Mist Cooling for Desktop CNC Boxford 160TCL lathe

[JohnnyK]

Has anyone tried mist cooling for small cnc lathe?

[depronman]

Not mist but a very controlled drip of coolant using a step motor powered peri pump
I can turn constant for about 8 hours on around a litre of coolant mix. I do not recover the coolant as most evaporates and the remaining oil sticks mainly to the swarf
It works incredibly well

I would not want the most from the coolant mist floating around in my small shop nor the constant noise from the air blast and compressor running a lot of the time

Paul


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[mekanik]

If you were thinking of using Ethenol, please read this Medical Report.
https://www.tandfonline.com/doi/full/10.1080/24734306.2020.1768341
Regards
Mike

[JohnnyK]

Glad I asked this question/ Thanks for your replies and the health safety warning as my workshop is small. I did have exposure to mist some years ago using my open VMC as you can't see it it so fine.
Paul I like the idea of a stepper motor powered peristaltic pump with a controlled drip rate. I will do some research to make up a small system. Do you use normal coolant mix or ethanol water?

[johnsattuk]

My effort

[depronman]

Glad I asked this question/ Thanks for your replies and the health safety warning as my workshop is small. I did have exposure to mist some years ago using my open VMC as you can't see it it so fine.
Paul I like the idea of a stepper motor powered peristaltic pump with a controlled drip rate. I will do some research to make up a small system. Do you use normal coolant mix or ethanol water?

Normal soluble oil and water at around 6% oil
When thread cutting I find some engine oil from the oil can works better than the coolant drip and as I don’t recover the coolant no issues with tramp oil
I made mine from mainly 3D printed parts three skate board roller bearings and a length of model aircraft silicon tubing plus a nema23 stepper I had lying around. Control was an eBay special rotary knob that generates step pulses and a £6 stepper driver. All working from 12v from the pc psu

Paul


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[Muzzer]

Paul - I'm struggling to consider 1 litre of fluid over an 8 hour period to be a "coolant", rather than a lubricant. That's around 2ml per minute if my sums are right. Even if it were fully evaporated during machining, that's got to be a fairly small cooling effect. When you say it works incredibly well, are you referring to the surface finish rather than the temperature of the cutter and work?

[depronman]

Both, the part comes off cool as does the tool. Surface finish is excellent
Tool life is also excellent
I turn mainly aluminium

I dried it dry first and got pick up on the tools and poor surface finish. Then tried a brush and coolant and was much better but I didn’t like the idea of being there with the brush and coolant all the time so devised the drip method with the peri pump
Pump on off is controlled under gcode from linuxcnc but speed of pump rotation is on a manual control knob. 90% of the time it is in one position but I do turn it up for parting operations

Paul


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[John11668]

These dont break the bank https://www.ebay.co.uk/itm/402440742823

With a controller https://www.ebay.co.uk/itm/193283325154

I could almost afford them. Has anyone else tried similar

Maybe if I get my spindle working again I will try them with some coolant

[JohnnyK]

These dont break the bank https://www.ebay.co.uk/itm/402440742823

With a controller https://www.ebay.co.uk/itm/193283325154

I could almost afford them. Has anyone else tried similar

Maybe if I get my spindle working again I will try them with some coolant

Should work well especially if you mounted a flexible nozzle to drip on working surface. You don't really need a stepper motor for this application. I would go for a fused 3 Amp controller board version though to give you a margin of safety due to voltage spikes from motor.

[dazp1976]

I've seen many lathe videos using a flood coolant stream from aquarium pumps, but not mist.

[Muzzer]

I used a central heating pump on my Bridgeport. They do a fine flow rate and also a big static head. The main downside is that they don't self prime but if you mount the pump below the reservoir surface, this isn't a problem. Pretty quiet and don't even mind being stalled long term if you turn the tap right off.