before we get started i wanted to mention something as a courtesy to some of our viewers a while back we did a review of the 3m professional sanders and they immediately sold out because so many of you wanted to get one well they are back in stock and they are 20 off which is a significant savings that is not going to last there's a big waiting list on these they're that popular and they're that hard to get at this point because it's a brand new thing so this chance is going to be gone shortly and i don't want any more of you upset like you were at me last time i don't control any of that but i will put a link below i'll pin it to the top of the comments so if you're interested go ahead and use it now let's talk about this contraption one of the most important skills a woodworker can learn is how to make effective jigs far too often i see woodworkers fall into the trap of thinking jigs are only for when you need to make a hundred of the same thing and if it's just a handful of cuts it's better to make them individually rather than wasting the extra time to make a jig that's not true at all a jig can serve as a guide to make any project faster safer or more accurate no matter the project size or complexity this workbench is a perfect example it's a relatively inexpensive 2×4 frame that can be topped with plywood to serve multiple purposes in the workshop i love these because the simplicity of the design makes them not only easy to build but really versatile the key is the lap joint construction these joints are very strong and they're flush which give the legs and the stretchers a more attractive appearance and it makes it possible to set multiple benches right next to each other and connect them together to make a solid assembly of benches eventually when i have the project plans finished we'll make a video about how i made this modular workshop that fits along one wall of a typical garage using this type of frame construction but today i want to focus on the jig we built to cut the lap joints specifically i want to show you our process for designing jigs because you can then use those tips to make your own projects and become a better woodworker as i said the right jigs can be the key to a successful project but quite often you have to design and build the jig yourself to solve a specific problem on a specific project on this project we had to cut a lot of lap joints some on the ends of the work pieces and others in the center we knew they all had to be precisely the same so the project parts could be all batched out together with the confidence that they would fit together properly when assembly time came we decided the best tool for the job was a router but we needed a way to guide the router while confining the cutting area to the precise width and depth that the joints required and which would work with project parts of different lengths and orientations we started by nailing some scraps of plywood to a base this created a channel for a 2×4 work piece to slide into the two plywood rails were equal in thickness to the work pieces and on top some scraps were added to create fences to guide the router pneumatic nailers are ideal for jig construction because you can fasten parts in place quickly and semi-temporarily without the shifting that can occur when you drive in screws this spacer is exactly as wide as the lap joints had to be which is of course equal to the three and a quarter inch milled width of my 2×4 project parts using spacers is a much more reliable way to make a jig like this than just measuring and marking as you can see the fit is very precise and the work pieces will slide in and out of the jig easily the idea was to use a flush trim router bit the bearing would ride against the two upper fences to cut the joint to that specific width but as often happens this jig began to evolve almost immediately as we saw ways to improve it for one thing we found that while the pneumatic nailer was ideal for initial assembly once the project parts were tacked in place we could add some screws without them shifting and this would give it added strength so nothing would move out of alignment during heavy use we also realized that cutting a channel in the front rail could allow the dust to come out of the jig so it didn't all get packed up and jammed inside during each cut still the straight cutters on that flush trim bit just seemed to struggle to clear the dust effectively you can hear the pulsating sound it's making as it tries to hog out all that wood [Music] an upcut spiral bit is much better suited to this task because it lifts the dust up and out of the cut so the bit can cut more efficiently notice the difference in the sound this bit will make the job much easier and it will last a lot longer but it has no attached bearing to guide it so the jig again had to evolve with the addition of some strips of plywood to the upper fences now the edges of the router plate will run against these strips to confine the cut to that precise required width we also trimmed the ends of the front rails off so clamps could be applied quickly and easily to secure the work piece to the rear fence and it worked really well the joint seemed to be fitting together perfectly and we could have just called the jig done at this point but the dust was still annoying it added an extra step to each cut because it had to be sucked out before a new work piece was slid into the jig and it made a big mess on my floor yes my shop is carpeted i made a video about it in the past i'll link to that video below if you haven't seen it basically it's easy on the feet it's warm and quiet and it's no more difficult to vacuum than a cement floor is to sweep but that doesn't mean i want dust flying all over the place so we made a dust shroud out of cardboard with a hole for the shop vacuum hose at first the results were mixed about a third of the dust seemed to still escape but after some tweaks it proved quite effective virtually all the dust was sucked out of the joint and there was no need to manually suck it out between cuts it worked so well that we eventually made a more permanent wooden version attached right to the jig so that this jig could be saved and reused many times in the future and there it is the final jig took about a half hour to build and modify to our needs but once it was finished it reduced the overall time to cut lap joints by far more than that 30 minutes and the results were consistent with no errors or miscuts and that's the lesson of this video we weren't mass producing benches but building the right jig for the job proved worth it even for a single bench and i hope this look into our process helps you devise your own jigs for your future projects but before you go i have one more thing you have to see woodworking is about squares fences must be square blades must be square tables must be adjusted so cuts are made square our corners must be square our edges must be square even
