Do I Need A Coolant System?

[grepper]

Sage advice I'm sure. In fact, that's exactly what I plan on doing. However, at least from my current neophyte perspective, I doubt the coolant thing will ever be exactly a no brainer. Other than attaching a 1 x 10-8 mbar vacuum pump to the large hole I'm drilling in the side of my wallet, coolant seems to be the one messy, disgusting, downside to CNC.

 

[Cheeseking]

Grepper fwiw I run dry almost exclusively and rarely have a problem. I'd rather avoid the mess and deal with wearing out cutters faster. Carbide is almost mandatory if you want to cut steel dry. HSS will smoke in no time.
Like Jim pointed out keep the chips clear especially in slots or pockets. A little compressed air stream helps greatly to evacuate chips and provide some cooling. In a production setting flood coolant makes sense but for a home shop the tradeoffs are considerable.

 

[grepper]

I've wondered why I see so many videos of people cutting dry, even doing aluminum. I see it all the time. Maybe it's worth the trade-off. I would way rather just vacuum chips than deal with sludgy a mess.

Onion hand I tend to take Jim D.'s word as gospel, and feel lucky to have his erudite advice. He's been at this for awhile.

 

[TomS]

I've wondered why I see so many videos of people cutting dry, even doing aluminum. I see it all the time. Maybe it's worth the trade-off. I would way rather just vacuum chips than deal with sludgy a mess.

Onion hand I tend to take Jim D.'s word as gospel, and feel lucky to have his erudite advice. He's been at this for awhile.

I have flood coolant and a full enclosure with wash down on my machine. Clean up is not that difficult. When I'm done machining I wash the enclosure interior and vacuum up the chips. Done! I'm relatively new to CNC and maybe a bit naive but I find it easier to clean up the CNC mill over my manual mill with no enclosure.

Tom S.

 

[Firebrick43]

Were I work we have several hundred large 4 5 and 6 axis machines as well as dozen large surface grinders and 2 dozen 25' crank grinders. 95% of then are on water based coolant and a few deep hole drills on oil.

We find flood coolant pretty worthless from the cutting point of view. Low pressure systems are 60 psi. High pressure thru coolant is adjustable and can be a 1000 psi. Now this is for carbide and 20 to even 200 hp spindles.

The flood coolant is mostly for chip evacuation.

Con to flood coolant is rust. If you move and use the machine every day nothing happens, but during 2-3 week shutdowns or if operator leave the grinder tail stocks setting in one setup position rust problems can get bad and expensive. Coolant is mostly centralized but some machines is stand alone. The coolant is checked everyday on the main systems and weekly on the stand alone.

On some of the non production machines such as the tool room lathe the coolant can turn acidic and is not worth it in my opinion. Eats glass scales. Also water many times get past seals and reeks hell in servos, bearings, hydraulic systems, and gearboxes.

The oil systems don't have any of these issues but the oil is very expensive, nasty to be around let alone work in(feel greasy at the end of the day just setting by it) and fire is a real hazard.

Burn up a tool on a machine without load monitoring and you are not there quickly she can light up and is hard to put out. Many small shops can't use it as they can afford the insurance rates.

We even cut dry on some milling cutters (indexable carbide or ceramic)
Ceramics especially can't handle the shock cooling. Most of our slant beds also cut dry

From a home shop point I wouldn't mess will coolant as sometimes the machine will set for weeks without use. Also without tool detection and load monitoring the advantage of coolant over operator applied cutting oils is negated as the operator needs to be present at all times or nasty wrecks will occur.

 

[grepper]

several hundred large 4 5 and 6 axis machines as well as dozen large surface grinders and 2 dozen 25' crank grinders.

That's big!

home shop point I wouldn't mess will coolant as sometimes the machine will set for weeks without use. Also without tool detection and load monitoring the advantage of coolant over operator applied cutting oils

Both manual and CNC?

 

[Firebrick43]

Ya, there big but it's funny how size becomes what your used to. I can only imagine the size of machines that makes the big ship diesels.

Unless your home machine has a tool changer, tool probe, enclosure, spindle load monitor, and thru spindle coolant I would skip it on both.

I think a lot of people belive you can start a cnc machine and walk away. In a production environment you do. While your machine (or 2/3 machines) are running you are loading parts on pallets or a done machine, writing another program, or changing tools. These production type machines need all of the above needed items to work without constant at tension. Off your missing one or more of the listed items, you probably need to be there. If your there watching over the machine then why worry. When the program stops and you change tools the a brush/hook,or even shop vac clears chips. When your drilling or tapping a spray bottle or oil can can be used to apply cutting oil locally which is going to work better than flood coolant(not better than thru tool coolant however).

By all means if you have a vmc, hmc, or turning center have at a coolant system but I don't think you do if your posting here.

 

[grepper]

You could put my whole machine, a LMS 3990, in as a single tool in the tool holder of the stuff you are talking about. Sure seems like at least a good air stream to keep chips clear would be in order.

 

[Firebrick43]

An air wedge or accelerator nozzle would be nice to keep chips from building up in pockets and such.

48008 or 48002 nozzles from airtx use specially designed tips that use Venturi to draw surrounding air into the tip giving more power with much less air usage and much quieter. Make sure your put a regulator inline to adjust flow to just blow out around the tool and not send them intooblivion

 

[uncle harry]

That's some amazing SEM photography! Very cool to actually see what's happening. It would be inte

Really proves the case for coated cutters. I wonder what coating they mean, TiN?
CrN?

SEM is scanning electron microscopy done in high vacuum. I think the photographs are either directly from image displays or printed from digital signals according to my recollection. Please correct me if I'm in error here.