Re: [CAD_CAM_EDM_DRO] Coolant on a little desktop mill (ie a Sherline)

AbbyKatt wrote:

>Hello again my inexhaustable CNC army, :)
>
>Since I got the 10,000RPM pulley set for my Sherline (I highly recommend
>this to anyone doing CNC on a sherline, the performance of phenomenal!)
>I have been able to cut a heck of a lot faster (good), but for the first
>time I am running into problems with cooling (bad). The motor and
>spindle/pulley part is all fine, but the workpiece I was working on
>(aluminium) got pretty warm.. As the part is now pretty small it heats
>up way too hot for me to touch with even a few minutes of machining, I
>also have to continually spray WD40 on the cutting tool when making
>plunge cuts to prevent it getting ali welded to it and resulting in a
>lollipop of almiminum.
>
>So here's my question.
>Cooling Sherline/How?
>
>
>Since a sherline was never designed for cooling in mind, I imagine the
>leadscrews and other bits of ferrous metal are going to corrode
>horribly! Also, while my mill is somewhat nicely shielded with clear
>plastic panels, I am pretty worried about spraying coolant all over my
>workroom (my TV room/loung too, incidentally).
>
>

Well, I use a Bridgeport, and the problems are really the same, except that
EVERYTHING is ferrous. Good coolant has excellent rustproofing
properties. I tried Tri-Cool, which was OK, but really didn't help in the
tool life department. I then got a sample of En-Cool, from Engineered
Lubricants http://www.englube.com/ and found it to be MUCH better.
It also can sit in the sump for months without going rancid. (You dilute
9:1 with water.) The only sign of corrosion is where it gets under the
vise and sits for months. When I pull the vise off, there is a black
stain on the table. I'm not worried about it, it is only a little
darker than my
very old and dark machine anyway.

I have pretty well covered all the places that coolant could get into
the machine
(keeps out the chips, too). There is commercial stuff for Bridgeports made
out of fiber-reinforced rubber-like material. Bridgeports have "galleys"
at the ends of the table to collect the coolant for return to the
coolant tank.
You may need something like that, too.

I made up several different shields out of Plexiglas to catch the spray.

>What's a nice cheap solution for a machine of this size, or an elegant
>one?
>Will a windscreen wiper pump do?
>

Probably. I use a "Little Giant" all plastic pump usually used for swamp
coolers and A/C condensate drains.

>
>Can I use WD40 as coolant instead of that nasty yellow stuff? That way I
>get lubrication for free and my mill will never corrode (or does this
>mean that fine dust will get into the ways and grind my machine
>instead?)
>

But, is WD40 effective as a coolant and cutting tool lube? My guess is
no, and spraying a lot of it all over your shop will stink up the whole
house, and maybe cause a fire.

You can't cool more cheaply, more safely, and probably more effectively
than with water! You just need to moderate the corrosion problem, and
add some high pressure lubes for the cutting tools.

Jon