I've been using Scott Oilers (and others) for years, but have never been completely satisfied with them. The quantities of oil dispensed was never consistent. It seemed that there was always too much or too little being dispensed. Additionally, the oils used, at least in the Scott Oilers, were pretty thin and therefore there was lots of fling-off. The rear wheels were always a mess.
To address some of these issues, I decided to make my own oiler:
90 weight hypoid gear is gravity fed to the chain through the solenoid.
A microcontroller monitors the ambient temperature and adjusts the time the solenoid is on to provide a single drop at the varying temperatures. A 4 position dip switch allows selection of the time period between drops. As configured now, there are selections of 1 through 10 minutes in one minute steps, and 15 through 30 minutes in 5 minute steps.
The oil reservoir is simply a 1/2" tube that runs to the solenoid:
It snakes up to where you see the capped end. After filling, the end of the tube is tucked under the plastic panel at the rear.
I'm still experimenting with time period intervals, but so far, 15 minute periods have worked well. The chain remains moist and there is virtually no fling-off.
As an aside, I've never used gear oil on my chains before. I'm really pleased with the performance of the gear oil. It seems to provide a cushioning effect with the chain going over the sprockets. It's both quieter and smoother than what I have been used to.