Meet the Manufacturer - Calrec Audio (part 5)
Computerised Numerical Control
As we know, computers are great assistants in all functions of creativity and business and I suspect we have only just started to learn what they can do for us. Anyone who has done any studio metalwork themselves will know what time and trouble it takes to get things as right as they should be, and if you put the work out you find that much of the flexibility you need for doing small quantity work is lost. If a mixing console manufacturer is to be able to achieve sufficient flexibility without excessive expense, then producing a metal panel should be as easy as printing out a document from a computer. Can this be this possible?
We use a CNC (Computerised Numerical Control) profiling milling machine which can take the vectors from the AutoCad drawing and make all the necessary compensations for cutter width and set off and make the panels. It works to very close tolerances and one of the main benefits is the quality of the finished product. The biggest advantage is to us is that immediately the drawing is done on AutoCad we can transfer the disk straight down to the machine and have a panel off within a very short space of time, which for doing specialist work is a big advantage. It keeps it all under our own control.
If you look closely at a Calrec console you will notice that the lettering is actually engraved into the surface of the panel. Engraving was once considered (and perhaps still should be) a hallmark of quality.
The advantage of engraving is twofold. One, by engraving through paint or anodising into aluminium you can get a high contrast ratio, and because its very sharp it not only looks attractive but is actually easier to read than silk screen printing. You cant go down to very fine lettering with silk screen printing otherwise the process ceases to work properly. You can look at a desk such as the Q Series which has 30mm modules and is quite densely packed and its quite easy to read the engraving around the controls. The second advantage is that because the letters are cut into the aluminium, no matter how long the desk is in use or how frequently the controls are used the legends will never wear off, as they do on silk screened panels where you can actually rub the silk screening right off the panel. After many years of use our engraving is still as clean as it was the day the desk was installed. The lifespan of our consoles is probably a minimum of twelve years and an unknown maximum, because we have been supplying desks for many years now and most of the studio desks that we have supplied are still in service. A typical life in a television studio will be as long as the studio lasts, about twelve to fifteen years. Again we take the vectors off the AutoCad drawing to do the engraving. We have had to do a bit of software ourselves to convert engraving text into vectors that will drive the machine. It isnt as straightforward as you might think.
For the printed circuit board design we use OrCad. Because they are analogue audio printed circuit boards, it means that you cannot use autorouting because crosstalk is one of the main enemies, so although it has schematic capture the layout has to be done by a skilled person. But the advantage of the software is that having laid it out it will then do a check back against the circuit to make sure you have got the connectivity correct, which is a big help and gets rid of all the basic mistakes such as tracks wrongly connected and power the wrong way round on ICs. At least you know when you have done your verification that you are not going to have any collisions and the board will work according to the circuit when it comes back. Which means that its very seldom that you have to do more than one prototype of any board.