Hi I'm Ding from Ding's Workshop Some time ago friends in my woodworking social group asked "If I want to make trims or decorative frames" "How do I make perfect 90 degree or 45 degree cuts with only a circular saw?" Today I will share with you a simple circular saw crosscut jig Actually, to make trims, baseboards, or crown molding A miter saw is most suitable and safe for the job but for folks who do not frequently woodwork a miter saw is indeed a big investment Here I assume that folks who need to make a crosscut jig do not have large cutting equipment like a table saw or a miter saw so today I'm making this jig using basic hand held tools and share with you my thought process of making this jig I will also share the mistakes I made and some fun facts about circular saws throughout the process so if you're someone who likes to fast forward youtube videos don't fast forward on this one let's first talk about the tools we need A circular saw for obvious reasons a straight edge I'm using a level a speed square a drill or an impact driver. one is enough, two is better and a few clamps first, we need to cut a straight edge when making a straight cut you need a known-good straight edge as a reference for example I'm using a level you can use a known-straight wood, metal strips, anything that's known-straight machined metal pieces can be good choices first I clamp down the board Note there's a mark on the circular saw's shoe this mark shows where your blade kerf is when the blade is 90 degress to the show if your blade is 45 degrees to the show then you need to look at this notch marked for 45 this line I drew might not be perfectly straight, but that's ok I just need a known-good straight edge and make sure it's secured now I can use this straight edge to make a straight cut here I want to share a fun fact about circular saw most tools such as drill, jig saw, are not differentiated by left and right hand but circular saw are differentiated by left hand saw and right hand saw put it simple if the blade is on the right side, it's a right hand saw suitable for people who are right handed and if the blade is on the left side, then it's a left handed saw now someone might ask hey Ding, wait a minute... if the saw blade is on the right and I hold the saw with my right hand when I'm making a cut I'll have to really reach my neck to see the saw blade this is actually a misconcept when you are using a circular saw (sidewinder) your eyes shouldn't really need to look at the blade as we know, circular saw is good for making straight cuts When you are cutting a straight line staring at the saw blade or the line is sort of irrelavent to the actual outcome of your cut what matters is making sure the circular saw's shoe is always agains the straight edge reference in other word, if the circular saw is moving in a straight line then your cut will be straight now someone else might say "I'm a right handed person" if my saw blade is on the left I can stare at both the straight edge and the saw blade, isn't this better? it's true you can stare at both straight edge and the saw blade but from my demonstration you can see that circular saw produces a lot of saw dust if I use my left hand and hold a right handed saw the blade will be on the inside of my body the saw dust will land on my body my fine beautiful long hair, and can easily go into my lungs also, from a safety stand point circular saw can have kick back when used wrong when kick back happens, it's a lot safer to have the blade on the outside of your body okay now I know this edge is straight, I'll make a mark this way I won't forget next step we need to use this straight edge and a speed square to make a 90 degree straight cut here's my known-good straight edge put the speed square here making a cut along the speed square will get me a 90 degree straight edge next we need to find board for the base the board has to be wider than the circular saw shoe my circular saw's shoe is 6.5 inches wide so if I find a board say...9 inches wide, then I'm good I found a scrap piece of wood this is half inch plywood one thing for this base piece is that, the short end has to be straight it'll make installation a lot easier the other 3 sides won't matter now I'll cut a straight line to one side so the max depth of my saw is 2.5 inches the board I'll use as base is half inch so this means I have maximum 2 inches of space between my bottom board and the the work surface but frankly speaking if you want to use circular saw and cut a straight perfectly 2 inch wide strip it will be difficult the reason is you will first need a straight edge as your reference and your reference has to be perfectly parallel with the straight edge of the board when you're using a straight edge for alignment it's almost impossible to get absolute perfect parallel formation to the edge rulers won't help as the ink on the marks varies and therefore it's really difficult to cut perfect dimensions and if you can't gaurantee your reference point then it's likely your cut will be some sort of a wedge as in, one end of the cut will be 2 inches wide the other end might be 2.1 or 1.9 so for simplicity, I'm using scrap from previous projects this is 2x2 actual dimension is about 1.5x1.5 it's pretty straight I'll use this okay so this was my board here I have a straight cut edge here's another straight cut edge and they're 90 degrees apart now i'll flip it over okay so here's a known-straight edge and my 2x2 is has straight surface right here I can let the board standing like this put the 2x2 face flat both pieces are on the same flat surface now I know these pieces are flush to each other and I can fasten them from behind using screws to make it more solid I'm adding some wood glue putting it here let it stand on a flat surface make sure two pieces are flush I can also check by using a flat surface make sure they're flush this step is very important as I want to make sure the 2x2's inner edge is parallel to the board's straight edge so that the 2x2 is perfect 90 degrees to the side checking the alignment using my speed square after making sure I have a good 90 I can fasten the 2x2 from behind using screws now we secured the front fence the rear piece is just there for the height the rear piece doesn't have to be well aligned there's no requirement on accuracy just need to make sure it's the same height as the front fence piece here I made a mistake the rear 2x2 was too long when I make a 45 degree cut my material will need to come in like this the long rear piece will block my material this tells us it's best to have your design validated before making also spend good time learning math and geometry next we'll install the botton piece for your saw on here if you recall, this edge was cut straight and this straight edge will be flush to the front edge here like this the rear doesn't matter, just make sure front is flush I cut the rear short just for cosmetics now it looks better adding some glue make sure the front is all flush checking with a flat surface make sure front is flush feel free to spend more time here to make sure they're well aligned if you have nailers it'll be easier you can shoot several nails here and be done with it but today I'm assuming you don't have nailers or many other tools I assume you only have a few hand held tools next step I put my saw on top and make sure the shoe of my saw is parallel with the front edge then i'll add pieces of wood on each side of the shoe so that I can ensure the circular saw has a straight movement for the wood piece I can install one screw, then do the alignment making sure front is parallel with the edge finding the right position and fasten the other side next step is to make a through cut on the base here I made a mistake before making the cut, I should've first opened up the observation opening if I cut first and THEN make the hole the cut line is in the middile, which makes drilling very difficult okay I made a cut and now increase my blade depth to just a little into the bottom board and make another cut this way I will know my blade's exact travel during a cut this way I will know my blade's exact travel during a cut well now I just look like an idiot there happened to be a screw in my cut path so when you're securing the 2x2s make sure you know where the screws are finally I'll make a hole so I can see the blade kerf easily and it makes it easy to see where I'll be making the cut as I previously mentioned, I should've made the hole first and then make the cut now let's see the problem I had when making a hole after the cut in this situation, I had to tilt my drill bit a little make sure it bits into the wood and then straighten up the drill from this hole I can easily see where my blade will travel this way when I put in my material I know this is where I should put my material at and my cut will be good when you have a jig like this you can make repetitive cuts easily first you need to clamp the jig on a surface here I used two clamps then you do your measurement, make a mark place your mark on where the blade kerf is at the end of the material, add a stop block here I used a scrap piece and clamped it down now I can ensure every cut will be the same dimension when I put in new material it'll hit the stop block this is how to make a simple circular saw crosscut jig I hope today's video is helpful to folks who don't have many tools I hope you like today's video. Let me know what you think in the comments and I hope you can subscribe to my channel I'm Ding from Ding's Workshop！See you next time!
