[dlange]

Alright
I haven't had much luck with these calculators from different websites, Take your pick, american machinest, Gwizard.. so on

The machine I use reads in IPR along with RPM

To have a nice finish I've come to such conclusions as

For example with 6061 Aluminum
cutting through a thickness of .135" with one pass for nice finish works to
850 IPM 14K RPM single flute. which give me an IPR of .061

cutting through a thickness of .350 with one pass, milling out ward
same.. one pass for nice finish works out to
2800 IPM 14K RPM single flute. which gives me an IPR of .2

My question.. Are these IPM numbers irregular? Are the RPMs irregular. I'm trying to see if I'm doing something wrong or missing something.

Thank You!

[christinandavid]

Are you saying you are feeding at .2" (5mm) per revolution with a single-flute cutter?

5 cuts per inch in other words. That is an amazing tool if it is giving a good finish.

DP

[dlange]

yes that is correct. I can go slower and get a good finish but its not shiny, its not reflective at all.. almost like the aluminum chips just push themselves into the cut. I am completely new to this.

I have learned quickly that speeds and feeds are one of the hardest things to figure out in this CnC world. I some how have to go fast enough to where the cutter isn't going to break, there isn't a lot of vibration, and a clean, reflective finish is left over.
Here is a picture of the tool


I believe in this picture an 8mm is shown, I'm currently using a 12mm same style.

PEACES!

[christinandavid]

What is the traverse range of the machine?

DP

[dertsap]

the best thing to do is contact the tool manufacturer and get their recommended feeds and speeds

[dlange]

I want to say traverse range is 24 inches but I could be wrong.. I mean, I am a total newb with a tape measure.

Dertsap.. already done it, awaiting the e-mail :-)

[christinandavid]

So, is that the range in X, Y or Z? What is the largest job the machine can do? Just give us a rough estimate in all three axes.

DP

[dlange]

Looking at 141 inches for X axis, 24 inches for Y axis, and 24 inches for Z axis

And I just cut with a 2 flute helical downcut 3/8 end mill, what a beautiful shine ran it at 15k RPM with .133 IPR feed

[dlange]

I'm still not 100% comfortable with these speeds and feeds because I run over to the tool after the cut and feel it, and there is quite a bit of heat staying with the tool, so thats telling me the heat isn't staying with the chip.. same 15K RPM .133 IPR feed

[christinandavid]

So - from corner to corner of your X Y traverse is 143 inches.

You are feeding at: - 15000 revs per minute x .133 inches per revolution = 1995 inches per minute.

Your cutter will feed from one corner to the opposite corner in 4.3 seconds.

Does that sound right?

DP

[dlange]

Right now I'm just cutting circles out of aluminum.. Would it go corner to corner in 4.3 seconds.. that sounds about right, its moving pretty quick while cutting
My day is over, talk to ya'll tomorrow bright and early!

-D

[dertsap]

thats going to be a mighty large chip/tooth

[christinandavid]

It does seem rather excessive - or am I that far behind the times?

DP

[dertsap]

that would be nearly .034"/tooth on a 4 flt at .133 in/rev , that's beyond anything I've ever seen . I'd usually suggest .007-.013/tooth on quality aluminum cutting carbides , anything more tends to be quite destructive

[christinandavid]

Remember it's a 1 or 2-flute being used... on a finish pass the cutter would survive at that feed but I can't see the finish being too smart (akin to 'forgetting to put a G1 in')

dlange...I'm not convinced we are talking the same language here....please time a full length linear move and let us know what speed/feed figures you inputted into the control.

Cheers,

DP

[dlange]

When traveling 10 inches from the moment the tool starts moving in X axis..
10 inches
Feed 1 (IPR)
RPM 1000
Time: 60 Seconds

Feed 10 (IPR)
RPM 1000
Time: 6 seconds

Feed 1 (IPR)
RPM 10000
Time: 6 seconds

I hope that helps. If someone knows a G code for full length linear move please let me know.

You guys know what you are doing and know the lingo, I'm starting to pick it up, but its pretty much Goo Goo Ga Ga until I get down the basics.
Sorry for the confusion, I'm New!!! A newb!

[Gabe Newell]

Well, slotting .135" 6061 aluminum with a single-flute 12 mm (.4724") cutter, I'd probably go 790 SFM/6392 RPM. For a feedrate I'd go 24.157 IPM. The IPR would be .0038 (which is the same as the Inch Per Tooth as you have a single-flute tool).

If I were constrained to run at 14K RPM, that's 1731 SFM. I'd keep the IPR/IPT the same at .0038, or a feedrate of 52.909.

Going to Lakeshore Carbide, for their variable 3 Flute, ZRN coated tool they suggest 1900-2000 SFM for slotting at 50% DOC, so my numbers would be conservative compared to that tool. With a single-flute 12 mm tool you'd have to hit 15,364 RPM to get to 1900 SFM (and your feedrate would be 58.064 IPM with a .0038 IPT/IPR).

http://www.lakeshorecarbide.com/lake...raluminum.aspx

However your tool appears to be uncoated, so both your feed per revolution and your RPMs appear to be quite aggressive.

If the spindle runs at one speed (14K RPM), then you'd need to go down to .25"/~6mm tool to have a SFM under 1000. At that point your feedrate would be ~27 IPM, and your IPR/IPT would be .002.

[Gabe Newell]

I checked Micro100's speeds and feeds for single flute end mills in aluminum.

They suggest 656-1476 SFM, and .0002" - .0039" IPT/IPR. The range (over 10x) on IPR surprised me.

You can download their spreadsheet at:
http://www.micro100.com/downloads/MI...art_042004.xls

This is cutting with coolant.

Using their most aggressive numbers for both speed and feed, you'd get 11935 RPM, 46.548 IPM (using 1476 SFM and .0039 IPT/IPR).

[dlange]

The slowest I've ran this thing was .047 Feed (IPR) and garsh that was dead slow.

New Tool 2 flute 3/8 end mill, just playing around with this here and got lucky

15K RPM .133 Feed (IPR)
This was done with a one pass, milling out option, not sure of the terminology, where the tool starts near the middle then spiral cuts its way outward to the diameter. The cuts sounds rather agressive but no hang ups.. how can I argue with a shine like that! I would like to have less heat with the tool though.

The holes about were done with the single flute 12mm

[Gabe Newell]

In order to get to 2800 IPM at a .0038 IPR, you'd need a spindle that could reach 736,842 RPM and a coating that could withstand 91368 SFM in aluminum.