There will be many occasions where you will need to cross drill brass tube during your detailing of a model you are building. This is not a difficult job to perform as long as you have a few appropriate tools and a very good quality sharp drill bit. Follow these easy to do steps for nice clean holes through micro brass tube.
In this demonstration I am using a short length of 0.5mm Griffon Models brass tube. First off you will need a pair of flat smooth jaw pliers, mine are only a cheapie pair I purchased many years ago but they have performed well. Pliers that have a spring to keep the jaws open do not work well in this situation as you will need to keep the jaws held closed for a period of time.
The second important tool is a pin vice and a good quality brill bit. I am using a 0.32mm Tungsten Carbide drill bit which is extremely sharp, but they can break very easily. A good quality HSS drill bit will perform just as well as long as it is sharp. The use of a pin vice makes drilling control a lot easier and the weight of the pin vice is usually sufficient to allow the drill bit to penetrate the tube.
Position the brass tube between the jaws of the pliers making sure that the tube is at least 0.5mm below the jaw of the pliers, this allows the drill bit a guide to lean on.
Holding the pliers firmly but not overly tight, place the drill bit in the position you want to drill the hole. Gently lean the drill bit against the jaw of the pliers and resting the tip of the drill bit on the brass tube, slowly start rotating the pin vice between your fingers, the weight of the pin vice should be sufficient to start the drill bit cutting into the tube. Keep rotating the pin vice until the drill bit has cut through the side of the tube, but only through one side. If you have a very sharp drill bit you will only need to twist the pin vice less than half a dozen times.
Once you have gone through one side of the tube lightly release the pressure on the
pliers and rotate the tube with the drill bit until the drill bit and pin vice are
now standing upright, 90º to the jaws of the pliers, re-
Once you have drill all the way through the brass tube remove the tube from the pliers, as you can see the drill has gone through the tube nice and straight with only a few burrs, these are easily removed with a fine sanding stick or pad.
If your drill bit is sharp you can see that a very neat clean hole is the result, this process can be applied to any size brass tube and any size drill bit, the larger the drill bit the lower the tube will have to be in the jaws of the pliers.
I use a piece of 5.0mm thick Perspex 1.5 inches x 2.5 inches. Make sure that the edges are true because this is where the holes will be drilled. This picture shows a lot of holes already drilled of various sizes and depths, these have all been used over many years. Perspex is reasonably easy to drill if you have good quality sharp drill bits. Drill the hole in stages checking as you go until you reach the required depth, this will determine the length of your cut brass tube. It is preferable if the drill bit you use is a fraction larger than the brass tube size, this will make removal of the tube easier.
In this example I am using 0.5mm brass tube inserted into a hole that has been drilled to 2.25mm, this is the size I use to make the main body of my turnbuckles. Make sure that the tube is pushed to the bottom of the hole to ensure that you will end up with the correct length of tube.
I use a new No.22 scalpel blade when cutting a new batch of tubes. Hold the blade against the edge of the Perspex and rest it on the brass tube, with slight downward pressure on the blade simple slice the tube with a forward motion of the scalpel blade, this will cut through the tube with one action.
The result will be a very clean cut with no deformation of the tube. The cut section of tube will remain inside the Perspex ready for removal. If the scalpel blades you are using are good quality you should be able to achieve many dozens of cuts from the one blade.
To remove the cut brass tube insert a 0.3mm drill bit into the brass tube making sure that the drill bit is pushed all the way into the hole. Slight sideways pressure may be needed to hold the tube as it is withdrawn, in most cases the tube will come out with the drill bit, push the tube the full length of the drill to make sure there are no burrs inside the tube.
Once you get the hang of this method you will be able to knock out dozens of small length brass tubes all exactly the same length in a very short time. I find it very important when making turnbuckles or spark plugs that the brass tube needs to be the same length to make the items uniform.