common Grizzly Chinese contractor 3hp, 10" saw that I imagine a lot of you out there have. Here is how I solved my problem.
Step 1: Features of My Table Design
The key to my design is having a Shop Fox fence installed on my saw. Most mid-priced saws come with fences that are incredibly inadequate. Mine was made of pot metal and had to be squared with the blade every time I moved it. It even deflected when a board was shoved through my saw. It finally died a merciful death when the pot metal locking rod nut broke in half. I sucked it up and bought a Shop Fox aftermarket fence which cost half as much as the saw did at the time but the investment has paid dividends ever since with higher quality projects. The lead photo of my system shows the Shop Fox comes with 3" x 3" angle iron mounting rails that bolt to the front and back of the saw and provide for a 3' extension table to the right of the cast iron bed.
I used the angle iron bracket on the back side of the saw as a key part of the table I built. My table folds down which is not unique, a lot of the designs you see do that. The unique part of my design is the table slides to the left of the cast iron saw bed about 18". This supports the out-fed plywood sheets so no matter how big or small a strip you cut off the sheet, the entire board is supported through the cutting process. It turns resizing big sheets of material into a true one-man process.
Step 2: Making the Slide Mechanism
The first thing to make is a small, non-folding extension that sticks out just past the motor on this type of saw. On the bottom of this table is attached a 1 1/4" square thin walled steel tube via sheet metal screws through the top of the table. This tube rests and slides on the 3" angle iron bracket of the Shop Fox fence. I found that the stack if the tube, a 3/4" MDF top and finally a 1/4" thick Masonite topper was the perfect thickness to be just shy as high as my table saw cast iron top. The topper is attached with 1 1/4" counter sunk drywall screws. Thus project boards slide easily onto the extension without catching but are well supported for the duration. A 2x4 is attached to the front edge of this little table to, a) slide on the support bracket and, b) accept the piano hinge for the big table.
I cut some notches in the top of this table sandwich with my dado blades to allow my miter gage to slide through without obstruction.
This little table needs to be supported on the extended end so I built a bracket of angel iron as shown in the first photo above. The bottom of the brackets bolt to the legs of the was using bolts that the saw uses. The back of the bracket bolts to the 3" angle iron Shop Fox bracket with 3/8" bolts that screw from the bottom into holes I drilled and tapped into the angle iron. The bolts are 1 1/4" long so stick up well past the bottom of the square steel tube.
Here is the key to make the table slide back and forth. I slotted the bottom of the square steel tube with a slot that is just slightly larger than the two bolts sticking up on the angle iron. I drilled 7/16" holes on the bottom of the tube so the tube could slide about 18" to the left and be centered on the saw table when slid to the right. I then used my pneumatic rotary tool with a thin slitting abrasive blade to cut a long 7/16" wide long notch between the drilled holes. This slot is the sum of the distance between the two bolts plus the 18" of the slide. If you want the table to slide farther, make the slot longer. The hole on the left is drilled so when the slot hits the left bolt, the sliding table is even with the cast iron top of the saw. You can put flat washers on the bolts between the angle iron and tube to adjust the top perfectly with the saw cast iron top.
Now the little table was lowered over the two bolts looking up and the table slides left 18" and aligns with the table when stowed in rest position. The last photo shows a hole drilled through the table top and through the top of the square tube for access to the two bolts looking up. I drilled this hole in the bed of the far-right miter gauge slot. When the table is slid, the hole centers over the two bolts looking up. I screwed on two NyLok nuts shown in the last photo that anchors the little table to the saw. It can slide but can't lift off.
The photo with the colored arrows is a close-up of the sliding details. Red arrow highlights the bolt with lock washer holding the table bracket to the angle iron, white arrow shows I needed a single flat washer under the sliding tube to adjust my table height, green arrow shows the NyLok nut on the bolt capturing the tube, and the blue arrow shows one of the sheet metal screws holding the top to the tube.
Step 3: The Big Table
The big part of the table sizes itself from here on. It is as wide as the little table and long enough to clear the floor when folded down. It is constructed identical to the little table with a 2x4 lap-jointed frame, 3/4" MDF top and 1/4" Masonite topper. It is attached to the little table with a piano hinge.
For support legs on the outboard end of the table I welded up a set of 1" thin walled square tubing legs that attach with another piano hinge and fold under when the table is stowed. I welded nuts in the bottom of the legs for adjustable furniture feet that have felt pads. These feet slide effortlessly across my concrete floor.
As you can see I break all the rules of shop etiquette and use this table for gluing, painting, construction. drawing, etc. When the topper gets too crusty, all I have to do is replace it with a clean sheet and I am off and running again.
Also notice I arranged my saw near my built-in cabinets/miter saw station that allow me to rest the back end of bug sheet on it before feeding them through the saw. That cabinet is a version of one Norm Abram built in an episode of New Yankee Workshop. That is the topic of another Instructable! Also not the adjustable height, rolling support next to the saw top to help in-feed of big sheets. This is another New Yankee Workshop project that is indispensable.