How To Make A Wooden Bar Clamp Clamps & Vises
At this point, I’ve lost count of how many different wooden clamps I’ve designed and made over the years. Some were successes and others were… well, not so successful. But they were all part of the learning process. Without those earlier versions and the knowledge I picked up from building and using them, it’s doubtful that I could present today what I think is the best I’ve done so far. It takes everything that I learned from the ones before, and in one way or another, applies it to this design. The things that work and the things that don’t.
As with most of what I do, it started with an idea that I roughly sketched on paper, then refined a bit in SketchUp, before building a prototype. While building the prototype, I thought up ways to improve it further and tried those out before committing to the final design. That’s the upside to making a prototype and whittling away at the design to refine it; the downside is that it takes a lot longer.
To get started I cut the bars for six new clamps from ash to the right size and planed them smooth:
Ash is a good choice for the bar – it’s a very strong, stiff hardwood that will resist bending. The board I cut these from (a single 4/4 x 6″ x 8′) was straight grained and defect free, so these bars should withstand a lot of use without breaking. At the $2.80 per board-foot I paid for the ash from my local supplier, the cost for the bars $11.20. Not bad for six clamps.
As for other wood types, any harder species of hardwood (maple, oak, hickory, for example) will work well. I would avoid soft woods since they generally don’t have enough stiffness to resist the bending force, and the saw tooth notches that will be cut into the bar may wear out prematurely.
Speaking of the saw tooth notches, I made a fairly simple jig to do this with my trim router. The first step was to cut a scrap piece of wood to a 10 degree slope on each end. I used a wide stop clamped to my miter saw and made the cut with the saw set to 10 degrees:
With the jig assembled, I set it up to make the first notch. To do that, the guide bar has to be cut down as shown here to sit on top of the bar:
I used my sanding file to do that. This bar is only used for the first notch and will be replaced with one that hasn’t been cut down for the remaining notch cuts.
Here’s the first one. These do not have to be deep for the clamp to grip. That’s one of the things I learned from other builds:
Ideally, the notch will be 1/16″ deep at its lowest point, and no deeper. To make the cut, my trim router was set up with a 1/2″ straight bit and a 5/8″ guide bushing to ride in the jig.
For the rest of the cuts, the narrow bar sits down into the previous notch and that sets the distance for the next one. To change the spacing, all you need to do is change the width of the narrow bar and the depth of cut on the router:
With the bars done, I moved on to making the two parts that will be the fixed jaw. I decided to make these from cherry for some variety in the look, but ash could have been used for this as well. The two halves of the fixed jaw fit around the bar and to do that, I made a series of cuts on the table saw using my mini table saw sled. I made a sample first to make sure the fit was perfect, and that’s what I’m doing here:
Looks good to me!
Some don’t see the value in making their own clamps, but I would strongly disagree. If you are just starting out, it not only gives you a capable tool that you may use for years, but it also gives you much needed experience making accurate cuts to create the joinery that you will later use for more “important” projects, like furniture.
With the sample done and fitting well, I could cut out the parts and then glue them to the ends of the bars:
I used homemade clamps to clamp the clamp – just scraps of 1/2″ plywood and 3″ screws. An alternate way to do this would be to just screw these parts together right on the bar. The screws will clamp the parts and also add some strength to the joints.
To illustrate this, I did it with one of my bars that was already glued up:
I located the screws offset to each other as shown, and drilled a pilot hole and countersink for the #8 x 1-1/4″ screws I used. Best to line up the parts and drill the pilot holes and countersinks before adding the glue. That will keep the parts from slipping around and ensure better accuracy.
All six of mine after the glue has dried and sanded smooth:
I started work on the moving jaw next, by cutting out the parts for the clamp pad. This is “L” shaped and made from two pieces of ash and joined with a bridle joint. The first cuts were on the vertical part. Note the counterbore for the end of the lead screw:
To make these cuts accurately, I quickly made a simple guide that fits over my table saw fence:
This jig allowed me to hold the parts while making the cuts into the ends to form one half of the bridle joint:
I then cut out the other part, the bottom of the “L”:
Once again I made samples before making any of these cuts in the real parts. A tight fit is important for maximum strength in this joint.
I used polyurethane construction adhesive to glue these. It has longer open time and much better gap filling properties than regular wood glue. It also doesn’t need to be clamped for a nice, tight fitting joint like this:
Next up, is probably the trickiest part to make for these clamps. I call it the screw block, since it houses the t-nut that the lead screw threads into. I did the basic shaping on it before drilling the counterbore for the t-nut:
Then drilled the hole through for the lead screw and installed the t-nut. It’s important to always mark and drill holes for the tangs on these t-nuts before driving them in, as the tangs will split the wood in a small part like this. To hold it in there so that it can’t back out, I drove a small screw that lips over the flange:
I then cut the latch plates from 1/8″ aluminum using my bigger table saw sled. I put a metal cutting blade in my saw for this. Even though a regular carbide tooth woodworking blade will cut this aluminum, it’s not something I’d recommend. The hook angle on the teeth is too aggressive, especially for small parts like this. Also the use of a sled like I did here is highly recommended. Aluminum sticks to the teeth of the blade, making these smaller parts potentially lethal projectiles if thrown back after jamming between the blade and the fence:
And remember, if the caution is coming from me, it can be counted on – I don’t exaggerate risks.
The plate needs a hole so that it can be screwed onto the screw block:
And the end of the plate needs to match the angle on the wooden block. On mine, I cut both at the same time with my miter saw set to 10 degrees. I used a simple fixture clamped onto the saw to hold the parts exactly while making the cut. This can be seen in the video at the bottom of this article.
One other thing to do with the plate is to file a slight back bevel so that it will match the notch cut into the bar better:
This is how it should look with the screw block and clamp pad in place on the bar:
The latch plate fits down into the saw tooth notch perfectly. If you are making this and find that yours doesn’t fit like this, you can always make the bottom part of the clamp pad thinner to adjust it. Likewise, if it’s too long, you can always shorten the latch plate and screw block.
Time to make the other very important part of the moving jaw, the bottom block with the wooden spring:
I used ash for the block and maple for the spring. Maple is more resilient than either ash or cherry, so it’s a better choice for this. The spring must be made from very straight grained wood, otherwise it may break. It is possible to replace the spring in a finished clamp, but it’s not an easy task. I used epoxy to glue the spring to the block for maximum strength. Regular wood glue will also work for this.
****NOTE: There is a missing dimension on the plan for the bottom block:
My handles were made from cherry, but this is a part that you can use softwood for, if you prefer. A 3/8″ hole needs to be drilled into the end for the threaded rod lead screw, and I’m holding the part vertical in my drill press vise:
I then finished the shaping, mostly with my belt sander platform:
The threaded rods are cut to length and I ground a flat spot near the end that will key into the handle when glued in:
The rod needs to stick out 4″ with 2″ glued into the handle:
I made the retainers from ash:
I drilled the holes with a 3/8″ brad point bit, then reamed them out slightly bigger using a step drill.
Assembly of the moving jaw starts by threading the lead screw into the screw block, then slipping on the retainer before gluing the nut onto the end:
I used epoxy and made sure that the parts were clean before gluing the nut in place at the end of the lead screw. There are other ways to secure the nut, like slightly flattening the end of the rod for an interference fit, or drilling a hole through for a pin.
Next, the clamp pad is glued to the retainer and clamped. Before doing that, the 3/16″ fender washer was put inside the counterbore and a small amount of vaseline put on the end of the lead screw for lubrication:
Waiting for glue to dry makes up for a lot of the total time it takes to build these clamps, so it’s sensible to schedule other operations while that’s happening. Here I cut and planed the sides of the moving jaw while waiting for the glue on the retainer to dry:
I made these from cherry again, and cut them to the right length on my miter saw with the stop block set to 5″.
These can be glued and clamped, but I don’t have enough clamps on hand to do six of these at a time. So instead I drilled the countersinks before drilling the pilot holes for the #6 screws I used for this:
Just four strategically placed are enough.
I used polyurethane construction adhesive again and made sure the glue wasn’t too close to the edge to avoid have it squeeze out and interfere with the lower clamp pad:
Note the screw holes. You definitely need to drill the pilot holes for these screws before you put the glue on. Otherwise, the parts will slide all over the place.
And then all that’s left is to drive in the screws and wait for the glue to dry completely before using them:
I went the extra distance and gave mine two coats of water based poly to keep any glue squeeze out from seriously sticking, and to keep these clamps looking sharp for years to come:
I had to take them outdoors to get a good picture, which can be interesting in the middle of winter.
If you would like to build these for your shop, there are plans available:
I made a video covering this project:
In this video, I make the jig for cutting the saw tooth notches in the bar: