Newbie- Tormach and Alloy Steel ?

[Need CNC]

I have pretty much narrowed my CNC choice down to the Tormach but I need to know a few things.


How well will this machine cut steel ? 4130, 4140, etc. [non HT] ?


I plan on cutting about 50% of my parts in 6061-T6/7075-T6 and 50% in 4000 series steel. Maybe even a sprinkle of stainless.


I would be machining from regular shape billet, no pre-cut custom shapes.


I know this machine will handle aluminum just fine but I am not so sure about its speed on steel.


Speed is not a huge concern, as I make very low-volume parts, but I need to know what to expect.


For the sake of argument, let's use an AR15 lower receiver for example. It is not what I will be making but it is a nice size and very curvy. If I put a block of 4140 in the machine, how long would it take to mill that down ? A week


I'm trying to wean myself off of subbing parts... so this will not directly impact what I already make.

Also, I would be going with the 4th axis [assuming it would work well with a decent size part].

Lastly, I use Solidworks and have access to Mastercam [if this makes any difference]. I am learning on some free CAM programs now and will buy a license when I find the right one.

Ask me anything that might help you help me.

Thanks !

[David Bord]

Ive heard reports of the machine cutting tool steel and exotic metals with little trouble. I think for the pricepoint you wont find a better machine. I have been cutting some 1020 lately and its cuts like butter using a .5" 4 flute carbide bit. half depth and width at about 14 ipm.

I dont have much experience with steel but Im sure others will pipe in...

David

[keen]

Hi - I do toolmaking on my tormach and work with toolsteel often.

Pic below is machined out of K600 tough to machine toolsteel. With this repeat job i take 1mm deep cuts with a 16mm 2 flute carbide insert cutter. Horsepower is the first limitation - but if you increased that then lack of rigidity would not be far behind.

The tormach is quite well balanced but you do need to plan carefully and be patient when working with toolsteel

[thum31]

Just last night i cut parts out of some 4140 and 4350. 1/4" end mill .375 depth of cut and .235 width of cut. 2150rpm 7ipm. Flood to move the chips. I used the 8 inch 4th axis as a fixture(vertical). I had not intended the width to be this much but it handled it great so I left the program alone. I have spent 2 0r 3 grand on endmills since I got the mill. I ruined most of them by going too slow and too shallow with the cut. By trying to save the tooling I was killing it quickly. I just changed my approach to programming a couple weeks ago. Since switching to the more aggressive technique I have not broken a tool.
I run 304,316, stainless, 718 inconel, and grade 5 titanium on the Tormach every week. It will handle anything if you program it for the setup and machine.
You have to stay inside the machines limitations, I just keep finding out the machine is not as limited as my programming creativity.

[David Bord]

Originally Posted by thum31 Just last night i cut parts out of some 4140 and 4350. 1/4" end mill .375 depth of cut and .235 width of cut. 2150rpm 7ipm. Flood to move the chips. I used the 8 inch 4th axis as a fixture(vertical). I had not intended the width to be this much but it handled it great so I left the program alone. I have spent 2 0r 3 grand on endmills since I got the mill. I ruined most of them by going too slow and too shallow with the cut. By trying to save the tooling I was killing it quickly. I just changed my approach to programming a couple weeks ago. Since switching to the more aggressive technique I have not broken a tool. I run 304,316, stainless, 718 inconel, and grade 5 titanium on the Tormach every week. It will handle anything if you program it for the setup and machine. You have to stay inside the machines limitations, I just keep finding out the machine is not as limited as my programming creativity.

Seriously, .375 depth right near full tooth width of .235 at 7ipm? That defies logic. Im no expert by any stretch, but that seems way above any of the guides Ive seen for steel

David

[thum31]

I programmed it to run the same .012 per pass as I use on stainless as a starting point. I did not take into account the starting diameter of the stock. Only the first pass around the part at .375 is cutting that much. The part is not round so I am only cutting that much on the x+, x- side the y+,y- is much more reasonable. The first lap around the part I realized what I had forgotten but it was cutting it just fine and as I said I just let it go. This is an outside contour op, I'm sure the end mill would have not handled it had it been a full width slot.

You can check my math, I may be missing something.
Finished part size is .900 wide. Starting stock is 1.4 (ish) I programmed it to take four passes. The first pass should be at .948. 1.4-.948=.452/2=.226 per side on the first pass. I would not have intentionally programmed it to cut even .100
So I guess i was off .010.

I spent months worrying over the purchase of this mill. Mainly with the same concerns as the O.P. Since I rarely cut Aluminum I was very concerned about the capabilities of the Tormach on stainless.

Almost all the parts I cut are proprietary so I can't post videos of the actual parts. Once I am caught up a little I think I will make a few vid's showing the increase in performance since adopting the concepts described in the article I linked in my first post. I'm glad I did not run it at the recommended 22.5 ipm, I know how that would have turned out.

[levelzero]

Originally Posted by David Bord Ive heard reports of the machine cutting tool steel and exotic metals with little trouble. I think for the pricepoint you wont find a better machine. I have been cutting some 1020 lately and its cuts like butter using a .5" 4 flute carbide bit. half depth and width at about 14 ipm. I dont have much experience with steel but Im sure others will pipe in... David

What rpm were you running? Do you use the TTS?

[David Bord]

Originally Posted by levelzero What rpm were you running? Do you use the TTS?

about 2000-2200. Yes, I use the TTS with a setscrew holder, no flat on the EM. I think I could go even faster IPM. At the 14ipm it seems almost effortless.

David