Okay scratchbuilders, I need to pick our brains. How do I drill holes in thin brass? A normal drill bit seems to be like twisting a fork through spaghetti. I have tried sandwiching the brass between two pieces of wood, and still little luck. Any hints here?
How thin is the brass, what size and how many holes do you need to drill?
Matt
Thickness: About the same thickness as a Kadee #5 coupler spring.
Hole size: around 1/8" in diameter. I am planning on making some pickup wipers,, and need to drill holes for mounting them.
Perhaps something like this would work?
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A punch might work, although they often create a burr around the opening and can distort an even wider area around the resulting hole. Why such a large hole? A smaller screw, such as 00-90, 1-72, or even a 2-56 will have a head sufficiently large enough to hold pick-up wipers in place. The smaller drill bit, with cutting edges much closer together, will have less tendency to "grab" as it breaks through the thin sheet, too. Use a drawing compass point to punch a centering mark - perform this operation on a hard surface, such as a surface plate or even a sheet of glass - this will keep the bit from wandering. It doesn't need to go right through - just a "dimple". If you absolutely need the larger hole, drill it in stages, starting with a smaller bit, and working up to the size you need.
Wayne
You might even punch a hole right through with a map pin, and then use a 3-sided file like a reamer to open the hole to size required.
Andrew
You can get small hole punches in several places, Tandy Leather has several that are adjustable down to 1/16", and you might even look in a scrapbooking store. One is designed for leather, the other for paper, but there's no reason why they wouldn't work on thin brass. I've got a metal hand punch, but I don't think it goes any smaller than 1/8". I'll check, I can loan it to you if it will work for you.
holes in thin metal can be drilled if you sandwich it between thicker sheets of brass or steel.i would use 1/8 sheets held together hard with a clamp close to the drill site.
jim
I like Jim's suggestion. If you are going to need to drill a number of pieces of thin brass shim stock, it might be worthwhile to get a couple of pieces of steel or aluminum 1/4 inch thick that are bigger than the brass stock, and drill a few holes around the edges and just use bolts nuts and washers to hold the thing together.
The method that I use is to clamp down the brass in my drill press after I have marked all the holes with a center punch. Start with a pilot hole from a really small drill with the drill press set on high speed and work your way up with larger bits to the hole size that you want. Just use the slightest pressure on the bit and be patient. You may need to back up the brass sheet with a small scrap of would.
If you haven't cut the pieces to their final size, it's easier to drill the hole first if the pieces are still "stock" size, or at least quite a bit bigger than their finished size. Having a good chunk of metal around the hole will go a long ways towards keeping the piece from getting chewed up. You should also clamp them to keep them from trying to follow the bit.
Once drilled and deburred, you can cut them to their final size.
Thanks for everyone's advice. It sounds like i am going to play around a little to find what works best for my application. The hole does need to be about 1/8" as it needs to slip over a stud of approximately that diameter. I could alter my intended design, but i think I will try punching holes first.