i like interesting joinery the right joint can be super strong but it can also be beautiful in and of itself i think this is such a joint i call it the triple castle joint if i was a gamer i might call it the triforce joint i have no idea who first came up with it but i love the complexity of it at least the perceived complexity because while this joint looks to be a puzzle of mortises and tenons that would be frustratingly difficult to cut it's made from three identical pieces each containing just four straight cuts i first saw this joint when a viewer sent me a link to the three by three custom channel evidently she saw the joint on pinterest and what i can only guess is some type of bed or table she found it so interesting that she figured out how to cut it on her table saw i'll link to her video below if you want to try it the way she did it's a really good video the viewer who pointed me to that video asked how i might approach this and honestly i'd probably cut it with a table saw just like she did but that's already been done so i'm going to try and make this a little more interesting by cutting it by hand and while i do i'll show you not only the secrets of this clever joint but i'll give you some hand sawing tips that you can use for all sorts of other projects if you want to improve your hand sawing skills pay close attention for the next few minutes since this is just a demo i'm using some relatively small pieces of walnut but this can be done to any scale including large beams as long as you follow two rules all three pieces must be the same size not including their length of course and the width of each piece must be one and a half times its thickness here the thickness is 36 millimeters yes calculating ratios like this is an example of where millimeters are better than inches and the width is 54 millimeters which is one and a half times its thickness now this ratio is critical for the joint to work but it also makes it really simple to lay out that's good because the layout looks anything but simple you can see here all the waste that has to be removed but it's all based upon the 1.5 to 1 ratio that means you can use the work pieces themselves as marking gauges and skip virtually all the measurements i've already marked mine but here's how i did it with the work piece laying on its edge all the front and back faces are marked with a pencil with the work piece turned to lay flat a second line is scribed on all the front faces and both the edges with a work piece still laying flat all the fronts are marked first while laying on one edge then flipped end for end to the other edge this essentially divides the faces in two thirds and the same process is repeated on both the front and back faces of all the work pieces a similar process is used to mark the end grain of all the work pieces once again dividing it into thirds now i'm using a combination square to draw right down the center of the end grain from edge to edge turning those three sections into the six finally i use the same square setting to bisect both edges of all the work pieces once again you can see i've colored in the waste areas that have to be removed it looks complicated but it's really not just re-watch the last few seconds copying what i did and you'll be fine if you insist on a dimension drawing here's one based upon work pieces that are an inch and a half thick and two and a quarter wide that same 1.5 to 1 ratio of course if your work pieces are any larger or smaller than these you'll have to recalculate these measurements and that can introduce air that's why it's always best to use the work pieces themselves as a gauge keeping that principle in mind to use your work pieces as much as possible instead of measuring will save you a lot of frustration in this craft no matter what you're making another excellent tip that will help you in any number of projects is to cut a shoulder to guide your hand saw this is done by using a knife or a marking gauge to scribe over your lines then following up with the chisel on the waist side of those lines the chisel removes a little wedge of material and leaves behind a groove that your saw blade can drop inside and a shoulder to guide it since the saw will naturally want to follow the path of least resistance these shoulders will make it much easier to create nice straight cuts you'll see what i mean as i make my first cut as i said despite all these lines there are only four cuts to be made the first one is right down the center of the end grain i angle the work piece so i can see the line on the edge facing me and the one across the end grain i drop the blade into that chiseled groove where it naturally fits against the shoulder right on my line as i'm cutting i'm working back and forth taking light strokes which follow that line down the edge then across the end grain once i've deepened the groove a bit more i can speed up the cut a little bit letting the curve start to guide the saw again down the edge and back across the end grain once i've connected my two opposite corners at this angle i can reverse the work piece in the vise and repeat the same process starting at the other corner there's no rush take your time and don't grip the handle too hard just relax and let the kerf guide the saw as you advance it deeper and deeper finally i set the work piece straight in the vise and i cut downward removing the triangle of waste that remains inside this finishing cut practically steers itself just don't cut past your baselines with the first cut finished i can turn the work piece 90 degrees in the vise and repeat the exact same process for the other two lines i scribed on the end grain this is a japanese ryoba saw which is a perfect saw for this type of joinery due to the ripped teeth along one edge and because there's no spine to impede how deep i can cut it's not an expensive saw at all and i think every shop should have one of these i'll put a link below to the one i use if you want to check it out one more cut this time on the face of the worst piece you'll notice that i'm using a different saw now i switched for two reasons first this is a cross cut saw and the rip filed teeth on the ryoba aren't ideal for cutting across the grain of course a ryoba saw does feature cross-cut teeth on the opposite side of the blade which is one of the reasons why it's so versatile however this saw which is called a dazuki features a thinner blade that i find even more precise however its spine limits the depth of the cut that's possible and the teeth aren't ground for ripping through end grain now i didn't count this next step as one of the four cuts i said this joint required because it's not absolutely necessary i'm just doing it to get rid of the bulk of the waste in the middle to make my chisel work easier it's a convenience really you could just chop all of this out with the chisel alone as i do use the chisel you can see how those shoulders i previously establ
