[pickled]

I just thought that I would pass along some info on some tooling that is working well with my 1100 and 770's for cutting tough gummy materials. I had previously used Accupro and Kennametal carbide end mills for my work and have had great results. I bought a few of these Destiny Tool Raptor DVH series end mills to try out a couple months ago and I am pretty impressed with their performance. Anyway, I had to cut some 1/8" titanium sheet/plate for a project yesterday and the motor on my import band saw finally went up in smoke. NBD- it has paid for itself over the years at least 10 fold so I am just going to celebrate its life and retrofit a donor.

Well I had to get this material cut and I hate using a cut-off wheel on Titanium. I also didn't want to use the plasma due to warpage issues and HAZ possibly inducing later structural problems. This basically left me with the option of running 1 foot long slots to get my 2.25" x 12" stock profile. Wanting to balance efficiency with kerf loss (Certified Ti is stupid costly) I just grabbed the 1/4" EM that I had used for profiling my last stainless job. I calculated the feeds using the OEM's data and opted for a slightly below mid-range SFM. The results made me quite happy! This little end mill slotted 15 feet of 0.125" Ti and is still in great shape. My 770 had no resonance to speak of.

If anyone cares to see the cutter in action I have some rather marginal quality camera and lighting work that shows footage of the 13th and 14th slots. The initial cost of these end mills is a little up there, but I'm not going to complain if I can keep getting performance that is pretty rock solid in challenging materials. For those of you that choose to watch I hope that you don't mind my tired ramblings and occasional shakes. I have 2 other cameras that I am moving into the work area so I can document my projects better. This camera is shot and the focus adjustment has a mind of its own.

https://youtu.be/t2d02DZfRBI:cheers:

[EvolveES]

This is really cool to see. It is always encouraging to see the capabilities of these machines pushed beyond the typical materials. I have a 304 stainless job coming up so in the next few weeks i hope to bet that down. I will be trying the high speed machining approach first. Thanks for sharing what you found out

[pickled]

Glad that you found some value in seeing the material get cut. At > $1.50 per square inch any non-needed stock reduction really starts to add up on this job. Thankfully my band saw is back in business. By the way HSM for pocketing works very well in SS. I try not to ever run any straight slots because it is just a way of begging for trouble in 304 and 316. Be sure to use the shortest end mills that you need to get the job done.

I rarely run more than 30 or 40 of the same items in any one set-up. Learning how to use these machines to work with difficult materials really allows us to be competitive in a lot of non-traditional areas. Once the bulk material removal is over even the big guys have to run slower. The material will not allow for high IPT or SFM so once you find your way into the sweet spot of feeds and speeds you have arrived. Basically I see 85% of the winning formula for subtractive prototyping to be fixturing and matching tooling/feeds and speeds to the materials at hand. Vast amounts of HP and insane rapids are a luxury item that I am not willing to pay for at this point in time for my needs.

[EvolveES]

Thanks for the pointers on the Stainless, The parts i will be making are very low tolerance and very shallow cuts (probably around 0.05" deep relief areas) and some drilled holes. The whole thing kind of scares me so i am going to get lots of spare tools to support the learning curve. And good point on the speed of the bigger machines, i know a guy with a 7HP Bridgeport VMC and he always complains about having to run stainless and cast iron slow anyway. I really think the Tormach is a great value and with my experience (newbie) it has all the HP i need right now. I have enjoyed all of the learning and i take it as a challenge to learn to do all of the difficult materials, titanium is on the list too and now i don't feel so scared after seeing how well your 770 did.

[pickled]

Thanks for the pointers on the Stainless, The parts i will be making are very low tolerance and very shallow cuts (probably around 0.05" deep relief areas) and some drilled holes. The whole thing kind of scares me so i am going to get lots of spare tools to support the learning curve. And good point on the speed of the bigger machines, i know a guy with a 7HP Bridgeport VMC and he always complains about having to run stainless and cast iron slow anyway. I really think the Tormach is a great value and with my experience (newbie) it has all the HP i need right now. I have enjoyed all of the learning and i take it as a challenge to learn to do all of the difficult materials, titanium is on the list too and now i don't feel so scared after seeing how well your 770 did.

FYI the hardest part for your upcoming job will most likely be drilling the holes. I'd advise you to buy a couple screw machine length cobalt twist drills of the sizes that you need. Feed heavier than you think that you need to. Stainless does not appreciate being drilled or milled with light feeds and will kill your tooling in a second if you don't respect its wishes! If it work hardens on you you are in trouble:drowning:. Flood coolant or cutting oil is a must with this material for drilling of any depth. The same applies to drilling Titanium. Titanium is my favorite material to machine BTW. The chips and swarf clean up so easily and any necessary hand deburring work is a piece of cake. I don't like welding it though because I have to either use a massive trailing shield, or do it in a chamber flooded with Argon. It's a PITA and you blow through a typical month's worth of Argon in a day.

[EvolveES]

Thanks again, that's good to know, my first experience with 304 was not a good one, it was 3/8" thick material and i was making a throttle body mount for a friend. I snapped a Q size HSS drill on the first hole. Ruined two brand new 3/8" SGS Z-Carb coated end mills too. I have read about the work hardening and tried to go heavy on the feeds, but i guess it wasn't enough. I'm gonna try this round with the cobalt drills you mentioned in the screw length, and holding them in collets not drill chucks. The milling i will try with 1/4" coated carbide end mill and using the high speed method with very shallow cuts with small step over. the Youtube video i have seen doing this worked beautifully i just hope i can replicate that. I have often heard that 304 is worse than titanium because of the work hardening. If all goes well i will probably post on here with the results and what i found to work well.

[pickled]

Yes 300 (besides 303) and 400 series stainless steels are much harder to turn and machine than titanium. If you didn't see the video I had up on the Youtube channel of helical machining 1" 304 it shows the speeds, feeds, depth of cut and width of cut that I have found work for me on my PCNC 1100. I listed these out in the description that you can read without watching the whole video. I was using a TiALN coated Kennametal 4 Flute carbide end mill, but have had success with other brands too. I hope to read about your successful project on here soon. Here's a link to that stainless video. https://youtu.be/0-HNJv8qyd0

[CadRhino]

That was educational. Thanks for posting the video

Yes 300 (besides 303) and 400 series stainless steels are much harder to turn and machine than titanium. If you didn't see the video I had up on the Youtube channel of helical machining 1" 304 it shows the speeds, feeds, depth of cut and width of cut that I have found work for me on my PCNC 1100. I listed these out in the description that you can read without watching the whole video. I was using a TiALN coated Kennametal 4 Flute carbide end mill, but have had success with other brands too. I hope to read about your successful project on here soon. Here's a link to that stainless video. https://youtu.be/0-HNJv8qyd0

[EvolveES]

That is great, thanks for the video. Now i have seen 304 done both ways on a PCNC 1100, i have seen youtube videos of high speed machining approach, and with yours i have seen a more traditional deeper depth and width approach (which i did not think was possible with the Tormach until i saw your video). I am curious to try for myself, the material is here and i will probably start soon, i'm nervous on the cost amount of broken tools it will take for me to get it down lol. Thanks again.