Malcolm, I was reading the tech tips section and saw the part about modding your headlights to fit sidelights. I did this a while back and have a couple of suggestions to make things easier.
When I did mine I intended to use a hole saw rather than work up via a series of increasing drill sizes. Drills are a pain because they tend to grab and can mangle the sheetmetal of the headlamp bowl. Hole saws are nice but they are expensive, especially if you have to buy either a set or one with a special drill that goes with it. In the end I decided not to.
What I did was an old aircraft mechanic's trick. In the aircraft industry they drill sheetmetal with a "swallowtail" or "butterfly" drill which is basically the same as a wood drilling spade bit. However it is made to last a lot longer because its meant to be used for drilling metal. But- it's hard to get and expensive. The cheapie alternative is to just use a wood drilling swallowtail/butterfly/spade bit from your local hardware store and you will find you can drill a fair few holes before it gets blunt. You can now even get longer life ones which are basically the aircraft bit from days of yore. They are a pleasure to use and will do the job very quickly. I stuff some rags into the headlamp before I drill the holes to stop the drill going right in and hitting the glass. Otherwise you can set it up in a drill press with a stop on it.
When I did mine I intended to use a hole saw rather than work up via a series of increasing drill sizes. Drills are a pain because they tend to grab and can mangle the sheetmetal of the headlamp bowl. Hole saws are nice but they are expensive, especially if you have to buy either a set or one with a special drill that goes with it. In the end I decided not to.
What I did was an old aircraft mechanic's trick. In the aircraft industry they drill sheetmetal with a "swallowtail" or "butterfly" drill which is basically the same as a wood drilling spade bit. However it is made to last a lot longer because its meant to be used for drilling metal. But- it's hard to get and expensive. The cheapie alternative is to just use a wood drilling swallowtail/butterfly/spade bit from your local hardware store and you will find you can drill a fair few holes before it gets blunt. You can now even get longer life ones which are basically the aircraft bit from days of yore. They are a pleasure to use and will do the job very quickly. I stuff some rags into the headlamp before I drill the holes to stop the drill going right in and hitting the glass. Otherwise you can set it up in a drill press with a stop on it.