Turning the Barrel

Safety guidelines: Got long hair? Tie it back. Long sleeves? pull them up and secure them. Rings, other jewelry? Take them off, wedding bands too. Goggles over your eyes? Good, if not, get them. Got a long beard? Guess what, tie it back. Just as a side note, if you hurt yourself doing any of this don’t blame me all machines are different and you need to know your machine before continuing. If some of what you read won’t work on your machine, don’t do it.

Equipment needed

  • Lathe
  • Lathe tools
  • Centre Drill
  • Drill bits
  • Taps/Dies
  • Still Bristle Brush
  • Lubrication/Cooling Fluid
  • Files
  • Digital Vernier Callipers
  • Live centre

So, you should have 2 cylinders from the previous tutorial or already have the cylinders you bought. If you are using the cylinders previously done they should already have the centre holes for the live centre drilled out. If not go ahead and put the blank in the lathe so you can drill the small indents for the live centre to site. You should end up with something like this:

centre divot drilled

Now you have your centre dimple fit your live centre firmly into it and switch on the lathe at a low speed. What you are looking for is the live centre spinning with the blank. If it isn’t then it isn’t fitted firmly enough. What you don’t want is for it to rub, if it starts to rub then there is danger of it rubbing away the material of the blank which will lead to a looser fitting and the blank bending when you start to turn it. This is also why you don’t use a dead centre, friction is bad.

Once that is all set up you want to turn your lathe off and change the tooling you are using. You no longer want to use the roughing tool that was in place for when you made the cylinder. This time you want to use your left or right finishing tool. The left one will have the flat edge on the left and the right tool with have the flat edge on the right as below:

Left and right finishing tools.

I prefer to turn starting at the end of the blank and going towards the chuck so the most used tool of mine is the left turning tool as the motor and chuck is to my left. Yours may be different depending on your set up. Discover which ever is most comfortable for you and stick to it. There is no real wrong or right way of doing this part.

The first part is quite easy, all you are doing is stripping the blank down to just a smidge over the desired diameter of the barrel. for the most part this can be done quite quickly and roughly. When one side is turned down to the right diameter turn the blank around and to the other side. When the strands of the blank wrap around itself they can get quite hot, you will be tempted to take them off with your hand, Don’t! Your fingers should never go near the moving parts of the lathe. You used to be able to tell an experienced machinist by how many fingers they were missing, don’t be an idiot, use the brush to get rid of the strands, that is what it is there for.

One side turned down to the correct diameter.

Now you have something which is quite narrow and you can decide your first aesthetic decision. Take a look at your blanks and decide what you want to be used for the barrel, what you want to be used for a cap and what you want to be used for a section. Within that decision you need to choose which end of the barrel will have the threaded part for the cap and which part will have the finial (that being the opposite end to the cap end).

When I look at my blanks I know in general I want all the detail of the blank to be in the barrel and to contrast this I want the section to be relatively plain. The reason for this is simple. The barrel is what the user of the pen will see the most as it is visible when capped and when in use, so I pick the prettiest part for that. The section on the other hand is the part of the pen which is seen the least, it is either covered by the fingers or the cap and there is no need to ‘waste’ a pretty part of the blank on that. The cap is different, depending on whether you intend it to post it could be as important to the aesthetic of the instrument as the barrel is so you want it to look nice. If there are any pretty parts in the cross section of either end of your blanks you want that for the end of your cap if possible.

Now you have made the choice of how the overall pen will look put your thin blank for the barrel in your lathe and get your drill bit for the internal thread of the barrel (I use a 9mm drill bit for a 10×0.75 thread). You should already have a centre dimple drilled from turning it, if not quickly drill one.

As a bit of an aside here, thread cutters are measured first by the diameter then the pitch. I use metric threads but the numbering convention is the same for imperial.

You will want to set the blank back quite far in the chuck so that the chuck supports it when you are drilling. First thing is first, work out how deep you need to drill out, this is based upon the length of the converter or other filling system you are using. On your drill bit mark this depth or use another method to measure how deep your drill bit is going into the blank. You want to be pretty accurate as the last thing you want is a blowout, this is when you drill out the far end of the blank and create a hole going all the way through, when this happens it sucks, that is unless that it what you intend to do for aesthetics purposes, i.e. wanting to add in a metal or other material band or just having a different coloured finial.

Once you have drilled out you can now take the correct tap and thread the inside of the barrel for when you fit your section. When it is threaded take a file and while it is spinning just fine the inside millimeter or two of the hole, this will widen the hole just enough to fit the section.

You will need to be wearing a face mask every time you put a file or other hand tool anywhere near moving parts of the lathe, at some point the tool will glance off the spinning chuck and flick up towards you. If your lathe doesn’t have any guards there is a high likely hood that this will hit you in the face and it will hurt and will cause a lot of damage. The lathe is a serious bit of kit and given the chance it will kill you. Take every opportunity to improve safety.

Now with your hollowed out barrel with an internal thread you need to thread the outside of the barrel so that the cap can screw on. Place your live centre so that it sits in the hole you have just drilled out. You now want to turn the blank down for the first 5mm or so for your cap threading. This will be different for whatever thread diameter you are using (I do a 12.8mm diameter part for a 13mm thread cutting die). Once this is done then it has all the threads you will need.

threading complete

You can now think about shaping the barrel. To taper something on the metal lathe I turn steps, this is done much like the contour lines on a map. The closer together the turned parts are the steeper the incline will be. Once you have turned the steps you can smooth them out with the file being sure to take care and utilize the safety guidelines above.

stepped ready for smoothing.
smooth barrel ready for sanding.

Congratulations you have a barrel.