I'm interested in trying to make one of these:Mostly because of the price, but also for the challenge. The basic idea of this attachment is to allow coolant (water) to be pumped into a tool bit which is attached to the bottom of the shaft. A motor drives the top of the shaft. Water is introduced at the side of the body and presumably flows through perforations in the shaft and out an axial hole at the bottom.
The construction and machining seem pretty simple. But what kind of bearings or seals can be used between the body and the shaft that will handle, say, 20-50psi without without leaking? The shaft needs to rotate somewhere in the range of 3,000 to 15,000 RPM.
Does anybody have any clues about this? Am I better off to spend the 140 bucks and just buy the thing?