One drop of oil is plentiful, the model train gurus always say. That means one tiny drop of oil when you are lubricating your locos!
I had a simple lubricator that dates back from 1964. It was made by Shell lubricants for Scalextric model cars. The cork stopper was wearing out and it was messy holding it.
So I decided to build myself a new one. I bought a pack of sewing needles from Spotlight. They were 1mm dia. I also bought a dowel (wood) of diameter 12 mm from Art Friend. You can use a smaller diameter dowel but I find that 12 mm is comfortable for my hands. I measured 130 mm length off the dowel and cut it. (You can decide how long the lubricator handle needs to be.) Then used a tiny drill bit to make a hole for the needle to stick in. It is easier to stick the sharp end of the needle into the wood. I used a small hammer to bang the needle in about 10 mm deep. I then cut off part of the needle with wire cutters to have a length of about 30 mm sticking out from the dowel. Its up to you how long you want the needle to stick out. You control the drop size of the oil by the depth you stick the needle into the oil pot!
Do contact me if you need more info or help building one. All shops are based in Singapore.