Thread: Simple gravity fed coolant system

This is a simpler coolant system using 90mm PVC tube and fittings, a piece of scotchbrite, a couple of parts you can machine on your lathe and a couple of lawn mower inline fuel taps. I used this system for years, works great.
Pic 1 is PVC tube with cap glued in place and 8mm hole drilled about 30 mm from the bottom for the outlet. You need two of these.
Attachment 204713
This lot is: Blanking cap drilled for scotch brite strainer (can be glued in place if you like), blanking cap with 10mm tube for swarf tray drain tube, blanking tube with 2 mm breather hole, outlet banjo and aluminium plate drilled, tapped and bent to suit inside of PVC tube. Again two lots are needed.
Attachment 204714
This item is the distributor, it's just a 16mm bar with through hole, tapped at one end for clearing blockages, threaded at the other end for mounting to the swarf tray and a small tube on top for feed to the cutting tool and two press fit tubes on the side for connection to the two PVC coolant tubes.
Attachment 204715
I don't have any pics of the inline lawn mower fuel taps, but they can be bought from any mower shop for a few bucks.
Once you have it all together, place one PVC coolant tube above the lathe the other below. Attach 6mm tubes to the two banjos at the bottom of each coolant tube connecting the other ends of the tubes to the two fuel taps which are then connected to the two tubes on the side of the distibutor. The tube exiting the top of the distributor is then connected to a tube leading to the cutting tool. The distributor can be mounted on the edge of the swarf tray with a bracket to hold the taps in situ. Place a blanking cap, with a 2 mm breather hole, on the top tube filter cap, another blanking tube, with a 10mm hole, on the bottom tube filter cap and route a tube from the swarf tray drain through to the 10mm hole.
To operate turn the tap connected to the top tube on making sure the tap connected to the bottom tube is off, when the top tube is empty, just swap the tubes around and turn the top tube on making sure the bottom tap is off With only one 2mm breather hole in the top tube cap, the coolant never evaporates.