How do you guys drill holes small enough for wires to fit through when making top mount ditch lights? I plan on adding ditch lights to my SD60M but drilling is my first obstacle.
-Khang Lu, University of Minnesota Railroad Club
Well, first I remove the shell. I know, that seems obvious. But, it's important to check inside of both the shell and the guts of the engine to make sure there is clearance for the stem of the light inside.
Mark the spot where you are going to drill the hole. For this kind of work, where the position of the hole is pretty critical, I would start with a tiny pilot hole drilled with a manual tool like a pin vise. I've also got a mini-chuck, which is actually a small-bit adapter for a larger drill.
Once the pilot hole is drilled, you can work your way up with a series of larger-diameter drills, but the pilot hole should guide even the full-sized bit accurately. I prefer a manual drill for a single small hole like this, but I have a light duty variable speed cordless I can use too.
Of course, if you are blessed with a drill press, then use that.
It takes an iron man to play with a toy iron horse.
Get a set of small drill bits and a pin vise. There are sets that goes down to #80. Micro Marks sells the stuff. You could use say #44 magnet wire. I have but not in this type of lighting.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
SooLine720:
Are you asking about how to drill the core out of a ditch light casting or how to drill the holes through the locomotive shell?
I'm not sure what your level of knowledge is so I'm going to start with the basics. Please feel free to ignore any or all of this if it is below your level of understanding.
Sounds like you need to buy a pin vise and a selection of small drills. This is what a pin vise looks like:
https://www.walthers.com/exec/productinfo/285-92
For general use, if you buy a set of drills with one of each size from #60 to #80 that's fine (larger number = smaller size), but I would also suggest buying spares of certain sizes because you will most certainly break a few drill bits along the way. I would buy 10 each of #79, 76, 73, 70 and five each of #67, 64and 60. One or two of the larger sizes are nice to have, like a #55. The larger sizes are much less prone to breaking. You don't absolutely need spares of every drill size. For example, a #79 is very close in size to a #80 but much less less prone to breakage. For most hole sizes the difference between one size and the next is negligable. If you get into precision kit building the plans will usually tell you what sizes you need.
For coring a ditch light casting to install your own LED, assuming you are using an 0402 SMD LED (0402 = .040" x .020", SMD = Surface Mount Device, LED = I hope you know that one already!), you will need somewhere around a #64 bit for the final hole size. Start with smaller drills and work up or you will likely destroy the casting.
One type of bit to avoid are those with a large shank which tapers down to the actual bit size. Those are designed to be used with precision drill presses and they break very easily if being used by hand.
There are a couple of tricks to preventing the smaller bits from breaking. Most important is to let the drill bit do the work. If you try to force it, it will snap. Second, chuck the bit so that there is only enough of the tip showing to cut through the thickness of the material. This reduces the opportunity for the shaft to flex which is when breakage occurs. In order to get the bit to the spot where you want the hole you may have to remove the handrails. If that's not possible then try drilling from underneath.
Ditch lights should be wired with small diameter magnet wire as opposed to decoder wire with thicker insulation. The thicker wire will often get jammed between the frame and the shell. To prevent possible wire damage I grind out a small groove in the bottom of the deck and up the insides of the nose, so the wire can sit in the hollow and not be rubbed or pinched against the frame. I hold them in place with CA but that makes removal of the wire without damage almost impossible. Something like Elaine's Tacky Glue is easier to remove but it takes longer for the glue to set enough to hold the wires in place. Don't cut your leads short until you are absolutely certain how much length you need! Ask me how I know!
Prewired 0402 LEDs are available on eBay. I used to solder all my own LED leads but for the tiny stuff like the 0402s I buy them pre-wired. So much easier! The ones I buy do not have colour coded leads so I use a red paint pen to mark the positive lead.
Don't know if my blabbering on has answered your questions. Hopefully it has.
Regards
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!