Cooling on mill

Do not use this system, it is a health hazard, the air that you breath in whilst working is saturated with tiny globules of coolant. Not good for your lungs.

This system was primarily designed for totally enclosed CNC machines.

All of my mills have built in coolant pumps. I use Castrol Hysol XF as a coolant and I keep the mix correct with a refractometer. How I use coolant depends on the mill.

CNC: I always use flood coolant (except for cast iron, brass and plastics) primarily to wash the swarf away rather than cooling the mainly carbide cutters.

Horizontal: As for CNC, except mostly for cooling as I only use carbon steel and HSS tooling.

Vertical: I almost never use coolant since there is no drip tray and the stuff gets flung everywhere. I wouldn't worry if a HSS cutter was running with the swarf coming off yellowish. For carbide tooling anything goes, the swarf is normally at least blue in colour and when running hard the cutter has a hint of red in subdued light.

A summary is that for carbide tooling I almost never use coolant (except for the CNC mill) and for HSS tooling I almost always use coolant (except where the material doesn't need it or on the vertical mill).

Complicated isn't it!

Andrew

When I don't cut dry, I use a coolant mist spray (like this) but without the coolant. Clears the chips so you aren't recutting them and helps cool the tool without getting messy.

You need an air source of course.

I use a squirt bottle with water based coolant. My primary goal is to prevent aluminum welding to the tool.

Air blast cooling! I haven't tried that yet. I'll need to rig up something to trap/collect the chips as they are thrown off.

Do not use this system, it is a health hazard

Only if you breathe it in! Only if the mist is made with lubricant as well as water! If really fussy, one can wear a face mask, but adequate ventilation applied, to drag the mist away from the area of the operator is quite satisfactory, I would expect.

Using water as a coolant is better than just compressed air - a far higher specific heat capacity for water - but every little bit of cooling can help in some situations.

I am with John Reese on this, a squirt bottle for lathe or mill. Most times however I just use a small acid brush and undiluted soluble oil. For home machining we are never in that much hurry to move metal surely ? My garage is attached to the house and my wife always complains if to much smell pervades weather from cutting oils or paint.

Fitting flood cooling to my mill must be my least cost effective workshop purchase yet. It's hellish messy and not usually needed for light hobby work, for which I use a squirt bottle &/or brush, or cut dry.

I do switch it on for 'heavy duty' work, for example when a lot of steel has to be removed in one quick session with an HSS cutter.

As always with choosing tools and technique, much depends on what you are doing. I usually find out what's best for me the hard way!

Dave

Edited By SillyOldDuffer on 23/12/2016 10:03:24

Sorry Brian, only just saw this - Christmas and all that.

I didn't mean to imply that I use the air system at full pressure. I have a spur taken off the main supply via a regulator which I use for this (and a few other things such as running small steam engines). I usually have the pressure on this section regulated to around 10 psi or so and I further control the air-flow with the valve on the (dry) coolant spray device. So it certainly doesn't throw chips all over the place .... just gets them out from under the cutter.