How hard do you press your tormach thru mild steel?

[CncForMe]

Curious about your experiences with speeds, feeds, and DOC on your mill. I usually run a 1/4 inch four flute TIALN carbide endmill @ 3500 rpm .1 DOC 7 IPM feed but i feel like i could go a lot harder, what do you think? Opinions on SS would be nice too. I know there are are calcs for this but i really want your thoughts.

[functionbikes]

With my machine I generally use a 3/8 carbide at 1500rpm and 10ipm with a depth of .06 in mild crs

[CncForYou]

As hard as the day is long...

[tobyaxis]

Your best bet is to gradually increase both the Speed and Feed equally in increments of 5% to 10% to see how it does.

Speed and Feed can vary from a few different variables which are but not limited to:

Machine Rigidity
Machine Wear
Machining Operation
Tool Length
Tool Material
Tool Coating
Tool Quality
Tool Condition (New or Used)
Set-Up Rigidity
Work Holding
Work Material
and Temp

Listen too and feel what your machine can handle. You will find that results will vary a little or a lot depending on but not limited to the variables listed above.

Good Luck

Cheers!!!

[HMB3000]

with the Tormach the biggest issue between materails is the HP of spindle...you sometime can remove more materail in less time by using a smaller dia. tool with a deep cut depth...also when roughing a roughting tool will take a bigger cut than a staight flute tool as it needs less horse power to cut

[thackman]

All my projects have been in plastic and 6061 and I don't have flood cooling yet but there are two brackets that I've been wanting to cut out of some A36 that I have laying around. Since that tool is TIALN have you been running it dry? What type of tool life do you get? If dry do you have hot chips flying everywhere?

[tobyaxis]

Originally Posted by thackman All my projects have been in plastic and 6061 and I don't have flood cooling yet but there are two brackets that I've been wanting to cut out of some A36 that I have laying around. Since that tool is TIALN have you been running it dry? What type of tool life do you get? If dry do you have hot chips flying everywhere?

Well the goal is to remove the Heat from the work in the chip. So yes you will have hot chips flying. If you run a lower RPM with a good feedrate the distance that the chip flies will be less.

[thackman]

From what I've heard slowing down isn't good for TiALN. It's performance doesn't kick in till the chips get really hot. With such high sfms' they really spray everywhere. I was just looking for some feedback from someone with first hand experience.

[HMB3000]

do you have air? don't liston to Toby he only shows how little he knows about machining (on a Tormach)...by dropping RPM you increase tool and spindle load and build up heat in both. A-series will work harden real fast...you will want a shallow depth of cut and and fairly fast feed ...you can place a piece of plywood for a sheild (plix will just melt with hot chips)...

[Scott_M]

I am currently running a job in 12L14 ( Free machining steel )
Niagara 3/8" 4 flute TiAln
75% step over
S3500
F25
.075" DOC
And I am running it dry !
Really removes some material , flings chips pretty good. They aren't discolored and the work piece is just warm when done.
I am sure it could handle more but my setup is not very ridgid. It is hanging out of my 4th axis. Anymore feed or speed and I start to get some chatter.
If this was held in the vise I bet it would do F35 at S4000-4500.
The part is about 90% chips and I have gone through 12 feet of 1" bar on the same endmill. ( High quality endmills last much longer than the cheapies )

I love 12L14

Scott

[Coolster]

Originally Posted by Scott_M I am currently running a job in 12L14 ( Free machining steel ) Niagara 3/8" 4 flute TiAln 75% step over S3500 F25 .075" DOC And I am running it dry ! Really removes some material , flings chips pretty good. They aren't discolored and the work piece is just warm when done. I am sure it could handle more but my setup is not very ridgid. It is hanging out of my 4th axis. Anymore feed or speed and I start to get some chatter. If this was held in the vise I bet it would do F35 at S4000-4500. The part is about 90% chips and I have gone through 12 feet of 1" bar on the same endmill. ( High quality endmills last much longer than the cheapies ) I love 12L14 Scott

You need coolant.

[Scott_M]

Originally Posted by Coolster You need coolant.

I respectfully disagree. For a couple of reasons.

First off I am running this job in my 4th axis and with the amount of coolant being flung from an endmill going 3500 rpm it would fill up my rotary table. ( They don't have any seals ) I had to disassemble it once to clean it and re-lube. I don't want to do that again.
One of the big benifits from coolant is clearing chips away so they are not recut. The work flow on this job is very good and the chips are not an issue.
Carbide is pretty tough stuff and has amazing thermal properties. It is said that if you can not supply coolant in sufficent quanties...don't use it ! Thermal shock is a bigger danger to carbide than heat is.
Also as stated above after 10 minutes of heavy cutting the tool and work piece are just warm. So the heat is being ejected with the chips.
My finish is great so no problem there.
It is likely that I would get a bit more tool life with coolant but with all the added clean up it does not seem economical.
I am very pleased with the way the job runs.
Some pictures of the finished job HERE towards the bottom of the page.

Respectfully

Scott