Can you climb mill while facing off the top?

[Pcmaker]

I was using a 3/4" 2-flute endmill to take off .107 off the top of 3/4" rectangular steel and I noticed vibration on my 1500lb. knee mill when going from right to left. The endmill is taking off the entire top portion, there's no steel left on the side.

 

[Janderso]

That's a big bite. imho.
I could easily do it with a quality 4 flute roughing end mill without any issues.

 

[Jim F]

Should be using a 4 flute on steel.

 

[benmychree]

A 4 flute would run smoother, but I'd use whatever came to hand, but I would not use a rougher for relatively shallow cuts, I'd use one for side cutting, not end cutting.

 

[Nutfarmer]

It's just a good habit not to climb cut on manual machines. We can git away with it sometimes ,but the one time it throws a part across the shop it will be a part with a lot of time already invested.

 

[benmychree]

It's just a good habit not to climb cut on manual machines. We can git away with it sometimes ,but the one time it throws a part across the shop it will be a part with a lot of time already invested.

Yes, but with very light cuts and the gibs or locks set up somewhat, it can be done, but at your peril.

 

[ttabbal]

A 3/4" end mill with a 0.107 DOC. Fairly big cut, some vibration should be expected. I'd use a rougher. Make sure RPM/SFM are good for the material and tool. Keep it cool and lubricated. I use Kool-mist a lot for this sort of cut. Assuming Y is locked, I'm not sure why X moving right or left would be more likely to get vibration though.

As for the title question, no. It's not a climb or a conventional cut. It's probably closest to a slotting cut. Unless I'm missing something. Climb is usually discussed in the context of side forces on the tool. A climb cut would be when the tool rotation can pull the material along. There are a bunch of videos and discussions out there, but Joe Pi's made the most sense to me.

For safety, I've seen lots of pro machinists say it's fine on larger machines that are properly set up and for finish passes only. I do it all the time on my Bridgeport with properly adjusted gibs and backlash and for 0.010" DOC or less. Usually more like 0.005". It's just a finish pass. I could see a deep cut grabbing.

 

[projectnut]

It's just a good habit not to climb cut on manual machines. We can git away with it sometimes ,but the one time it throws a part across the shop it will be a part with a lot of time already invested.

I Have an older Bridgeport with a J2J head, and I climb mill for finish cuts on almost everything. Climb cutting leaves a much better finish. As benmychree mentioned "LIGHT CUTS". In my world a light cut is .020" or less. If you have some play in the leadscrew causing chatter you can compensate by lightly applying the lock. I wouldn't make it an every day practice, but it can be done on occasion without putting undue wear on the machine.

 

[ericc]

A full width cut is neither climb nor conventional. It is kind of a mixture of both. With a face mill, it should be pretty much neutral (pushing with some of the cutter and pulling other parts). If using a fly cutter, there could be half the cut which could be in a climb direction.

It seems that you are trying to take too much. A 3/4" end mill is at the large end for an import 1500 lb mill. I had trouble cutting 4140 PH (or as forged) with large end mills. The import end mills were breaking down due to the heavy usage as well. This was at TechShop, since I wouldn't be using a loose mill at home, neither would I be using those boxed import end mills. I finally was able to complete the cut using a homemade single flute cobalt end mill. It was not pleasant, but it shows that the right tool for the job can help. Try a generic 1/2" carbide end mill, and lock all unused axes; keep everything tight.

 

[Mitch Alsup]

I seldom use more than 1/2" end mill on my 1100 pound knee mill, and I don't take more than about 0.050" in a single cut.