Tips/Techniques Coolant, the overlooked tool

[Former Member]

Watch and learn.

 

[jcdammeyer]

I wouldn't even dare take a cut that deep in one pass with or without coolant. Difference between a pro and an amateur I guess.

 

[phaxtris]

I think my whole mill would explode if I tried a cut like that

 

[Former Member]

My cuts aren't that aggressive either, don't have a 100hp spindle.

But aggressive cutting upto 0.100 depth, full cutter 1/2", 3000rpm, at 20IPM I have done with flood cooling and a 2hp (VFD) mill (it was accidental typically max is 0.050 depth). Without coolant chips aluminium chips fuse into the cutter bringing the machine to a halt.

Now is only I could get a 100hp high speed spindle onto my machine

 

[jcdammeyer]

My cuts aren't that aggressive either, don't have a 100hp spindle.

But aggressive cutting upto 0.100 depth, full cutter 1/2", 3000rpm, at 20IPM I have done with flood cooling and a 2hp (VFD) mill (it was accidental typically max is 0.050 depth). Without coolant chips aluminium chips fuse into the cutter bringing the machine to a halt.

Now is only I could get a 100hp high speed spindle onto my machine

Look outside at your power pole. One wire or three? Without power line provided 3 phase likely your 100HP is a non-starter. Now if you have enough space for a really long treadmill and can grow enough food for 100 horses I then stand corrected........

 

[phaxtris]

I got the solution to that problem ! Lol

 

[jcdammeyer]

I got the solution to that problem ! Lol

View attachment 29874

And it's on sale!

 

[phaxtris]

And it's on sale!

I mean if that's not enough reason I don't know what is !

 

[Dan Dubeau]

Somewhere around here I have a 1/2" EM that has a "splash" of aluminum welded to it. It looks like it was dropped in molten aluminum and the splash solidified. Had it on my desk for years, but can't find it right now. It was a great reminder to check the coolant levels before trying to rip some pockets in tooling plate........

Coolant helps. Not only for cooling and lubricating the tool, but for chip evacuation. I suspect the EM in the video would have made it with a simple air blast to help evacuate chips. Guess we'll never know. BOOOOOOM.

 

[Former Member]

I have used mist cooling and while good just doesn't compare to flood cooling.

On mist cooling parts come out hot, on flood they are still cool. On flood cooling I am still surprised how much evaporation occurs based on tops ups required to keep coolant levels correct. I also seem to get way better cutter life on flood cooling.

 

[little ol' e]

Looks to me like they used a 6 flute endmill on the first go, then, used a 4 flute vari-mill endmill to pull it off.
Not a good test IMO, but hey, its on you tube so coolant is the way to go.
I will stick to milling with good coatings and air, all day long....

 

[Former Member]

Looks to me like they used a 6 flute endmill on the first go, then, used a 4 flute vari-mill endmill to pull it off.
Not a good test IMO, but hey, its on you tube so coolant is the way to go.
I will stick to milling with good coatings and air, all day long....

Wait till you start pushing the cuts on longer runs or repetitive runs the heat builds up in your tooling will ultimately catch you, coatings or not. Cooling ultimately becomes the big issue. You'll note when you see Titans of CNC you are seeing less coatings than previous years. The reason for this is cost of sharpening as coating need to be removed and re-applied when cutters are sharpened. The second is coatings are very application specific, use the wrong coating and you'll actually cause more problems you need to deal with.

 

[LenVW]

The other nice thing about FLOOD cooling is the fact that material buildup in the tool path is non-existent because all the cuttings are flushed from the area and minimizes the chance of additional friction and cutter wear caused by the cutting debris.

 

[little ol' e]

Wait till you start pushing the cuts on longer runs or repetitive runs the heat builds up in your tooling will ultimately catch you, coatings or not. Cooling ultimately becomes the big issue.

We don't have any issues with heat build up when using carbide with air on the mills. With a good speed, feed and chip load, the heat is in the chip, not the tool or workpiece.
If you are generating too much heat, the problem isn't with your tooling.

 

[little ol' e]

You'll note when you see Titans of CNC you are seeing less coatings than previous years.

I suppose, they are much more advanced in the machining world?

 

[Former Member]

Me thinks you need to do a bit of research and reading to get updated on whats going on in the machining world.

Top CNC machines are running upwards of 1000psi or more coolant pressure, beside chip removal it provides maximum cooling.

In terms of coatings, incorrect coatings used in the wrong materials cause fusion during machining. I've experienced thus with Aluminium as most coatings contain Aluminium Oxide or Aluminium Nitrate. The best solution is to not to use coatings as it gives you the flexibility to use the same cutter on all materials, particularly important for a small hobby shop to keep the costs in line.

As to heat if you aren't generating it during cutting you ain't maximizing the performance of the machine.

Remember in any shop that is for business, cycle time per part is what makes money and reduces costs, the faster, more parts with the least wear on tooling the more money you make.

 

[little ol' e]

Wait till you start pushing the cuts on longer runs or repetitive runs the heat builds up in your tooling will ultimately catch you, coatings or not.

This is where advanced coatings along with Exocarb come into the equation.
I've left machine's running finishing toolpaths in 3D overnight.
Hardened A2/ D2 with a 2flute 1/2 ball nose. Using a .012 stepover with a uniform .02 stock over the surface with air.
No polishing required afterwards.
You couldn't do that with coolant.
Well you could, but, it just wouldn't make any sense really, or would it??

 

[Former Member]

Material, RPM, feed, tool dia, HP of machine? Interesting to see what speeds you are running.

I looked at their specs, funny thing is they don't fully define their coating but based on the applications chart it is a likely a Ti/Al Nitrate oxide, which in those material it is only rated as good. Fusion issues during cutting.

Bare carbide is a lot better in those materials.

 

[little ol' e]

Me thinks you need to do a bit of research and reading to get updated on whats going on in the machining world.

In terms of coatings, incorrect coatings used in the wrong materials cause fusion during machining. I've experienced thus with Aluminium as most coatings contain Aluminium Oxide or Aluminium Nitrate. The best solution is to not to use coatings as it gives you the flexibility to use the same cutter on all materials, particularly important for a small hobby shop to keep the costs in line.

Sounds good. I will try your best solution in Aluminum.
What type or uncoated carbide endmills are you using? How many flutes? Helical ? Variable flute?

 

[Former Member]

Currently straight helical 4 flute for the most part as they are readily available (and I use them on other things besides Al on occasion).

I'm guessing you are likely using a relative slow feed to get the finish (and in part allows no cooling), if you have cooling use it and finish quality will improve. For roughing pick up the speed (a lot) and you'll find cooling becomes your best friend.

Difference between no cooling runtime and cooling run time can be anywhere 5 to 20 fold difference time wise depending on application.

Finish cuts are a different animal, they take what they take to get the desired finish.