View Full Version : My Coolant System

22-02-2013, 11:28 PM
Thought I'd share a few pictures of how I've made my coolant setup.

The tank is a bit of wide drain pipe with an end cap on it. This lays nicely at an angle on one of the side braces of the machine.



There is then a piece of narrow gutter under the bed laying slightly 'down hill' towards the tank because there was a couple of braces one about 25mm lower than the other under the bed. I put open cell foam in this to filter the swarf.



I thought for a while about the best way to get the water which collects in that pipe back into the tank and eventually just cut a slot in the tank the shape of the gutter and drilled a number of holes for the water to go though.



I then put some holes in the bed above the gutter and popped some alu tube into it so the water went directly down to the gutter. I just need to cut some grooves in the HDPE to channel any on there into the alu extrusion. The machine is at a slight incline so fluid will (slowly) flow to the end with the gutter.


Now, a quick question, is it normal for the blue flexi things to leak like this? (Click the picture for video)

http://i608.photobucket.com/albums/tt169/tenson_uk/th_DSCF9308.jpg (http://s608.photobucket.com/albums/tt169/tenson_uk/?action=view&current=DSCF9308.mp4)

Robin Hewitt
23-02-2013, 12:55 AM
Now, a quick question, is it normal for the blue flexi things to leak like this?

May be the camera angle but that nozzle looks blocked, a blocked nozzle is guaranteed to drip :rugby:

In fact, if you have any kind of pressure in the pipe expect it to drip.

To reduce the pressure you can adjust the pump, bleed some of the pump output back into the tank, fit a bigger nozzle.

To avoid the nozzle getting blocked you need a filter, there are all sorts of pond filters available for koi-keepers, I use a filter bag to strain all the gunge out before it gets back in the tank, empty it twice a year, icky job.

Swarf will try to block your return system. I usually stick a blow gun in the hose entrance to clear it and have a selection of old paint brushes to rearrange it on the bed. You will soon find something that works for you.

23-02-2013, 01:21 AM
I blocked the nozzle to reduce the size and increase the pressure of the stream. I expected the flexi things would handle some pressure since coolant is meant to be quite powerful, isn't it? Enough to blast the swarf away I thought.

23-02-2013, 08:47 AM
those flexi hoses tend to split at the big end, that may be the problem.

Robin Hewitt
23-02-2013, 11:00 AM
coolant is meant to be quite powerful, isn't it? Enough to blast the swarf away I thought.

Coolant keeps things cool, if you add lubricant it can stop things sticking, maybe ease the tool through the metal somewhat. It washes the swarf away, but if you are end milling with only one nozzle you have to aim it high on the tool above the depth off cut. Coming down from above helps avoid any metal holding fixtures. Quantity is more important than velocity, without air in the mix it is a "flood" coolant.

Yes, you do see it used at higher pressure with multiple nozzles but usually the machine has a closeable door to keep it in. The door is plastered with coolant, nobody cares if the hoses leak a bit. Was the original nose better than the cheap Chinese version? I can't remember.

01-03-2013, 10:24 PM
Well I did my first cut today using the coolant. Big smile! :peaceful:

I still have a leak in the bed to track down but I think I know where to look. Other than that, it worked really well!

This test cut was on a piece of cheap aluminium that comes on the front of a tweeter unit for some speakers I make. I've tried to cut it before with an occasional squirt of WD40 but it always jammed up the cutter. 3mm cutters broke and 6mm cutters jammed and went blunt.

In this picture you can see both climb and conventional sides of the test cut. This was a 3mm cutter without any finish pass. Just to the left corner you can also see the poor finish I was getting before I had coolant. I imagine with good quality aluminium plate, 6mm cutter and a finish pass I'll get a really beautiful cut!

I'll post some pictures of the actual set-up later. Just to say though, with a skirt on the spindle I actually get very little splash from the coolant, just lots flowing over the bed.

Oh and I have a mix of 90% water 10% oil.


08-04-2013, 01:59 PM
A video of stuff in action -