AIR BLAST For Steel Milling
 

I was milling some parts yesterday on the Hurco. Some steel parts. I
was using AlTin coated carbide mills. The parts looked ok, and the
chips looked good. Mostly blue with a few silver chips. The parts were
not getting excessively hot, but after a while I could see a dull glow
coming off the mill. That kind of bothered me so I setup and air blast.
That had the added benefit of eliminating chip recutting. The thing
is to get everything I anted the air blast had to use a modestly decent
volume of air. The parts actually looked better and mills never reached
that glow again, even with long cut times.

Is an air blast like that common for cutting steel? Remember I have
been CNC machining for more than a couple years now, but 99% of the
parts I make are aluminum. Years ago I used to come on this group and
pester you folks about cutting aluminum parts faster and faster and more
efficiently.

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently. I have dismissed vortex tubes out of hand. I
have made one, and I have a commercial one, and they both waste a lot
more air than any benefit they might provide. Heck, you get some
cooling affect as the air expands out of any nozzle. I was actually
thinking about things like a better nozzle design on the air blast to
get a predictable cone of air, and making a ball mount with a slip clamp
to hold the air nozzle so it can be directed to exactly surround the tip
of the mill with its cone of air.

AIR BLAST For Steel Milling
 

On Thursday, September 26, 2019 at 11:46:29 AM UTC-4, Bob La Londe wrote:




If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently.

I would think using the ail to blow a mist would be a lot more efficient. But understand that mist might not be good thing with carbide.

Maybe use a hypodermic needle to use less air but direct the air better.

Dan

AIR BLAST For Steel Milling
 

On 9/27/2019 6:05 AM, wrote: On Thursday, September 26,
2019 at 11:46:29 AM UTC-4, Bob La Londe wrote:




If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently.

I would think using the ail to blow a mist would be a lot more
efficient. But understand that mist might not be good thing with carbide.

Maybe use a hypodermic needle to use less air but direct the air better.

Dan



Well, something along those lines, but I think that would not be nearly
enough air to be useful. Even the nozzle from an irrigating syringe
might be a little small.

AIR BLAST For Steel Milling
 

On Thu, 26 Sep 2019 08:46:26 -0700, Bob La Londe
wrote:

I was milling some parts yesterday on the Hurco. Some steel parts. I
was using AlTin coated carbide mills. The parts looked ok, and the
chips looked good. Mostly blue with a few silver chips. The parts were
not getting excessively hot, but after a while I could see a dull glow
coming off the mill. That kind of bothered me so I setup and air blast.
That had the added benefit of eliminating chip recutting. The thing
is to get everything I anted the air blast had to use a modestly decent
volume of air. The parts actually looked better and mills never reached
that glow again, even with long cut times.

Is an air blast like that common for cutting steel? Remember I have
been CNC machining for more than a couple years now, but 99% of the
parts I make are aluminum. Years ago I used to come on this group and
pester you folks about cutting aluminum parts faster and faster and more
efficiently.

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently. I have dismissed vortex tubes out of hand. I
have made one, and I have a commercial one, and they both waste a lot
more air than any benefit they might provide. Heck, you get some
cooling affect as the air expands out of any nozzle. I was actually
thinking about things like a better nozzle design on the air blast to
get a predictable cone of air, and making a ball mount with a slip clamp
to hold the air nozzle so it can be directed to exactly surround the tip
of the mill with its cone of air.
Air blast is indeed used for metal cutting. It not only removes chips
but can keep the cutting tool cooler. This helps prevent chip welding.
A cooler chip will often break sooner too, resulting in smaller chips.
Eric

AIR BLAST For Steel Milling
 

"Bob La Londe" wrote in message ...

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently.

No direct experience, just a comment from the peanut gallery. I don't think
this air would need to go through your dryer, just use one of those water
trap/pressure regulators at your mill installed just after a low spot with a
drain valve.

--
Regards,
Carl Ijames

AIR BLAST For Steel Milling
 

On Fri, 27 Sep 2019 09:19:22 -0700, Bob La Londe wrote:
On 9/27/2019 6:05 AM, wrote: On Thursday, September 26,
2019 at 11:46:29 AM UTC-4, Bob La Londe wrote:
If an air blast is useful for that sort of thing, what can I do to
use the air more efficiently.

I would think using the ail to blow a mist would be a lot more
efficient. But understand that mist might not be good thing with
carbide.

Maybe use a hypodermic needle to use less air but direct the air
better. Dan

Well, something along those lines, but I think that would not be nearly
enough air to be useful. Even the nozzle from an irrigating syringe
might be a little small.

Other nozzle possibilities include mig welding tips, plasma cutter
nozzles, and 3D printer extruder nozzles. The latter come in a
nice range of sizes. For example, an Amazon $9.99 set of 28 has
2x0.2mm, 2x0.25mm, 2x0.3mm, 2x0.35mm, 10x0.4mm, 2x0.5mm, 2x0.6 mm,
2x0.8mm, 2x1.0 mm. A $3.22 ebay set (19pcs MK8 Extruder Nozzle)
has 2x0.2mm, 2x0.3mm, 7x0.4mm, 2x0.5mm, 2x0.6 mm, 2x0.8mm, 2x1.0 mm.
Those sets are all in brass. Hardened steel and ruby tip 3D nozzles
also are available, costing about 10 times as much.

Regarding your air dryers, does the air blast need to be dry? If
not you could plumb its air out beforehand, presumably lessening
the dryer load.

--
jiw

AIR BLAST For Steel Milling
 

"Bob La Londe" wrote in message
...
On 9/27/2019 6:05 AM, wrote: On Thursday, September
26, 2019 at 11:46:29 AM UTC-4, Bob La Londe wrote:




If an air blast is useful for that sort of thing, what can I do
to use
the air more efficiently.

I would think using the ail to blow a mist would be a lot more
efficient. But understand that mist might not be good thing with
carbide.

Maybe use a hypodermic needle to use less air but direct the air
better.

Dan



Well, something along those lines, but I think that would not be
nearly enough air to be useful. Even the nozzle from an irrigating
syringe might be a little small.

I made a convergent nozzle to experiment with air flow amplification
by reaming the nozzle conical with a tapered D reamer. The reamer is a
lathe turned 20 degree steel cone milled lengthwise to the D
cross-section, and ground sharp, and the tip ground to a drill bit
shape.The aluminum nozzle blank was step-drilled before reaming
because the reamer doesn't cut freely, it has to be forced in.

Th outside of the nozzle is a somewhat steeper taper so it doesn't
impede air drawn into the exit jet. I reamed it larger until I liked
the result.

AIR BLAST For Steel Milling
 

On 9/26/2019 8:46 AM, Bob La Londe wrote:
I was milling some parts yesterday on the Hurco.Â* Some steel parts.Â* I
was using AlTin coated carbide mills.Â* The parts looked ok, and the
chips looked good.Â* Mostly blue with a few silver chips.Â* The parts were
not getting excessively hot, but after a while I could see a dull glow
coming off the mill.Â* That kind of bothered me so I setup and air blast.
Â*That had the added benefit of eliminating chip recutting.Â* The thing
is to get everything I anted the air blast had to use a modestly decent
volume of air.Â* The parts actually looked better and mills never reached
that glow again, even with long cut times.

Is an air blast like that common for cutting steel?Â* Remember I have
been CNC machining for more than a couple years now, but 99% of the
parts I make are aluminum.Â* Years ago I used to come on this group and
pester you folks about cutting aluminum parts faster and faster and more
efficiently.

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently.Â* I have dismissed vortex tubes out of hand.Â* I
have made one, and I have a commercial one, and they both waste a lot
more air than any benefit they might provide.Â* Heck, you get some
cooling affect as the air expands out of any nozzle.Â* I was actually
thinking about things like a better nozzle design on the air blast to
get a predictable cone of air, and making a ball mount with a slip clamp
to hold the air nozzle so it can be directed to exactly surround the tip
of the mill with its cone of air.





I wonder if it would be worth it to use a venturri at the nozzle to
increase air volume.

AIR BLAST For Steel Milling
 

On Sunday, September 29, 2019 at 10:59:00 AM UTC-7, Bob La Londe wrote:

I wonder if it would be worth it to use a venturri at the nozzle to
increase air volume.

Yes, and if you can tap the compressor tank BEFORE the regulator, it certainly
will be more efficient. The high airspeed from full pressure air is not
required, but throttling the pressure is a waste of energy/compressor
power. It'll be a trifle noisy, though; consider earplugs.

Lots of airguns use venturis (venturae?) anyhow, you might just find a suitable
nozzle off-the-shelf.

AIR BLAST For Steel Milling
 

On 9/29/2019 3:11 PM, whit3rd wrote: On Sunday, September 29, 2019 at
10:59:00 AM UTC-7, Bob La Londe wrote:

I wonder if it would be worth it to use a venturri at the nozzle to
increase air volume.

Yes, and if you can tap the compressor tank BEFORE the regulator, it
certainly
will be more efficient. The high airspeed from full pressure air is not
required, but throttling the pressure is a waste of energy/compressor
power. It'll be a trifle noisy, though; consider earplugs.

Lots of airguns use venturis (venturae?) anyhow, you might just find
a suitable
nozzle off-the-shelf.


Actually I have a venturi vacuum pump I was thinking about repurposing.

However routing a new line all the way around the shop and thru the
machine room is not a quick short term answer as discussed in other posts.

AIR BLAST For Steel Milling
 

On Thu, 26 Sep 2019 08:46:26 -0700, Bob La Londe
wrote:

I was milling some parts yesterday on the Hurco. Some steel parts. I
was using AlTin coated carbide mills. The parts looked ok, and the
chips looked good. Mostly blue with a few silver chips. The parts were
not getting excessively hot, but after a while I could see a dull glow
coming off the mill. That kind of bothered me so I setup and air blast.
That had the added benefit of eliminating chip recutting. The thing
is to get everything I anted the air blast had to use a modestly decent
volume of air. The parts actually looked better and mills never reached
that glow again, even with long cut times.

Is an air blast like that common for cutting steel? Remember I have
been CNC machining for more than a couple years now, but 99% of the
parts I make are aluminum. Years ago I used to come on this group and
pester you folks about cutting aluminum parts faster and faster and more
efficiently.

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently. I have dismissed vortex tubes out of hand. I
have made one, and I have a commercial one, and they both waste a lot
more air than any benefit they might provide. Heck, you get some
cooling affect as the air expands out of any nozzle. I was actually
thinking about things like a better nozzle design on the air blast to
get a predictable cone of air, and making a ball mount with a slip clamp
to hold the air nozzle so it can be directed to exactly surround the tip
of the mill with its cone of air.

Whats your flow on your coolant pump? I suspect you would be far far
better off hooking up a bigger pump and having multiple nozzels.
Also...pay attention to feed rates and mill tooth counts. If you are
not getting the chip out just after the cut and it goes around and
around a time or two..you will get heat and reduced flute life. Some
endmills are cut for good chip clearance..others..not so much.

Aluminum has no limites on feed rates if you have the rpms..steels
certainly do. Blow that chip out with a good strong coolant pump.

Gunner
__

"Poor widdle Wudy...mentally ill, lies constantly, doesnt know who he is, or even what gender "he" is.

No more pathetic creature has ever walked the earth. But...he is locked into a mental hospital for the safety of the public.

Which is a very good thing."

Asun rauhassa, valmistaudun sotaan.


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

AIR BLAST For Steel Milling
 

On 9/26/2019 8:46 AM, Bob La Londe wrote:
I was milling some parts yesterday on the Hurco.Â* Some steel parts.Â* I
was using AlTin coated carbide mills.Â* The parts looked ok, and the
chips looked good.Â* Mostly blue with a few silver chips.Â* The parts were
not getting excessively hot, but after a while I could see a dull glow
coming off the mill.Â* That kind of bothered me so I setup and air blast.
Â*That had the added benefit of eliminating chip recutting.Â* The thing
is to get everything I anted the air blast had to use a modestly decent
volume of air.Â* The parts actually looked better and mills never reached
that glow again, even with long cut times.

Is an air blast like that common for cutting steel?Â* Remember I have
been CNC machining for more than a couple years now, but 99% of the
parts I make are aluminum.Â* Years ago I used to come on this group and
pester you folks about cutting aluminum parts faster and faster and more
efficiently.

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently.Â* I have dismissed vortex tubes out of hand.Â* I
have made one, and I have a commercial one, and they both waste a lot
more air than any benefit they might provide.Â* Heck, you get some
cooling affect as the air expands out of any nozzle.Â* I was actually
thinking about things like a better nozzle design on the air blast to
get a predictable cone of air, and making a ball mount with a slip clamp
to hold the air nozzle so it can be directed to exactly surround the tip
of the mill with its cone of air.



Side Note: I setup an old Venturi vacuum pump on a magnetic base for
some steel milling on my middle weight CNC mill and it worked great.
Work piece came off the machine barely warm after an hour of cutting.
Same with the mill. Lots of blue chips. I had a pretty good stream of
air, but the compressor didn't cycle on as often as with my straight
pipe air blast. Both have a ball valve for flow control. Now to look
at redirecting that vacuum port to reduce likelihood of picking up chips...

AIR BLAST For Steel Milling
 

"Bob La Londe" wrote in message
...
On 9/26/2019 8:46 AM, Bob La Londe wrote:
..
If an air blast is useful for that sort of thing, what can I do to
use the air more efficiently. I have dismissed vortex tubes out of
hand. I have made one, and I have a commercial one, and they both
waste a lot more air than any benefit they might provide. Heck, you
get some cooling affect as the air expands out of any nozzle. I was
actually thinking about things like a better nozzle design on the
air blast to get a predictable cone of air, and making a ball mount
with a slip clamp to hold the air nozzle so it can be directed to
exactly surround the tip of the mill with its cone of air.

Side Note: I setup an old Venturi vacuum pump on a magnetic base
for some steel milling on my middle weight CNC mill and it worked
great. Work piece came off the machine barely warm after an hour of
cutting. Same with the mill. Lots of blue chips. I had a pretty
good stream of air, but the compressor didn't cycle on as often as
with my straight pipe air blast. Both have a ball valve for flow
control. Now to look at redirecting that vacuum port to reduce
likelihood of picking up chips...


You can use these tapered drill bits to make internally and externally
tapered nozzles like I described, which are more efficient if you
gradually open up the bore to allow only as much air flow as you need
at full air line pressure, without an energy-wasting throttling valve.
https://www.amazon.com/Tapered-Drill.../dp/B0007UQ2FK

The external taper helps draw outside air into the flow, somewhat like
the venturi aspirator but simpler to make.