Quote Originally Posted by NeoMorph View Post
I’ve got a feeling that he may play Kerbal Space Program. LOL

Back to my “upgrade” I’m abandoning the attemp as upgrading it would need me to replace too much. A friend has said he will help me with the heavy stuff if he can have a go at making stuff with it (which I think is a fair trade).

So it’s actually time to start planning a machine from scratch. Spent today looking through water pump requirements as the advice is all over the shop... “use a pond pump it’s the cheapest”... “Don’t use a pond pump ffs”... use a 12v water cooling pump and use a pc dual radiator”... “don’t use small pumps as they don’t pump enough to get it all through the narrow pipe”...”don’t use PVC pipe, use expensive anti microbial silicon pipe”... and on, and on, and on. Made my head spin.

So once I get my spindle I think I’ll set up a system to test actual flow rate and temp. ... and oh sh1t... we just left the EU. *cry*
I went round this loop a few months back, there's a thread on here about it http://www.mycncuk.com/threads/12791...cooled-spindle

The key things I learned are:

Distilled water doesn't go green even after several months in a shed which regularly reaches temperatures approaching 50C.

The diameter of the long runs of PVC pipe makes a huge difference to the flow rate and is more impotant than the size of the pump itself. I used thicker (8mm I think) pipes with short stubs of thinner stuff to connect into the spindle and got double the flow rate.

The head of water also has a big effect on flow rate for these small pumps so you cannot put the water tub on the floor under the machine.

I have no radiator, just a plastic tub full of about 15 litres of distilled water. I don't do and partcularly heavy cutting and there is no signifficant rise in water temperature.

I don't waste time with a pump stop/start control. I use a mains powered submersible aquarium pump which is fed from the same switched mains supply as the VFD. If the VFD is on the pump is runnng which might just improve cooling between jobs.

And one last one to watch out for: If the return pipe falls out of the tub onto the floor all the water can be siphoned out of the tub through the pump even if it's not running!

KISS!

Kit