Cutting Tool Tips

Hi. Today, we're going to be talking about cutting tools. Cutting tools come in three basic varieties. Knives, saws, files. There are lots of variations in how those appear but those are the three basic types. If we start talking about knives, this is one of the most common, a hobby knife. You probably use it for all kinds of kit assembly. Lots of other work. They're very useful for cutting small strip wood. If you're making small cuts, they work quite well. One of the most useful, if you're working with styrene, and you're probably familiar with the scribe and snap. All you need is a simple scribe and then you snap cleanly. You can reassemble that and put glue in and it's almost invisible. As you can see one of the necessary parts of knives, any cutting tool, but particularly knives, is you want something underneath them, so you don't dull the blade. This is what's called a self healing mat. They're sort of soft, somewhat flexible. At least up to a certain point, you can slice across them and that cut will heal up. This is actually designed as a cutting board for kitchens. They're available in kitchen stores. They're quite cheap. They don't heal, as you can see, but you can use them up, glue on them and then toss them away when you're done. You can obviously use a wood surface as well. Anything, so that you don't dull that blade. The other thing knives need is a guide. Where you use a square. This particular square is a thin based unit. Most are, if you buy a machine, a square, about a half inch thick. That's awfully thick for most of our materials and it's nice to have this thinner one. Micro-Mark and others sell this one. I got this one from Micro-Mark. It should be noted that the limitations of knives, obviously are, is that as you get to thicker and thicker, I cut off a little piece of this but if I'm trying to cut through this whole piece of wood, I start to really work hard to be able to get through it. I can make a reasonably decent cut but it's a lot of effort. There are tools available to do that job for me this one uses a single edged razor blade. This is the chopper from Northwest Short Line. It comes in a few varieties. It has a built in angle and stop so that I can repeat cuts. Again, a useful, useful idea. I can measure my length, cut. With the leather, it's a lot easier cut, but even with this, as you may be able see, there's a slight angle to the cut as it comes through the wood. It's not perfectly squared and as you get to larger and larger dimensions, even this tool gets difficult. It's about, at that point, we'd want to move over to a saw and different kinds of orientation. Before we leave knives behind though, I'll talk about a couple other kinds of knives. We may not think of them as such but scissors are really just a knife and they have their place as well. These are precision sheers. They're useful, for example, if you have an etched brass kit and if all you're doing is snipping an etched brass piece off a sprue or something, that little short blade works just fine but we often forget that things like a regular pair of scissors are perfectly capable of cutting at least thin metal as well and so, if you have a much longer cut to make you should be willing to at least recognize the usefulness of scissors. Obviously one of the disadvantages here, at least if this is the piece you want, the little thin piece, is that scissors do tend to make it curl up but it's not difficult to straighten that back out and if this is the part you want, you're just fine. Obviously knife type tools have their limitations. As you get to thicker materials, harder materials, they become less and less useful and you want to move to other ways of cutting, the most obvious one being saws. When we have materials that are not suitable to being cut with a knife, either because they're like, this is a cast piece of plastic, I can't scribe and snap it. It doesn't work like the sheet plastic, so I'm going to need to cut it with a saw of some sort or in this case, a three-dimensional, this chimney. Obviously I can't cut it with a knife so I'm going to need to saw it. I can free hand that, but not getting a good precision cut, so I almost always want to use some sort of guide. In this case, a miter box. This is a full size miter box. In this case, I have a hacksaw in it. They also make back saws, which are essentially a larger version of the hobby, or what we call a razor saw, that are used for cutting. The hacksaw is good for most model work because it's a fine tooth blade. Almost all miter boxes, are almost all built with a lip, as is this little hobby one that's designed to fit against the edge of your table and that secures it in position, so you can cut against it. It has 90 degree bends and a 45 degree bend. Sometimes you find ones with a 30:60 cut. With a object like this that isn't a uniform dimension, one end to the other, if I were to simply put it in here, like that, I would be off counter angle on two directions so I can shim it up. There's a thicker piece of wood for the base, as long as it's thicker than that cap, I'm good that way and then I can tuck this behind it, likewise and get my cut. So once I have it shimmed, I can put it in here, clamp it in with my fingers. In this case, I'm trying to make that 45 degree cut and say I'm working towards putting it on, mounting it on a roof and I put it in here and I begin my cut. The razor blade is a very fine blade, so usually it starts just fine and I get my nice clean, precision cut at the angle I wanted. If I have a piece that's too big for my hobby miter saw, or which is, I can either move to a larger miter saw or choose to go to a power tool. I have a hobby band saw that I like to use for larger parts and different materials. This is a small hobby band saw. This one's from Inland Tool Company. It's one of the smaller ones available. There are also bench top saws made by Delta and Makita and most of the other brands out there. They're readily available at almost any hardware type store. This one is, was designed originally for the stain glass hobbyists. One of its blades is this abrasive blade but it also comes with regular metal tooth blades and wood blades. The abrasive blade works just fine, even for plastics. It has variable speed, which is good for working with plastics because you don't want them to melt at high speed. I've marked the line across here. You can see I've left just a little bit outside my line. I'll clean that up with a file. We'll talk about files in a few moments but you almost always want to cut just outside, whatever your line is and do your final cleanup. There are guides for these saws and for the the bench top ones that will help guide, but free handing, as long as you're going slow and careful. One of the reasons I like the saw on the abrasive blade is that the abrasive blade is good for cutting things like plaster. Again, it was designed for that. Plaster can be cut with a regular saw but it dulls blades very, very quickly. The other major type of cutting tool is files. Files come in many sizes, different shapes. They also come in different, they're ground different ways. This diamond pattern, where the cuts are going across each other, is called a bastard file. This is a very coarse one. It's also pretty old, but I find it still useful, particularly for doing rough work on wood and other such things. For most of my uses, I prefer what's called a mill file which has a single set of cuts running across it on both sides. Usually the edges may be blank or they may also be a cutting surface. This one has a cutting surface on one edge and is blank on the other. As you can see, when you cut, when you use a file, one of the things it can do, is what's called loading up. In this case, that's from using it on plaster but it happens whether you're using it on plastic, brass, white metal. Any file will eventually load up and that's what this tool is for. It's a wire brush, very much like your grill brush. In the absence of anything else, you could probably try using a grill brush, short, stiff things. As with any other tool, you keep it clean. It'll cut sharp, give you a nice clean edge. So anytime you're working with materials, you want to keep your files nice and clean. When you're using a file, you can freehand like that and that works fine for some things, but particularly if you're working with harder materials, this is a brass bolster casting. Being able to clamp it. This is a simple little bench clamp that has a sprue coming off that needs to be removed. Start gently until you get a flat surface, so you're not catching. It helps if you hold one end, both ends of your file. You can check your work, make sure you're holding square. So again, use of clamps to hold material while you file, especially helps you get a nice square clean surface, whether it's a bench vice like this or you can use a pair of pliers or vice grips to hold it. Somme other handheld clamps will make sure that you get a better precise finish. Another kind of file, in essence, is an abrasive tool. In this case, in a motor tool. They come in very handy for lots of different purposes. When we're laying track, flex tracker handling, we may often use a rail nipper to cut rail to length but once it's installed, periodically for wiring and other purposes, we need to gap our rail. This is a fiberglass reinforced cut-off disc. This one's actually worn down a fair amount. They're a bit larger to start with. They are very durable, hard to break which makes them very good. On the other hand, they're relatively thick. This is about 45 thousandths of an inch thick, which is okay but that may be a bigger gap than you'd like to have in your rail. If you get a regular dremel tool, you'll get this kind of an abrasive disc. It's very thin. 25 thousandsths, 22 but, on the other hand, it breaks very easily. A more recent option. This is a diamond coated steel disc. Works very much like that abrasive blade and the band saw, and it's only about 25 thousandsths, so it's a good option for slicing your rail as well. This is a 90 degree tool attached to the end of my dremel. Again, it's available from, Dremel makes one. This is actually one from Micro-Mark. If you have a regular dremel tool and you try to come in, you end up making a rather angled cut. I like this one 'cause then I'm able to get a much squarer cut. Now I've got my gap in my rail for electrical isolation. Another use for cut-off discs is cutting hard wire. If you've ever tried to cut it with a regular set of diagonal cutters, or that, you'll know you pretty quickly put big dents in your diagonal cutters. Not something you want to do. Again, the cut-off disc works very well for this. You should probably clamp the wire before cutting. Another good option for cutting wire is this. It's a hard wire cutter. You'll notice it's a very thick, not a sharp blade and even with this very heavy 45 thousandths wire, it cuts quite easily. It also shoots it across the room but that's a very good option. Won't dent. Highly recommend it. As we finish off talking about grinding filing tools. I should also mention the use of needle files. These are probably familiar to most people in modeling. Very useful in cleaning up small castings. All that sort of thing. They too get loaded up. You need to clean them. You can use the same file card I used on the larger files, to clean up those files. The final saw I'm going to look at today is this table saw. Many modelers tend to think in terms of modelers' tools and therefore small tools, like the band saw that we used earlier and there certainly are small table saws made for hobbyists and those are very useful and the jigs I'm going to show you will certainly work on those saws as well. However, there's much to be said for having full-size tools as well. The obvious use of a table saw for building bench work and that sort of thing, but they can also be very useful for precision modeling work as well. This is a 40 tooth blade, standard blade for this kind of table saw. This is what it's called a veneer blade. It's an 80 tooth blade. It's also ground, so it's much thinner, this way, compared to the curve you'd get from the full size blade. So this makes only about a 16th inch curve. This cuts out close to an eighth inch material. You can use this if you're going to be cutting. Not just cross cuts, but if you were to make your own strip wood. That sort of thing. You'll notice my saw's unplugged. Anytime you're adjusting a table saw, that's a wise thing. Again, you can say, I already have an 80 tooth blade mounted in here, ready for my cuts. I'm using a standard top in here. The insert, which for my cross cut, saw cuts that I'm going to be making here, are just fine. If I were actually cutting strip wood, I'd want something that was in tighter. You'll also notice, of course, that I don't have the big blade guard on here. As with many minor cuts, the blade guard isn't useful for that. That's in the instructions as well. Obviously, any time you don't have a guard on a blade, it's extremely dangerous. You want to be very cautious. Any time you touch your blade, your hand to it, it can go right through it. Many tools have open blades. The band saw among others. So this is not unknown but you need to be conscious of it. One of the reasons for using jigs is for making angled cuts. These are some... I was making a tunnel lining that used this arched design and each one of these cuts has to be made at a 15 degree angle. Now we saw with the miter box that it has some pre-set angles. I could make the little chop thing. I could adjust angles and eventually maybe get a 15 degree angle in there, but this would be big material to try to cut through on that chop. I wouldn't get a square cut. Lots of reasons and especially when making lots of these, like if I'm lining a whole tunnel. The jigs I have here, and I'm going to show, were for, this was a project of making a bunch of roof trusses which had to have many precision cuts. You can see, perhaps this piece, a single angle on this end. This end actually has one angle cutting across and then another angle this way. So making all those cuts precisely requires a good jig, a way to hold things. If you saw a professional furniture shop type table saw, you'd see that the whole side of the table, on this side of the blade, actually slides past the blade. If I angle my cross-cut blade and try to just cut through and if you've ever done that, you know that it has a tendency to try to drag the cut material through it, as it rubs across the surface of the saw. By using a jig to make my angle, I keep my cross cut square and I can insert a piece of wood here and as I moved through, I've got a square cut. I don't tend to drag my material. I can hold it firmly. I've got something to hold tight to and I can make a precision cut every time. The trick with these jigs is obviously that they need to be right up next to the saw. We'll add a stop block here. Little quick clamps are a wonderful tool. The jig works by measuring and gluing in a piece of wood to stop it at the particular angle I want, for my cut. This little thumbtack is actually in here because I was using, I had this jig already made at the 15 degree angle and I wanted a new stock block instead of the very long piece that had been in here, so I just wanted to pin it in place to get the cut for the length that I wanted. It looks like I settled on probably this one. I pull that pin out. I can obviously slide this back and forth. As you can see with this particular model, minor changes in the length of that cut made for kinda dramatic differences in the size of the final arch, so I had to play with that a bit 'till I got the exact size I wanted. Otherwise, assuming I'm measuring it, I measure out to my stop. I know exactly how long my piece is. I've got my angle and I can make my cut. If I'm, in most cases, where I have a long enough piece, I can comfortably hold the material, the long stock in my hand, as I move through the saw. In a couple of cases, I was cutting some very small pieces and so I made little, little finger clamps to hold the stock so that I could cut a piece of stock that was very short and still keep my fingers safely away from the blade as we moved through the cut. The main idea of the jig is to simply have something that allows you to hold your stock, full length, comfortably so that you can guide it safely through the blade and get that precision cut. These jigs are easy to make, quick to use. Much, much simpler and more precise than trying to constantly adjust your cross cut guide. Once you've made them, you keep them there. They're permanently set. You've got an angle that's not going to change between each setup. If you realize you didn't make quite enough, you don't have to go back and readjust this. You pull out the jig. Lots of things we make, we need to make many, many cuts of. Using jigs, like this, is one of the best ways to go. Another note, whenever you're using a table saw you need eye protection. You need ear protection too and that would be true even if you're using your little saw, down in the shop. They make, if anything, even more noise than a big table saw. I think that's about it. We've looked at a variety of cutting tools, knives, saws and files, all of which have different purposes for cutting different materials and different strategies, depending on whether you're making single cuts, multiple cuts, the thickness of material and the type.