Coolant System

I will want to cut steel with the lathe, so I purchased this coolant system from Axminster Power Tool Centre for £67.94 including next working day delivery - not bad!

Specification:

1. Plastic, 9 Litre (2 imperial Gallons, or approximately 2.38 US Gallons) coolant tank, with metal painted lid.
2. 0.1 HP (approx 75 watts) coolant pump, max head = 60 inches, max flow = 35 Litres/minute
3. Plastic coolant hose
4. Magnetic base with tap.
5. Plastic filter for the coolant return.

Here are some pictures of the system, as it arrived, and in full flow, being tested before fitting. The magnetic base with tap, feed pipe and jubilee clips were included in the purchase

,, 

The nozzle produces a stream rather than a mist, and although the flow rate can be adjusted, you cannot change the form of the stream of fluid. This is probably no bad thing given the health problems which suds oil mists are being blamed for at the moment.

Fitting

The Axminter web site stated the size of the system as 360mm long, 240mm deep and 170mm high (I assumed the height was for the tank only, not the pump / motor), which would be just right, as the opening in the centre of the lathe stand was 365mm wide by 320mm deep, which meant the plastic tank should just slip onto the chipboard shelf I had made. Well - the tank may have been that size, but the retaining clips for the lid make it an extra 10mm wide, so it didn't quite fit! A hacksaw soon fixed that!

  !

The clips still hold the lid on firmly, so the modification was entirely successful :-)

The next challenge was the drain pipe from the tray sump, a  bent length of iron pipe. Unfortunately it was too long and fouled the tank lid, so it needed to be cut shorter. I didn't fancy trying to saw off the pipe in position, so decided to unscrew it, get it on the bench and modify it there. When I went to unscrew the pipe, it was difficult to unscrew, but "loose" in the thread in the sump. When I looked at where the pipe screwed into the sump from underneath, I could see it was bunged up with Hermitite Red and string !

here is the pipe removed from the sump.

No problem I thought - I'll just run a new 1/2" BSP thread on the other end of the pipe and shorten it at this end. I then discovered the reason for the Hermetite and string - the diameter of the pipe was too small! Obviously this was a "retrofit" item. I didn't have a 1/2" BSP tap, so I decided to use an old brass plumbing fitting to "chase" the thread in the sump and clear out all the Hermetite and other rubbish, hoping that the thread in the sump wasn't damaged and assuming if anything got ruined during the chasing it would be the brass plumbing fitting and not the thread in the iron sump. Luckily all went well and the sump thread was in good order. I then made up a new pipe from a 15mm compression plumbing coupling, a flexible tap hose and a short length of 15mm copper pipe :

This works a treat and allows me to have the pipe go through the return hole in the coolant tank top and also to move the pipe out of the way when I need to remove the tank. Also it shouldn't leak (I'm not sure but I suspect the original pipe would have leaked like a sieve due to the poor fitting. I just need to wire it up, but for the moment I'll just plug it into a socket.