Making coolant system automated

[phantomcow2]

I have a small milling machine soon to be cnc converted (when a 4 jaw chuck arrives to do a little boring work). Well i think one of the advantages of cnc is the ability for jobs to run for several hours without me having to turn handles all day. I dont think i will appreciate having to stop whatever i am doing and spray coolant on the piece every 10 minutes either...
So i ask, what are the primary components of an automated coolant system?
Obviously there will need to be a pump
I was thinking about using a locline to direct the coolant so it follows the Z.
Some sort of reservoir, perhaps a 5 gallon bucket?
Hose to connect it all
But what i dont understand is how do you make it controlled by the computer? I know you have to use a relay, can somebody further explain this?

[Al_The_Man]

The common M codes for coolant on/off is M8 M9. The machine control logic is written to turn the appropriate output/relay on and off. The logic for this is almost nill as usually there is no conditions required for this operation.
If your control has pre-written routines for M8 M9 then it is usually a case of hooking up the pump to the output/relay assigned for this.
Al.

[phantomcow2]

What it is that I am confused on is the hardware setup with it. How to make it actually controlled by the computer, what electronic bits and cables I need.

[Al_The_Man]

This depends on a great deal on what control you are using, I assume you may be wanting to go the serial port way with a PC, if so your controls s/w would either require the M8 M9 code built in with a pre-assigned output for that M function or you would have to write it if the software allowed.
Once you have a pre-assigned output which will probabally be at 5v logic level, you then would require something like a 2n7000 transistor to switch either a mechanical or solid-state relay.
There are I believe a few prior posts with diag. on this issue if you search the forum.
Al.

[phantomcow2]

I tried searching the forum but i am not sure what to enter for a search. I did "coolant", but that is far to vague. What is it I hear about a relay that i needed?
Thanks for your help

[CNCgr]

It would help if you told us what kind of control you intent to use. I use TurboCNC and it lets you specify a pin on the parallel port that will go high or low according to M7,8,9 commands. All you have to do is connect this circuit to said pin and you're good to go.

I don't have coolant yet but this circuits works fine for my spindle relay.

[Al_The_Man]

Here is another previously from the forum http://cnczone.com/forums/showthread...92&page=6&pp=5
Al.

[phantomcow2]

Ah, I am using TurboCNC (or plan to, when i get the conversion done entirely).
I have a hobbyCNC 4 axis board if it matters

[CNCgr]

Originally Posted by phantomcow2 Ah, I am using TurboCNC (or plan to, when i get the conversion done entirely). I have a hobbyCNC 4 axis board if it matters

Only thing that matters is if it uses all in/out pins on your LPT port. If you have one unused output pin, plug the above circuit to it and configure in Turbocnc that this pin is the coolant output.
Connect the pump to the relay, do some plumbing and you're good to go.

[dscolwill]

Hi
I use turboCNC to run a denford triac which like many small mills doesn't have a very good drip tray for collecting coolant. I have just finished building a spray mist unit which should use much less. If you don't want the hassle of making one there is a guy in the States selling them on Ebay ($20 or so). On the subject of the relay there is a circuit for driving a relay from the parallel port on the turboCNC site (I think ) or it maybe on the mach2 site.

[CNCgr]

Originally Posted by dscolwill there is a circuit for driving a relay from the parallel port on the turboCNC site (I think )

Yup, I posted it above!

Nikolas

[Al_The_Man]

You may also want to check the link I posted above, the advantage of the 2n7000 is that it does not draw any current from the port as the 2N2222 does.
Al.