Lubricating the cutting tool

[Geswearf]

Why do so many CNC mills come with a pump to flood the cutting area with lubricant (and a full enclosure to contain the splashes) and so few mills have this type of lubrication? Sure, I've seen the flexible lube arm with a nozzle on some mills, but these are not the rule.

Is this because a CNC machine works continuously and faster (probably close to the maximum speed for machining) for long periods, generating more heat?

 

[benmychree]

Likely true ---

 

[verbotenwhisky]

Why do so many CNC mills come with a pump to flood the cutting area with lubricant (and a full enclosure to contain the splashes) and so few mills have this type of lubrication? Sure, I've seen the flexible lube arm with a nozzle on some mills, but these are not the rule.

Is this because a CNC machine works continuously and faster (probably close to the maximum speed for machining) for long periods, generating more heat?

Its an option with the PM lathes, at lease it was with mine because I have the flood cooling system.

 

[matthewsx]

Yes, flood coolant allows max feeds and speeds, maximizes tool life, and lubricates the machine.

Machine shops are a challenging business, you need to run at full production as much as possible to be profitable.

At least that’s what it says in my textbook.

John

 

[Geswearf]

Machine shops are a challenging business, you need to run at full production as much as possible to be profitable.

That means very little manual machining...i.e. use power feed as much as possible, deep hogging cuts, and a fine finish cut?

 

[RJSakowski]

I bought the flood cooling option when I bought my Tormach PCNC 770. It produces better finishes due to the cooler cutting and chip evacuation. It works especially well machining plastics, totally preventing melting. However, I haven't used it in over a year. I don't do a lot of milling so the mill is idle most of the time. Maintaining correct coolant concentration is a chore and the coolant will go rancid after a while.

On a manual mill, you will have to have some sort of enclosure. That will obstruct your vision of the milling. On a CNC, you put your trust in the Gcode so observation of the milling process isn't as critical. Flood cooling requires upwards of 4 gallons of coolant. It also requires some means of monitoring concentration in order to keep it in the correct operating range. Also, running flood coolant requires a thorough washdown and cleanup after use which often exceeds the run time of small projects.

 

[RaisedByWolves]

Why do so many CNC mills come with a pump to flood the cutting area with lubricant (and a full enclosure to contain the splashes) and so few mills have this type of lubrication? Sure, I've seen the flexible lube arm with a nozzle on some mills, but these are not the rule.

Is this because a CNC machine works continuously and faster (probably close to the maximum speed for machining) for long periods, generating more heat?

This is to keep heat down and the chips clear.

 

[rwdenney]

Why do so many CNC mills come with a pump to flood the cutting area with lubricant (and a full enclosure to contain the splashes) and so few mills have this type of lubrication? Sure, I've seen the flexible lube arm with a nozzle on some mills, but these are not the rule.

Is this because a CNC machine works continuously and faster (probably close to the maximum speed for machining) for long periods, generating more heat?

Yes--that's why machinists call it "flood coolant" more than "cutting oil". The coolant is usually a water-based oil that has enough lubricity, but the main point of it is to take the heat away efficiently. Actual cutting oil may also be needed and if so will form a sludge in the coolant.

I don't use flood coolant because I don't machine fast enough for that to be really necessary. And also because my machines don't accommodate flood coolant. If I ever have production goals for a project, I may invest in a mist coolant, but for me brushing on cutting oil is usually good enough.

Rick "who makes blue chips occasionally but not orange chips" Denney

 

[RaisedByWolves]

I bought the flood cooling option when I bought my Tormach PCNC 770. It produces better finishes due to the cooler cutting and chip evacuation. It works especially well machining plastics, totally preventing melting. However, I haven't used it in over a year. I don't do a lot of milling so the mill is idle most of the time. Maintaining correct coolant concentration is a chore and the coolant will go rancid after a while.

On a manual mill, you will have to have some sort of enclosure. That will obstruct your vision of the milling. On a CNC, you put your trust in the Gcode so observation of the milling process isn't as critical. Flood cooling requires upwards of 4 gallons of coolant. It also requires some means of monitoring concentration in order to keep it in the correct operating range. Also, running flood coolant requires a thorough washdown and cleanup after use which often exceeds the run time of small projects.

Running the coolant every couple days will keep it from getting stanky as the bacteria that make it stink are anaerobic.
you could set your pump on a timer for this.

I also douse our coolant with some alcohol when it gets funky, then let it run a bit to mix this in and it kills the stink and bacteria.

 

[RJSakowski]

Running the coolant every couple days will keep it from getting stanky as the bacteria that make it stink are anaerobic.
you could set your pump on a timer for this.

I also douse our coolant with some alcohol when it gets funky, then let it run a bit to mix this in and it kills the stink and bacteria.

I don't really have a problem with odor. My problem is with way oil. It will combine with the coolant to form a gel like mass. My solution is to filter the mess though several layers of cloth which involves emptying the tank , cleaning, filtering, and refilling.