Cheap Coolant system for a mini-mill

I am now making an El Cheapo coolant system for my mini-mill
I have made a drip tray of 40mm high with a boat basin drain that will go to a bucket with a piece of pipe. The bucket will be of a size that will be fixed to the side of my mill stand.

Inside will be a fountain water feature pump that will lead the water to a mill cooland spout, equiped with a small tap. I will direct the water to the spot where the cutter meets the work piece. The pump at its slowest setting is a little strong, but closing the tap a bit control the water flow.

The mill is mounted on spacers, on top of the drip tray, equiped with silicone washers. I will also waterproof it further with a proper sealant tomorrow and test the dqay after tomorrow.

The pump can deliver up to a 1000l / hour. I am aware that there will remain a little water in the drip tray that will evaporates during the day because of very hot conditions, as well as due to spatter, but the loss will be minimal. At least now my cutters will remain cool.

Any other ideas? Any points I have to take in account?

Johan

Hi Johan,

You seem to get on well with plumbing!

I assume you plan to use suds (soluble oil & water) not neat cutting oil?

Neil

Amix of 1 : 20 soluble oil and water. Greenish in colour.

Hi Johan,

If your pump is not specifically rated for oil you may find it runs for a while then seizes, as the rubber shaft seal swells from oil exposure.

However, the inexpensive "parts washer" pumps sold at discount tool places are rated for oils and solvents and in my experience will work for water also.

If you have problems with your fountain pump you might try a parts washer one.

Any pump you use will need a very fine screen to keep out chips and metal powder or these will become embedded in the seal (and impeller, if it is rubber) and cause trouble.

Personally I like a cheap paintbrush and a tin can to hand-apply cutting oil. Soluable oil makes a heck of a mess of the machine slides and can go septic and smelly if stored too long especially in warm weather.

JD

Hello Johan,

I made my coolant sytem from a 12 volt car windscreen washer pump and a 4 litre plastic bottle. Power from a 12v battery and variable resistor for speed control. Plug pack charger to keep battery topped up.

Suction for the pump is from the side of the bottle, not the bottom so any swarf is not picked up.

Paul.

Johan,

I have used exactly the same system as you describe on a Kennedy power hacksaw for a number of years without any problems whatsoever. My only 2 comments would be that firstly you need to aware that the maximum head is quite limited if you are to maintain a good flow. In my case I have limited it to 300 m/m , and secondly, in order to avoid potential problems with Legionelle contamination which may occure in water-based systems ( which yours and mine obviously are) then it is important to maintain the system properly and clean, flush and replenish the system on a regular basis. It is difficult to give precise guidance since frequency depends on usage, amount of use, ambient temeperature and concentration. In my case, I have undertaken this work on a regular 6 monthly basis.

Hi Johan.

If you use a rectangular shaped bucket you could glue in a couple of baffles to slow the coolant flow down and this will allow the sediment to settle out , you could use some sheetmetal and glue them in with sealant just to hold them there .

I find the silicone type sealer that works on wet surfaces will stick to just about anything includine me !

What about using some flyscreen mesh as a filter ? Maybe you could use some of this to form a swarf bag that could be cable tied (zip tied ) over the end of the return pipe ?

You could remove it to empty it easily and re -use it .

Ian.

Re coolant filter...I use the following on centerless grinders..(very very fine swarf)...

one leg of tights or a stocking as your final filter back to coolant tank...use flour sieve as course filter on way to stocking..some where easy to empty....skip this if nothing caught on first try...

... or in the light of other threads maybe a sock....

The windscreen washer pumps work well and you can control the speed with a variable voltage power supply. Just note that there seem to be two types, one uses tufnol gears in the pump and one uses plastic. I would try to get the former I've been using (and abusing) one for eight years with no problems..

Russell.

I also used a windscreen wiper motor for a coolant pump on my lathe, see

**LINK**

When I was looking at making this mod I found some windscreen washer pumps (branded Linwood) that had rubber impellors. This washer pump was unsuitable for oily fluids.

Mike

All these motors and pumps make my gravity coolent systems look a bit pants, boy I have a long way to go.

Al.

My system uses a 250 ml squeeze bottle (PVA GLUE), I didat one stage have a coolant system on my 6 x4 hor/vert band saw, it consisted of a car windscreen washer pump, but it could not handle the soluble cutting oil. When it was working, about 9V was all that was needed. Ian S C

OK, here is my humble attept:

First, I have used a 17l bucket, cheaply bought from Plastics for Africa. The nearest I could get in the shape that would still allow the garage door to close.

I have added a drip tray that I have painted gray. On top of the mill you can also see the motor cooling system I have added. Now the motor runs cooler as well as the milling cutter.

The mill is mounted on spacers, that I have sealed with silicone rubber seals as well as a lot of silicone. It is not leaking at all.

The drain is from a boat shop. A smaller than usual basin drain, linked with a pipe to the container.

The return pipe I have covered with a T-shirts sleave to catch all steelal swarf. The material is freeflow for the water. The motor is lying loose. I will make a T fitting later to circulate some fluid directly back to lighter the strain on the motor. It is stronger than needed.

The pipe is coupled to a cheap plastic coolant spout set. Easily and very cheap to replace. This whole set-up is the price of one milling cutter.

Here the coolant is running at the rate I like currently. Time will learn if I should adjust. The flow is aimed on the workpiece, well away from the cutter, but the cutter get enough fluid to stay almost cold, but without the rotating cutter spattering water. (OK, OK, OK, I know the cutter is stationary but I have already switched off when I realised I forgot to take a pic of this last step.

This is a cheap set-up. Only time will learn if the motor's seals or the motor will last. Some people say it will not. Other said they have used it some years like that. So the hell with that. I am trying. If it can last at least a year, then I would have got my money back. I will have to drill a drainage hole in the tables side plate, as currently the coolant is damming up in the t-slots. The cover plate can be removed, so a hole of about 6mm will be enough.

Edited By Johan Crous on 23/01/2013 17:06:31

I have milled for about an hour today. The motor keeps moderately cool and the cutter remains cold. IT works, even for a homemade carbide insert dovetail cuter. However I have ruined the cutter that ran too hot before the coolant. Tapping fluid as a coolant did not cooled it down enough. The cutter, after sharpened will again be excellent for aluminium and brass.

There is one further need, and that is perspex sides as splash covers. The dovetail cutter makes a mess!

Hello,

Plastic garden spray bottle. Remove atomising spray lance and replace with proprietary magnetic base and positionable spout. Fill with your favourite soluble/non soluble lubricant. Drip tray to catch back into a bucket. Pump handle mandraulically. Coolant sprays out, empty bucket back into spray bottle when done. No electricity required.

Carl.

Johan,

All I would add is a bit of gauze/wire wool etc actually in the drain plug hole to catch swarf before it gets into the pipework,

A bit of that stainless steel pan scrubber from the supermarket kitchen aisle would be ideal, and top off an excellent job.

Have finished putting together my mist / coolant system for my WM16, have connected it from my compressor a tee piece through a surplus garden sprayer container ( suitably modified ) to a home made mixer block with aquarium variable flow valve for the liquid & adjustable air valve & it works, to a degree, I can get air jet on its own & same with coolant on its own, plus can get a mix of both. The trouble I have is with the flexible coolant spout set, it leaks at just about every other ball joint with any of the combination of the aforesaid. I have tried to rotate each ball joint to check for seating in the mating cup ( they are all stiff ) as I reckoned it might need some bedding together... just the same result ... air / water or both still leak from the joints. Looking at Johan Crous's write up & pics (earlier on in this thread ) his spout system doesn't show a drop of anything coming from any of the joints... I have considered reverting to a straight plastic pipe for the nozzle assembly... Have I missed something in the set up? ... any help would be appreciated...

Not operating at the mo'... but out of the 21 ball joints at least 12 of them leak.

George.