I have made a new frame for a set of 1″ chimes, so it made sense to extend the playing range up to the top G at this juncture. The frame has already been delivered, so now I have the time to make the bells.
The first thing I need is an example bell, in this case I asked for the F. Not only does this enable me to take all the measurements that I need in order to make any parts, but it also helps during the tuning process so that the new bells fit within the existing set.
It is now virtually impossible to get brass tube in the size that I want, let alone the correct material. Brass is an alloy, so there are lots recipes to get the required properties for the desired application. Over time, brass is being replaced (presumably by plastic) so the commercial requirement for these mixes has largely disappeared. Combined with the mills being bought out during global monopolization, this has resulted in higher prices and less choice. Of course, if I buy sufficient quantity (a metric tonne) I can get whatever I want, but I am instrument maker – I make musical instruments for a living therefore I am poor; spending thousands of pounds sterling on lengths of brass tube is just not going to happen. Additionally I would need four external diameters, and three wall thicknesses, that is twelve tons of brass tube! If I had that kind of money, I would retire to the Caribbean.
Fortunately I do have some stock, which still equates to well over a thousand pounds just sitting on a shelf! In amongst those tubes I did indeed have a length of the correct material, which is the major hurdle negotiated. So the first job is to chop it into lengths longer than the bells I need to make. There is nothing worse than making a bell only to find that it is too sharp right at the end of the process when the tuning happens. With the two new tubes cut, I drill the holes for the string to match the existing bell and stamp the tubes.
Using the existing bell as a reference, I measure the cap dimensions so that I can form the inside of the cap from solid bar. This form is then cut off the bar giving me two crude caps. I use a donor bit of tube offcut as a temporary bell and spot solder the caps in place. This enables me to hold the offcut tube in the lathe to form the external shape. My lathe doesn’t have a large enough bore to pass the tube through its headstock.
With the caps now made, it is just a matter of removing them from the donor tubes and soldering them in place on the actual tubes. After they have cooled, I hand polish the whole bell, then tune it and send it off to be chrome plated if required.