Indexable insert face mills and shoulder mills
#1
I don't mean for this to be a tool gloat, but educational.

Many of us find ourselves with the need to remove a lot of metal from workpieces. Sometimes it's a wide, flat face that would take many passes with end mills, or long and slow passes with fly cutters. Other times we need to remove a lot of metal from a surface that intersects with a shoulder. Again, end mills are your go-to tool choice for most applications, though sometimes there's just too mugh to remove or it's taking too long. The answer in both instances would be to use indexable carbide insert cutters.

In true face mills, the increased lead angle of a true face mill cutter can significantly reduce the horsepower requirement to make a cut. This allows you to make bigger cuts on low HP machines, or much heftier cuts when you have power to spare. A 90º shoulder mill can often do the same job, though it may need 2x or more power for an equivalent cut done with a 45º face mill.

In selecting the right tools for your shop, there is the first fundemental consideration. Other factors are insert cost, grade selection, chipbreaker (insert top form geometry) choices, tool quality and source, mount type, diameters, and more.

I have found that the most-often used face mill on our 1HP Bridgeport to be my 2-1/2" 4-insert 45º Widia cutter that uses SEKN43 AFTN inserts. It has a fairly high shear angle along with thick inserts that have proven to be quite sturdy and long-lasting. Second behind that cutter would probably be the 1" 2-insert 90º shoulder mill with 16mm tall inserts for deep shoulder cutting.

Most low-budget home shops might do well to start out with a 1" to 1-1/2" (25mm to 40mm) shoulder milling cutter. I say this because you can mill a face using a shoulder mill, but you can't mill to a shoulder with a lead angle face mill. I do NOT recommend the cheap Chinese-made milling cutters from the likes of Shars or other no-name sources, including Tools4Cheap.net. Those vendors are good for some stuff, but indexable milling cutters isn't on my list. Better to buy a current, name-brand product and know you'll be able to get quality name-brand inserts for it.

Here's some photos of my cutters, let the questions begin!

Face milling cutters, 45º lead angle. From left to right a Walter F2280 4" taking 6 ODHT/ODMT00504ZZN inserts, a 4" Widia and 2-1/2" Widia both using SEKN1204AFTN inserts, and an Iscar F45 1-1/2" cutter taking SEEN1203AFN inserts.
[Image: IMG_0988-r.jpg]

Various shoulder mills include Valenite V590, Valenite-Safety V690, Kennametal KD something, a Kyocera that uses TPG 42x inserts and is long gone (not a recommended mill insert geometry), and various others.
[Image: IMG_0740-r.jpg]

I'll follow-up amy questions.
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Thanks given by: Mayhem , EdK
#2
How much of the mill should you engage into the work on any one cut and does it differ from HSS/carbide mills (if so, why)?

As my mill isn't up and running yet, it is questions like these that I will be asking before I let loose on some unsuspecting steel.
Hunting American dentists since 2015.
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#3
Ooow - very nice Ken Thumbsup
Smiley-eatdrink004
DaveH
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#4
That's a great question, Darren.

Generally speaking, it takes X amount of horsepower to remove X volume of metal in X amount of time. There are a great many variables at work, so how much you can actually cut varies widely. A cutting tool is a cutting tool, and the only difference between HSS and carbide these days is the speed you use in a given material. Other factors affecting milling cuts are:

Width of cut vs. cutter width
Shear angle of the cutter edge
Lead angle of the cutter edge
Sharpness of the cutter edge
Top form geometry of an insert or hook in the HSS cutter's edge

The key to getting the highest material removal rate is chip-thinning. Those 4" and 2-1/2" cutters with the 45º lead angle and about 15º shear angle reduce force so much that I'm able to get a surprising width or depth of cut with only 1HP at hand. A straight-flute shoulder mill of the same same would stall the motor instantly.

I goota get going, I'll post more later if you guys want more info and perhaps videos.
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#5
Earlier this year Ken helped me acquire a new face mii, made by Walter. It replaced the unit in the first picture, the difference in usage is night and day, not unlike the difference in appearance. The Walter is very smooth cutting and leaves a great finish.

1 - the old cutter
2 - the Walter F4041
3 - the Walter F4041
4 - the new arbor
5 - the insert
6 - loaded up
7 - loaded up

Again thanks, Ken


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jack
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#6
(11-05-2012, 07:36 AM)PixMan Wrote: ...I'll post more later if you guys want more info and perhaps videos.

Thanks Ken - I'm sure you already know the answer to that question!
Hunting American dentists since 2015.
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#7
(11-04-2012, 10:48 PM)PixMan Wrote: Most low-budget home shops might do well to start out with a 1" to 1-1/2" (25mm to 40mm) shoulder milling cutter.

Ken, what is a typical (ball-park) figure for an item like this including inserts?
Same question for a similar (2", 2-1/2") 45° lead cutter?

Chin
Willie
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#8
(11-05-2012, 07:52 AM)the penguin Wrote: Earlier this year Ken helped me acquire a new face mii, made by Walter. It replaced the unit in the first picture, the difference in usage is night and day, not unlike the difference in appearance. The Walter is very smooth cutting and leaves a great finish.

1 - the old cutter
2 - the Walter F4041
3 - the Walter F4041
4 - the new arbor
5 - the insert
6 - loaded up
7 - loaded up

Again thanks, Ken

Jack,

I bought one of those from Ken also. I haven't used it yet because it's such a beautiful tool that a worthy project hasn't come up yet to do it justice. It will though, real soon. I'm curious has to how it cuts nasty 1018 which is what I have most of.

Ed
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#9
Willie (Highpower),
Those 2" Walter F4041 cutters are very expensive at list price, somewhere around $440! However, I got an unbelievable price for what was supposed to be 4 of them on eBay. When they arrived I found that the seller had shipped only 3 of them, one was obviously used. I complained and he sent me a 4th cutter but it was an F4042.UB.051.Z04.12, a 2" 4-insert cutter that takes ADMT/ADGT1204xx 2-edged inserts rather than those LNGX130708R-L55 inserts shown in Jack's photos. Keep an eye on eBay as I did and you just might score a deal.

I sold them for very nearly what I paid, so Ed, Jack and a couple other guys got a GREAT deal.

Ed,
I believe you bought inserts from eBay, the LNGX130708R-L55 grade WSP45. That WSP45 is Walter's best all-around grade because it works on steels, stainless steels, and superalloys (such as Inconel.) If that is the grade you have, then the recommended cutting speed in 1018 is 750sfm if cutting 1" to 2" width of cut, and up to 950sfm if 20% of the cutter diameter or less. Of course you can use lower speeds to preserve tool life even more, but if you drop much below 350 to 400 surface feet per minute you might risk chipping the inserts. Yes, those a FAST cutting speeds in 1018, but it'll do it. I strongly suggest you set up chip guards so you don't throw hot chips around too far. Chip load is given in "inches per tooth" to be .006" to .010" ipt. Use lower rates at full cutting width, and increasingly higher at less width of cut. ALWAYS climb mill if your machine has no backlash in the feed screws. Chip-thinning is a result of climb milling, and you get thinner chips as the width of cut decreases so you can feed even faster.

If you are milling only carbon steels and want the fastest running, longest-lasting inserts then look for a set of grade WKP35S or harder WKP25S. Those can be used on steels and cast irons and give great results. In steels, bump up the cutting speed by 15% over the WSP45 rates when using WKP35S, and 25% higher the WSP45 when using WKP25S. Those speeds are so fast that you might run out of torque, as you'd be spinning the cutter at 1900 to 2250 rpm!

For aluminum and light cutting on austenitic stainless steels, there's a coated grade WXN15 which is what Wrustle uses on his. Those and the uncoated grade WK1 (for aluminum only) are extra-sharp. The coated WXN15 does last longer. I think Wrustle had used his nearly every day for 3 months (or more?) before indexing the inserts. No speed limits on typical 6061 aluminum, but do be more careful with 7075. Big Grin
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Thanks given by: Mayhem , EdK
#10
Great information Ken. Thanks for educating us all on insert tooling. Thumbsup

Ed
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