A challenge when machining metal is to keep the cutter cool and lubricated while also removing chips. If manually machining, it isnít too tedious to keep a cutting fluid soaked brush handy. But if you are CNC machining, it is a real pain to be tied down to the machine. Straight compressed air will remove chips and does help cool the cutter a little. Adding a coolant that also lubricates makes a huge difference.
Many commercial system use flood coolant which requires a means of containing the liquid and recycling it back into the holding tank. Other systems use mist cooling which can quickly fill the shop with fog and canít be good for your lungs. A third cooling system exist: Minimum Quantity Liquid (MQL). Very little liquid is used so there is no need for recycling the used liquid. There is also no misting so no fog. The main problem with MQL is the cost of commercial systems.
Brian Lamb design a homemade MQL system. I built a modified version and it cost me around $175 including a lifetime supply of coolant. This cost does not include an air compressor.
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