Shapeoko 3 Gravity Feed Coolant Dripper for Aluminum Cutting by hemocyanin

Last crawled date: 3 years ago

I've been cutting aluminum on my Shapeoko 3 and I wanted a method to drip coolant on the piece during the process. I was initially intrigued by the youtube video of a WD40 can being used as the basis for this system, but it required a lot of brazing and it also adds weight to the tool head. So instead I made my own and since I have a 3D printer, it was actually much easier.
This project will require
two 1/4" bolts (1" long) and two each nuts and washers.
1 brass 1/16" inner diameter tube (like this: https://www.amazon.com/5125-Round-Brass-Tube-Peggable/dp/B0009ILF6G -- the amazon price is crazy high, try a local hardware store) (unfortunately I tossed the packaging but when I measure the outside diameter with calipers, it measures 0.091").
One medical IV set (like this: https://www.amazon.com/Baxter-IV-Set-Extra-Port/dp/B003VP2MR0/ ) -- all I really wanted was the shutoff valve and some flexible tube and there are probably cheaper ways to make this happen, but I was lazy.
One 4oz bottle of 3in1 oil with the telescoping tip (the IV tube fits perfectly over this tip and makes a very snug seal) (like this: https://www.amazon.com/3-ONE-100703WD4-Multi-Purpose-Telescoping/dp/B01LRH9B04 -- the amazon price is insanely high, I paid about $3.50 for that at a local hardware store).
A sealant for the joint between the brass tube and the IV tube (I have a boat so I had 5200 laying around -- that will seal anything and doesn't mind oil or solvents once it is cured). I have no doubt that wrapping the joint with electrical tape would work too as I did something similar in my proof-of-concept.
To set this up you want something above your printer from which you can hang things. You screw the bottle holder to that. On the Shapeoko, the base mount is a tight fit (I used PETG because it is flexible yet strong) -- it doesn't need adhesive or anything. Depending on your nuts, they may be tight or may need some epoxy to hold in place. This adds very little weight to the tool head because the liquid is kept secured above the machine rather than on it.
To bend the brass tube, make a cone out of paper and tape it to one end. Tape the other end closed. Fill the paper cone with salt and shake and tap till the tube is filled with salt. You can then bend into the shape you need. Once it is bent, it is inserted into the printed end piece -- you'll likely have to drill this out if you print it flat, but it should be a stronger piece printed flat. I used a #41 drill bit to get a snug fit which would also allow me to move the tube up and down in the holder for different heights. It will also rotate in the holder. You can also adjust the bolt-together joints. This gives a lot of degrees of freedom making it easy to get the spout right where you need it.
Cut enough of the IV tube to suit your setup, keep the roller shutoff mechanism, attach one end to the extendable tip of the 3in1 bottle. For the end that goes on the brass tube, apply some sealant and then push down what seems an appropriate amount of tubing over that. I secured in place with some zip ties, but you could accomplish the same goal with electrical tape and no sealant.
Lastly, take a needle and poke a tiny hole in the bottom of the oil bottle. This will prevent vacuum from interfering with flow.
When you don't want the oiler in place, you can remove it at one of the joints and hang it up by your bottle. I made a little holder for a magnet I had laying around -- the steel bolt provides plenty for it to grab on. With the spout up at the bottle height, it won't drip.
I have included the source files, made with FreeCAD ( https://www.freecadweb.org/ ) so you easily make any changes you want to this. A sort of printed Z adjustment would be nice because sliding the tube up or down in the end piece is a bit fiddly.
The roller shutoff valve will allow you regulate the rate of flow coolant.
Once the 3in1 oil is gone, I'll try refilling it with real aluminum cutting fluid but as it is, it seems to work fine - nice finish, hasn't caught fire, haven't had any aluminum weld to the millend since I started doing this.