Author Topic: Shell milling cutter?  (Read 484 times)

100LL

Shell milling cutter?
« on: January 18, 2019, 08:44:54 AM »
I believe this type of mill is shell cutter?  Not sure about that.  Iíve seen new things called the same name that have insert tooling but I thought those were called face mills.

Anyway, Iíve got a bunch of these along with the necessary arbors (well, maybe I donít have all the right sizes but Iíve got at lest one arbor to fit most of the cutters)

My problem (and question) is when do you use these?  I tried cutting with one yesterday and got some god awful chatter and she just didnít want to cut the mild steel I had vised up.

Now, Iím a newb so I could have the wrong, well, anything.  Maybe itís too dull, maybe my speeds were wrong, depth of cut, whatever.  I swapped it out for an end mill and went about my business....and am now seeking advice from the experienced.

Carpenter84

Re: Shell milling cutter?
« Reply #1 on: January 18, 2019, 09:05:03 AM »
Looks like a shell mill to me. But a cutter that big is gonna need a pretty stout machine...
What was your spindle speed and feed? Doc?
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Shell milling cutter?
« Reply #2 on: January 18, 2019, 09:55:49 AM »
Yeah, they are meant to run at SLOW RPM's and feed as fast as you can.  Generally see them used on heavy duty mills like K & T's.

It could be they are not sharpen correctly.  Maybe too much back rake? 
Ken

Uglydog

Re: Shell milling cutter?
« Reply #3 on: January 23, 2019, 05:11:09 PM »
Yes, what they said!!

In the background it looks like you might have the swivel base under the vise.
If you are making cuts which require a swivel base then defiantly use it.
However, there may be enough flex with the big cutter that it is introducing chatter.
Consider removing the swivel when ever it's not needed.

Daryl
MN

100LL

Re: Shell milling cutter?
« Reply #4 on: January 23, 2019, 06:10:08 PM »
Great advice on the swivel base.  Hadnít thought of that, plus it will help with vertical clearance.

A related topic, perhaps deserving a new thread...but absent a surface grinder, how does one get the best surface finish on a steel part?  Largest 4 flute end mill you can fit, 2 flute, face mill,...?

4GSR

Re: Shell milling cutter?
« Reply #5 on: January 23, 2019, 08:09:24 PM »
Either a face mill or fly cutter.  Used a fly cutter for years before I got my first face mill.
Ken

Carpenter84

Re: Shell milling cutter?
« Reply #6 on: January 23, 2019, 10:00:40 PM »
I have a decent facemill on a cheap arbor, if I had to choose, Iíd go back to a fly cutter. Got a better finish. Albeit, slower. (Or, I could just get a better arbor...)
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Shell milling cutter?
« Reply #7 on: January 23, 2019, 10:34:35 PM »
Face mills are really made for rigid machines.  Bridgeport type mills are marginal on face mills but work.  In my earlier years, we built special machines that used a 8" OD face mill that used SNu633 inserts on a 45 degree lead angle.  I would bury the cutting edge into a 6-3/4" OD bar about 7/16 deep and mill a helix down a 30 foot long bar of 4145HT.  That size bar took 6 passes to create the helix required.  We would feed at about 60-70" minute at 300 RPM. Didn't take long to make a pile of chips 4" deep on the floor.  This was before we installed the conveyor to collect the chips and put into dumpster.  Didn't take long to fill the dumpster, too!

Carpenter84

Re: Shell milling cutter?
« Reply #8 on: January 24, 2019, 06:04:26 AM »
Yes, I am very aware my 2Ē 3 flute facemill can easily and happily sus out the wear in my mill and place it directly into my surface finish. Lol. But, itís quick. so, ya...
I need to build another fly cutter that wonít break.  ;D
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Shell milling cutter?
« Reply #9 on: January 24, 2019, 09:05:37 AM »
Yeah, I'm not saying not use them.  Just saying they are hard on the smaller machines.  I use them too, and they are noisy, but they leave nice finishes. 
Ken