Is a drip feed coolant advisable

Hi Guys,

Up to now I have been applying coolant (oil or paraffin via droping it on the stock. I was thinking of buying another press dispenser but camew across vapour coolant and drip feeds.

Quite simply can any one recommend a coolant system suitable for the Sherline and mill.

Chris

I looked into this for the Mill. The vapour ones i believe do create a, as said vapour. Which not only goes onto the work but also into the lungs. I discounted that idea. Personal choice obviously. But i guess if enclosed in guards maybe ok. The drip type i also looked at. Unfortunately this time of year has had me out of the workshop building a New Koi pond & Pergola so will probably get back to it during winter. Best of luck whichever way you go.

Steve.

Not come across vapour coolant. Do you mean ‘mist’?

I guess that the coolant feed method is really dependent upon what you make, the material being cut and the type of machine being used. I use traditional machines, a Myford 254S and a Seig mill. So I tend to simply pump feed coolant to the cutting surface. In my early days the use of drip feed and mist were frowned upon, as our apprentice trainer insisted that coolant is exactly that, coolant. He was adamant the simply brushing, squirting from a squeezy bottle or drip feeding would not do very much except make the work piece dirty. I continue in this way to this day and the result is higher cutting speeds, better finish and longer tool life. Other opinions are available.

I bought one of the cheap mist coolers off eBay and couldn’t get it to work consistently - i ended up modifying it by running a plastic tube from the nozzle down through the flexible neck through an aluminium block and out to a pump type spray bottle and the the alloy block has a couple of magnets in it to stick it to the lathe or mill.

It uses the original needle valve to control flow and the pressure in the pump sprayer supplies some pressure to get the fluid up to the nozzle which is set to drip every few seconds. Less mess and no atomisation and very economical as the drops are fed in right where the cutting tool is doing its job .
on the lathe i only use it for parting or on alloy if i want a better finish as i mostly use insert tooling for turning but on the mill i use it for just about everything as i mostly run HSS tooling .

Hi Chris

Here is a link you may find useful for coolant appilication

Drip Feed Coolant

One I have used for several projects is a 2 stroke motorcycle oil injection pump. You can use the throttle cable lever to adjust the flow or drive the pump with variable speed DC motor.

Eric

On the little Sherline and with the small items you are generally making a cheap artists brush and a pot will do.

Mist is not good for you, a "fog buster" type would be better if you actually needed it which I don't think you do.

one favourite method of applying soluble oil to small jobs in machine shops and toolrooms in the 1970s was the cylindrical plastic bottle which originally held Fairy Liquid washing up soap, there was always one on the end of Bridgeport tables for giving small jobs a squirt,then fairy changed the bottle shape and material. when I started it was any old tin or glass container with slurry brush dipped in it,either an old 1 inch paint brush or commercially made brush where the handle was a pair of twisted wires and the end wires wound around a bunch of bristles.

I'd largely agree with the above. Either use flood coolant or don't bother. My only exception is drilling aluminium alloy on the vertical mill where I'll use a squirt of WD40 down the hole to reduce the swarf sticking to the drill.

For small, low power, machine tools coolant simply isn't needed. When I get my instrument lathe going I won't be equipping it with any coolant, even though the baseplate does have a drain.

Andrew

Chris

I use a very similar method to XD351, tube in a bottle passes via an air control block through small hozelock coolant pipe, the tube is complete from end of pipe to the bottle and air passes around the tube and onto the tool.

I use it mainly to prevent al build-up on the tool, it is neither flood or mist but is effective in use especially with no coolant on chips get blown away from the work so you don't cut them more than once.

Full plans in my Album, Emgee

This is a bit of a side track, but vaguely related.

I use CT90 spray for cutting oil. No science, just what screwfix sell.

Recently, I bought a can off eBay, not having read the word 'foaming' - or at least not thinking about it.

It came, I squirted. It's like shaving foam! You can't see the cut! What's the purpose of this?

And despite my nationality (God's Country), I confess I'm strongly inclined to deep six it and by some transparent stuff.

Iain

Thanks for the posts Guys. As always you read what you say and have a think. The issue when turning on my Sherline lathe and mill is swarf building up that needs clearing.

I am minded here to take primarily Andrew and Jason's advice (as well as others here). Tired at moment so will reflect on this later...again thanks all for posting. You do have to be careful with a brush as from experience it can get caught up in the works. As I was using a bigger brush possibly the shorter artists brush may be the answer?

Chris

Coolant which you drip, dribble, spray, etc removes heat by getting hotter itself and running off, taking some of the heat with it. This is a slow process, unless you use gallons of it. Litres work too.The most effective liquid for this is icy water, as it can absorb more heat than any other liquid before it gets too hot. But water makes steel go rusty. I think what is needed here is lubricant. Not the same thing at all.

Cheers, Tim

“Coolant” and or cutting lube is useful for for cooling and lubrication, used in high volume and high pressure it is useful for swarf removal especially on automatic machines. The lubrication property can help with surface finish and also to help prevent a built up edge on some sticky materials like some grades of aluminium. Cooling can help to keep the cutting tool in its safe working temperature range. If your work does not need this sort of help then avoid the mess and work dry. Working carbide hard can produce a lot of heat In the tool edge and the job and flood coolant can keep things from overheating and improve the dimensional stability of the work, unlikely to be a problem in most home workshops. If you are working a tool hard without flood coolant then a dab from a brush may not be the best thing for a very hot tool and micro fractures can occur in the tool edge, probably not a problem either in the hobby shop.

Mike

Iain, the foam is useful for tapping as a quick squirt down the hole will cover the whole surface rather than most of it running down to the bottom.

Chris, I don't know where your workshop is located but any method that uses air is also likely to spread the swarf over quite a distance and if their is any lubricant mixed in then that too will get spread about. Even the odd dab of a cutting fluid will get flung off the work/chuck and soon leave a tell tale mark up the wall and across the ceiling so bear that in mind too.

Edited By JasonB on 22/07/2020 19:28:08

Your trainer was misinformed. Cutting fluids serve up to 3 different purposes; they cool and/or they lubricate and/or they remove swarf. Compressed air cools and removes swarf but doesn't lubricate. Tapping fluids only lubricate, whilst flooding with suds cools, lubricates and removes swarf.

For amateur purposes I often cut dry with carbide, but Aluminium cuts better when lightly lubricated with paraffin and is less likely to weld, and steel finish often benefits from a brush full of oil. I only flood cool when doing a lot of heavy cuts in steel because flooding is so messy.

The older I get the more I realise everything taught at school was over-simplified!

Intermittent heating and cooling of carbide cutters is not recommended as it can crack the carbide.

Paul.

Summary as I see it:

carbide cutters do not need a cutting fluid on Steel

HSS cutters may deform and may need a cutting fluid

Petroleum based oil is bad to breath in as a vapour

Water soluble oil is possibly OK.

The job of the cutting fluid is to reduce heat, reduce friction, prevent rust and otherwise not do damage to the equipment.

Question if / when using HSS what is a safe cutting fluid that comes in a squeezy bottle for ease of application?

i have found this;

https://www.advancedmicro-lubrication.co.uk/pages/safe-cut/product-range/index.html

or as an alternative can TapMagic be sourced in the UK

Finally for removing swarf anyone point me to a suitable mini air blower suitable for my Sherline operations?

Chris

Edited By Chris TickTock on 25/07/2020 14:14:34

I use an airbrush compressor to blow chips away from the tool on my small CNC mill. You need to have the mill in a box or chips will go everywhere. Won't work if you are using coolant. As CNC cuts can be rather long I added an ex- computer fan on to the end of the casing to keep the motor cool.

Thanks John, your so right a little box will be made to keep the chips from going astray. Possibly could use the air to blow the swarth away then give a drop of cutting fluid from a squeeze dispenser bottle.

Chris