So I had this idea tonight to build a fluid dispenser controlled by an Arduino. The problem I want to solve is dispensing lubricant fluids in metered amounts for my RV. Houdini would like my RV, it’s very difficult to access the filler locations. It’s nearly impossible to add oil without spilling it. A funnel isn’t the easy solution because of the access. My RV is far from being alone with this problem. Almost every Bus has the same headache.
So why not use a pump? Great, but how do you control it? Hmm… well an Arduino with a push button or dial interface and an LCD and maybe a couple of LED’s. Add a printed case and a peristaltic pump and a way to count revolutions and you should be good to go.
Here’s a perfect solution…. a stepper driven peristaltic pump… http://www.aliexpress.com/item/Kamoer-peristaltic-pump-12V-DC/1850266365.html?spm=2114.40010308.4.38.N8z9VZ
Way too expensive though…. $90 plus $30 in shipping for a $20 motor and some tubing… the rest could be 3D printed dirt cheap or fabricated from metal. Would need to include a stepper driver, but that’s fine it solves the metering issue. 320ml/min is about 8oz/min so a gallon would take 8 min to dispense…. that’s fast enough for function.
Here is a $35 version that is about half as fast… http://www.ebay.com/itm/Peristaltic-Pump-Dosing-Pump-With-42-Stepper-Motor-Tubing-Hose-Pump-CN-/361476915848?hash=item5429b40288:g:b2YAAOSwxCxT6ft4 for 1/4 the price.
I think this is doable. I’ll look into it when I have time later this year.
A small LCD like this: $9
A rotary encoder: 76 cents
and a start / stop button: $1.50 or less
I think it’s pretty do-able. I’ll definitely get back to this because putting oil in the engine is a nuisance and it has to be done every 1,000 miles or so. It’s just part of running an old Detroit Diesel motor. They leak, eat oil, and smoke a bit when started, but run forever and are easy to maintain.