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Horsepower

You know sometimes you just have to look at something in your real world work envelope before the truth hits you in the noggin. Since I am getting very close to actually using the Hurco retrofit mill I thought I ought to pick up a fair face mill to go with it. I found a 1" Kwik 200 shell mill holder on Fleabay and pulled the trigger. Then I started looking of a shell/face mill to go with it. I had fantasies about flying though 6" aluminum plate facing in a single pass, but I started plugging numbers into ME Consultant. They looked awesome. The mill will go that fast. I have been testing with decent results at 250ipm (no load) and I have no fear about being able to do some serious cutting at 100-150IPM. The speeds and feeds with big stuff were coming out right in that range at spindle speeds the mill will turn 2500 +/-. I was getting all excited about being able to make chips fly.

Then I happened to notice the horsepower requirements calculated.

I decided a 3" 5 insert shell mill would do. LOL.

Reply to
Bob La Londe
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I prefer insert shell mills with an even-number of pockets; allows me to remove teeth if I want to lessen the load...for instance with six, you can run an insert in one, two, three or six stations.

Every mill has sweet spot in it's HP/Torque curve....good to look it up if you don't already have a copy of it in the manufacturer specs.

For highest stock removal rates, run at that rpm and then select a tool diameter to provide the correct SFM for the work material being cut.

Then, either increase depth of cut or add more inserts untill the motor is drawing max spindle load current.

Reply to
PrecisionmachinisT

We hate it when that happens dont we?

But..you can scream right along with that 3" mill. Or go to a 6" mill and simply go slower.

Gunner

The methodology of the left has always been:

  1. Lie
  2. Repeat the lie as many times as possible
  3. Have as many people repeat the lie as often as possible
  4. Eventually, the uninformed believe the lie
  5. The lie will then be made into some form oflaw
  6. Then everyone must conform to the lie
Reply to
Gunner

That is a good idea. Maybe someday I'll be able to take advantage of that, but for now I have the five insert one coming.

I'll go through the manual and see if there is a torque curve, but I don't recall one.

My head hurts. Yer makin' me think. Seriously, though. That's a good train of thought to pick up. Thank you.

Reply to
Bob La Londe

Yep. I plugged in some typical face cuts and got feeds in the 89-130 ipm range with that cutter that will stay within the recommended horsepower for the spindle.

Reply to
Bob La Londe

Well my point was, you can run a single insert if conditions warrant.

Kennametal has REALLY good literature, dunno what's still available but I'll try to remember and check tomorrow.

Reply to
PrecisionmachinisT

Ayup. 89-130 IPM is way fast when you are spinning a 6" milling head. It can be scary fast and make damned sure your work piece is Secure! in the vise before hitting Cycle Start. Do NOT try to use a high hold with a 6" cutter. If you are not holding a bunch of material..use a small cutter to take the load off the work..else those "teeth" can grab the work piece, pull it out of the vise and sling it across the room at astonishingly high speeds and tremendous energy.

Every hobby guy Ive ever known has a hole in the wall somewhere in the shop from work that got out of the vise.......including me. Blush! In fact..Ive got 3 holes in the walls. Blush!!!!

And make damned sure your offsets are correct. Hitting the vise and listening to all those inserts pinging off the walls can really put a crimp in your wallet.

Gunner

The methodology of the left has always been:

  1. Lie
  2. Repeat the lie as many times as possible
  3. Have as many people repeat the lie as often as possible
  4. Eventually, the uninformed believe the lie
  5. The lie will then be made into some form oflaw
  6. Then everyone must conform to the lie
Reply to
Gunner

I could not find much on the kennametal site but the book I'm talking about is catalog 8040 "milling" circa 1998

The technical section comprises the last 160 pages of the catalog and it's absolutely the best reference I've come across in the 35 or so years that I've been in the trade--highly recommended...

Reply to
PrecisionmachinisT

catalog 8040 "milling" - I'll keep an eye out.

Reply to
Bob La Londe

catalog 8040 "milling" circa 1998

absolutely the best reference I've come across in the 35 or so years that I've been in the trade--highly recommended...

Kennametal's online calculators are quite good. The ones I've tried generally agree with other sources. I do wish they had more supporting info.

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Reply to
Ned Simmons

Gunner on Wed, 20 Mar 2013 03:17:49 -0700 typed in rec.crafts.metalworking the following:

At Renton Tech, in the alcove with the surface grinders, there is a ding, high up on the wall, put there by a handle which had been left in place after inserting and tightening the collet into the Bridgeport. Yeah, the ding is pretty close to the height of the top of a Bridgeport, pretty much. Nope, happened before my time.

As they say, the difference between the apprentice and the master is that when something goes wrong - the apprentice says "I thought that would work" while the master says "I forgot that doesn't work."

And watch you don't start in reverse. You can get quite a finish in aluminum that way. Not much cut, but ...

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Reply to
pyotr filipivich

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