Really useful tools

Over the past while I’ve come across, or rediscovered, various tools that I’ve found quite useful in making models. Here are three I find pretty cool. I’ll probably add to this list as time goes on.

Offset knife blades

Standard X-Acto style blades are commonly equipped with the classic #11 blades. These are the pointy triangular types. I find them less than great, mainly because they have such a tiny slender tip. This makes them really fragile, so they’re always breaking. That’s great for the manufacturer, but less so for my wallet.

A blade I find more generally useful is the #16 offset “scoring” blade. This type has a small bit at its tip, which means it’s less pointy. But it’s good for cutting as you can hold the cutting edge pretty flat without going at an awkward angle. The angle of the tip is less acute, which is also why it’s less fragile. The fact that the offset cutting edge is short may seem crazy, but in reality how often do you use the entire length of a #11 cutting blade?

Another useful one is the #2 which is similar to the 11, but which has a thicker base and a slightly squared off tip. This type is sturdier than the 11 and takes a bit more abuse than its more fragile cousin. Up to a point, of course.

Digital calipers

Measuring fine details can be tricky. Even if you can stick a ruler somewhere the marks can be quite wide or hard to read. You also have to make sure you’re not looking at the thing at an angle, since that can throw off your measurements thanks to parallax.

The answer is a pair of digital calipers. These are devices with a ton of tiny parallel wires embedded in a ruler. A little sensor detects these wires using capacitance as you slide the measuring section along, giving you extremely good accuracy - down to a tenth of a millimetre, typically. The results are shown on an LCD screen. The information is retained when the device switches off, so you can go back and look at the figure.

High quality machinists’ tools can be mind-manglingly expensive, but there’s also a ton of super-cheap ones on the market. However I don’t know how reliable the cheapies are. I do know that I bought a pair at bargain basement prices that only lasted a couple of years of pretty light use. Then the calibration went out of whack, rendering the whole thing useless. Are they all that lame? No idea.

I looked for a hopefully sturdier set. However I noticed a lot of different brands and models all seemed to share the same plastic housing and LCD/button arrangement, suggesting they’re all electronically identical inside. So I went for a very different looking one with a larger screen, on the theory that a different make or model must be involved. It also had steel jaws and handles, which are harder to chip than the plastic ones. So far so good.

Fine razor saw

Most razor saws aren’t actually razor-thin at all! Most are surprisingly thick. The usual X-Acto, Expo, and Zona blades are fine for cutting larger objects, but they suck for tiny things. The problem with thick blades is that you lose a ton of material where the blade cuts through. In other words, most blades have a very thick kerf.

However, a little known Czech company called JLC makes very nearly razor-thin saws. These are impressive for cutting details out of objects without sacrificing too much material. Of course, the blades are fairly small - about the size of an actual replaceable razor blade - and so aren’t any good for cutting larger pieces. But I find them perfect for trimming tiny models 3D-printed using brittle acrylic plastic resin.

The blades are almost paper thin, and have two cutting edges. One has 20 teeth per centimetre and the other an incredible 34! (that’s 51 and 86 teeth per inch for non-metric people in Myanmar and Liberia) Compare that to around 30 tpi for typical “razor” saws.

JLC sell optional wooden handles, though for very slow and precise details you could hold the blade by hand. The handle is recommended though, since it gives you more control and minimizes blade breakage owing to flexing. They also sell spacers that can fit between blades. I’ve never needed these, but the idea is that you can cut precisely parallel cuts by stacking more than one blade together into a sandwich.

Of course the blades have a low height and this limits the depth of the cut possible, to around 6mm if you use the handle. And the thinness and brittleness of the blade does mean you can’t hack away with wild abandon - the tool is fairly fragile.

Incidentally the saw is available in an “anniversary” set that includes a sturdy plastic case, the handle, and a bunch of spacers.