Ceiling-Mounted Adjustable Table Saw Guard
This guard for my table saw blade is constructed of clear polycarbonate so it provides plenty of protection, but it doesn’t restrict visibility of the blade or the surrounding area. It can also be easily raised and lowered to match the thickness of the workpiece, and it even folds to the side if I need to get it out of the way for a jig or tall workpiece. Most importantly, it has integrated dust collection to capture any dust coming off the top of the blade.
Many woodworkers consider the table saw to be the heart of their shop. It can be used to cut lumber, sheet goods and joinery, and for many other operations. Take a tour of many of these shops and you’ll likely see that the guard has been removed for various reasons. When I got my sliding table saw several years ago, I challenged myself to design a guard that worked for all of the operations that I perform on my saw. I didn’t want a guard that ended up in the corner of my shop collecting dust. I’ve successfully used my original guard for a few years, but recently made a few improvements.
Draw the Shape
Draw the outline of the guard to cover the blade at full height. The top of the guard needs to be flat to attach the dust collection port and the mounting brackets that attach to the supporting column. You could also use three straight lines instead and join the front, top and back pieces of polycarbonate without a curve between them.
A Matching Set
Plywood ribs hold the sides and top together. Both ribs need to be identical, so tape them together and sand the outside edge smooth. If you’re going to create three flats on the ribs, attach three separate pieces of polycarbonate to the guard. Bedrosian rounded the transition from the flat top to the curved front and back to make it easier to bend the polycarbonate used for the top of the guard.
Mark, Then Cut
Use a marking gauge to offset the outside shape so the ribs are about 1-3/8" wide after cutting at the band saw.
Flush Trim the Sides
The 6mm thick polycarbonate sides are screwed to the plywood ribs and then routed flush. If you countersink the screw holes, you can use either a template bit or a flush trim bit.
Drill, Then Cut
Cut a hole for dust collection in the top of the guard. Bedrosian uses a short section of 4" PVC pipe and drills starting holes before cutting the opening on his scroll saw. The opening needs to be near the back of the flat section on top of the guard so there is enough room towards the front to attach the support column.
Heat It to Bend It
Clamp temporary spacer blocks between the two sides so you can drill screw holes to fasten the polycarbonate to the plywood ribs. Secure the top section first before bending the polycarbonate over the front and back. Bedrosian uses a heat gun to soften the polycarbonate where it bends over the tight radius from the flat top to the gently curved front and back. Heat the polycarbonate evenly from side to side until it bends smoothly.
CA Glue and Brackets
Bedrosian uses CA glue and four angle brackets to secure a short piece of 4" PVC pipe to the top of the guard. This will connect to his dust collection hose. The angle brackets also help to secure the polycarbonate top to the plywood ribs.
Mark and Mount
Mark the mounting location overhead. With the guard in the correct location on the table saw, use a long straightedge to transfer the position to the ceiling. Bedrosian uses two pieces of plywood secured between the floor joists to hold the guard in place. Depending on your situation, you may need to add extra blocking between the floor joists to provide something solid on which to mount your guard.
One High Hinge
The upper part of the column is hinged so the guard can be folded out of the way. Bedrosian uses a clamp to hold the sections of tubing together as he marks the bolt holes. A U-bolt toggle clamp provides plenty of force when closed so the lower section of tubing is rigid.
Secure the Upper Section
The short upper section of 3" tubing is sandwiched between two pieces of plywood that are secured between the floor joists. Drill four bolt holes on each side of the tubing and then use a transfer punch to mark the corresponding holes in the plywood. Bedrosian uses blue tape to hold each nut to a wrench so he can get them inside the 3" tubing.
Bedrosian routed 1/8" wide grooves in 3/8" thick plywood to accept 1/8" thick UHMW strips. The plywood is mounted to the side faces of the 2" tubing to reduce friction as it slides inside the 3" tubing. Use a scrap of 3/8" plywood under the 2" tubing so the plywood sides are offset equally.
Add Some Pressure
Bolt a toggle clamp to the 3" tubing so that it presses against the 2" tubing to lock it in place.
Hang It High
The guard swings out of the way when not needed. Bedrosian uses a short section of chain fastened to the ceiling and hooks it to a bolt in the guard to hold it out of the way.
Spring for It
A spring helps to offset the weight of the guard so it doesn’t crash down when the locking clamp is released. The upper bolt holding the spring should be positioned so the guard floats a few inches above the table saw with the locking clamp released.
A Nice Brush
Add a 2" brush to help with dust collection. A brush on the offcut side of the blade works best. Here, Bedrosian put the brush on the right side of the blade because he has a sliding table saw. In a typical cabinet saw application, the best place for the brush would be on the left side of the blade. Use small mounting blocks with locking tabs on the side of the guard to hold the brush in place. A 1/8" pin is glued into the wood and inserted in a hole in the side of the guard to lock the brush in place. The same blocks hold the brush upside down when it’s not needed.
Start at the blade
The blade guard is made from clear polycarbonate which, unlike acrylic, is shatter-proof. I used 6mm thick for the sides and 3mm thick for the top. To save money, check with a local plastics supplier to see if they have off-cuts to sell. I got more than enough material to make the guard for $15. The sides and the top of the guard are joined together with a pair of Baltic birch plywood ribs – 1/2″ thick in my case, but 3/4″ would work just as well.
Before doing any cutting, decide on the size and shape of the guard that will work best for you. My table saw has a scoring blade in front of the main blade and I wanted both blades covered so my guard is fairly long. If you decide to make yours shorter, just make sure the flat section on top is large enough for both your dust collection fitting and the aluminum mounting brackets that secure the guard to the column.
The guard should be at least 2″ wide, maybe more, depending on the size of your dust port. You want enough width to fully cover your blade when it’s at maximum height and tilted to 45°. My guard is 4-3/4″ wide to fit my 4″ dust collector hose.
I used a single piece of polycarbonate for the top, and heated that piece to bend at the curves, but you could also design this with three straight lines and use flat straight pieces of polycarbonate for the top.
Make the ribs
Rip the plywood ribs to the correct height and use your band saw or jigsaw to cut the curves on the front and back. Smooth the curves with your sander and transfer the outside shape to form the inside of the rib. Mark the outer face of each rib so you know which side to attach the polycarbonate.
You’re now ready to cut the 6mm thick sides. If you haven’t used polycarbonate before, you’ll be pleased at how easily it cuts. It can be cut with your table saw, band saw or even a scroll saw, and you won’t need special drill bits or router bits. It’s best to leave the protective film on while you mark for any cutting or drilling. Align the bottom edge of the polycarbonate with the bottom of the rib and trace the outline before cutting both sides slightly oversize. I did this on my band saw using a 6 tpi blade. As with the ribs, mark the outside faces before you drill and countersink four holes to secure the polycarbonate to the ribs with flat head screws. Use your router with either a pattern bit or a flush trim bit to rout the polycarbonate flush to the ribs.
Top it off
The sides of the guard are held in place by a single piece of 3mm thick polycarbonate that starts at the back of the guard and curves over the flat top section and down the front. Cut the polycarbonate to the outside width of the guard; 4-3/4″ in my case. Before bending the polycarbonate to the shape of the ribs, cut an opening for the dust collection fitting. I used a short piece of 4″ PVC pipe which I traced around the inside and cut the opening on my scroll saw.
Cut temporary spacer blocks to the inside width of the guard and use them to clamp the two sides in place. Align the 3mm polycarbonate on the top flat section and secure it near the front with a pair of screws into the plywood ribs. An automatic center punch works well and you can then drill the pilot hole through both the polycarbonate and into the plywood before enlarging the hole in the polycarbonate. This ensures perfectly aligned holes for the pan head screws. Staying on the top flat section, plan ahead to use the holes for your dust collection fitting for the screws near the back. I used four small right-angle brackets with my PVC pipe, and I lined them up to be in the middle of the plywood ribs. Drive these screws in without the dust collector fitting, which you’ll add once the top is bent over the front and back.
Polycarbonate will bend without breaking, but it takes a lot of force to get it tight to the ribs where the top transitions to the front and back. To help with this, I used my heat gun to soften the polycarbonate to make this relatively sharp bend. After that, the polycarbonate should easily bend along the gentle curve on the front and the back without heat. Drive screws in where needed to hold the top securely to the ribs. You can now add the dust collector fitting. I used a bead of CA glue to hold the PVC pipe to the top and further secured it with right angle brackets.
Support the guard
With the blade guard complete, turn your attention to the support column. Your installation may differ from mine, depending on the height and type of your ceiling. For my 7-1/2′ high basement shop, I used a 3′ long piece of 3″ square aluminum tubing mounted into the ceiling, and a 2′ long piece of 2″ square aluminum tubing fastened to the top of the guard. The smaller tubing fits inside the larger tubing and can be retracted or extended depending on the thickness of the workpiece. Aluminum can be cut with a carbide blade on your table saw or chop saw; be careful to hold the metal securely to prevent any kickback. Alternatively, the few cuts that are needed can be done with a hack saw.
My shop has a drop ceiling so I was able to remove some of the ceiling tiles and fasten support boards for the guard between the floor joists. To determine the correct position, set the guard over the blade so that it will cover your widest dado set as well as your blade tilted to 45°. Mark where the 2″ tubing will attach to the top of the guard and use a long level to extend that location to the ceiling; this is where you want to mount the 3″ tubing. I used two pieces of 3/4″ Baltic birch plywood and secured them to the floor joists with wooden cleats. The plywood pieces should be 3″ apart so the upper tubing fits snugly between them.
One of the features of this guard is that it can easily be folded out of the way to allow cutting tall workpieces. This is done by cutting off the top 7″ of the 3″ tubing and attaching the pieces together with a hinge and a U-bolt-style toggle clamp. Use a 3″ wide hinge with a non-removable pin and bolt it to the left or the right side of the tubing, depending on which way you want the guard to fold.
The 2″ tubing needs to slide up and down inside the 3″ tubing to allow the guard height to be adjusted. The inside dimension of the 3″ tubing is 3/4″ larger than the 2″ tubing, so I made up most of the difference with 3/8″ thick Baltic birch plywood attached to opposite faces of the 2″ tubing. My original guard had the plywood cut to width to fit precisely inside the 3″ tubing which worked fine. With this improved guard, I wanted to reduce the friction of the plywood edges rubbing against the tubing so I added UHMW strips. If you choose to do the same, cut the plywood 2-3/8″ wide and 21″ long and then rout 1/8″ thick grooves 3/16″ deep on the long edges of both pieces. Cut 3/8″ wide strips of 1/8″ thick UHMW and insert them into these grooves to get the desired width of 2-3/4″. Use a hand plane to shave down the UHMW until each board glides smoothly inside the 3″ tubing before fastening them to the 2″ tubing.
Bolt a toggle clamp near the bottom of the 3″ tubing so when it’s engaged it applies enough pressure to the 2″ tubing to keep it from moving. Ensure the 2″ tubing slides up and down easily. There should be a bit of play side-to-side since the plywood is slightly less than 3/8″ thick, but there should be minimal front-to-back play with the UHMW strips. You’re now ready to bolt the 3″ tubing to the plywood that you previously mounted overhead.
Secure the guard to the 2″ tubing with 1″ by 1″ aluminum angle stock cut to the same width as your guard. Bolt the angle stock to the tubing and use screws through the 3mm polycarbonate into the plywood ribs. Drill a hole above the angle mounting bracket all the way through the 2″ tubing from front to back. Fasten a bolt in the front hole with about 1″ sticking out the front. A short section of chain attached to the ceiling will hook over this bolt to hold the guard when it’s folded out of the way. The bolt in the rear hole should stick out far enough to attach a spring that counteracts some of the weight of the guard. The other end of the spring is attached to a bolt in the 3″ tubing.
Sweep up the dust
My original guard had outstanding dust collection for most cuts. The one exception was making cuts where the blade was only skimming the edge of the wood. As an example, when ripping away 1/16″ from the side of a long board, most of the sawdust was ejected from the side of the blade and wasn’t trapped by the guard. To help with this, I added a removable brush that attaches to the side of the guard and extends around to the front as well. The brush fits snuggly into a groove cut into a strip of maple clamped to the side of the guard. The same clamps hold the brush upside down when it’s not required.