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rolland
02-08-2010, 11:24 PM
I purchased one of indexable end mills from Enco, I need to do some facing on a piece of 4140 for a project. I have never used one like this as I have always used standard end mills or a fly cutter so........... I got to thinking :D (a dangerous habit I have) it might come in handy. I ordered the correct inserts for alloy steel but having never used one I hoped to solicit some tips on its use. It is the 1 1/4 diameter http://www.use-enco.com/CGI/INSRIT?PMAKA=422-3012
Any help would be apprecated.

KiddZimaHater
02-09-2010, 12:21 AM
If you have a large, rigid mill it should be a breeze.
You might have problems with a small mill.
Lock your spindle in the raised position, and raise the knee to meet the work.
NEVER MILL WITH THE QUILL EXTENDED.
1000 RPM. Feed it by hand.
If power feeding about .010 - .015 per rev.

Black_Moons
02-09-2010, 01:56 AM
Well, that looks somewhat similar to my carbide insert holder, though yours looks to have more rake.. (mine is negative rake! very lame but great for the extra cutting edges and roughing), One thing i'll say if its anything like mine, you basicly can NOT sidemill with it. something like 0.03" depth of cut before it starts sounding like a jack hammer insted of an endmill. Width of cut can easily be 3/4 the width of the endmill, or even the entire thing (though you might get a worse finish with a full width pass)

with enough 0.03 depth passes, the sides may however achive a good finish if you locked the unused axis of your mill.

On mine, I managed to run it up to the full 1600rpm of my mill against mild steel (1" diamiter for my endmill), though that was a little bit excessive, finish degraded past 900 rpm and the scalding hot chips flying around my shop where hard to dodge and melted into plastic objects. at 900 rpm finish was better and the chips where a little easyer to dodge.. and peel outta my plastic tool containers :P
(Again, mine is negative rake so it can REALLY handle the SFM/RPM, but some modren carbide inserts are CRAZY) yours appears to be posative rake by a few degrees (no insert geometry to assist) so you might wanna stay a little lower on the SFM scale, like 900rpm to start with and see how the inserts/finish fare.. and your mill. (900rpm * 1.25" * PI / 12" = 294SFM, About HSS speed * 3 for mild steel, and *2 for aluminium.. you could go much faster in aluminum, maybe a touch slower in harder steels like tool steels (4140 I believe counts as harder tool steel?) depending on insert quality and type..

DaHui
02-09-2010, 02:33 AM
No problem, just try it on some scrap first. I have face mills in 2", 3" and 4" that I use on my bridgeport all the time. Just don't expect to move a lot of material in one pass...especially if the inserts don't have a positive chip breaking geometry. Okay, the 4" I have is pretty excessive but it was a steal on ebay.

I run the 2" mill (4 insert) anywhere from 800-1200 RPM on aluminum or steel. In terms of feed, just push it till the chips are the right color (on steel) or measure them till you get about .003 chip thickness. Most of the time I just go by the sound.

beanbag
02-09-2010, 03:07 AM
Sorry to say, I think you got the wrong tool. You should either get one that takes APKT inserts and leans them back (for some effective helix angle) if you want to do any side milling, or one of the 45 degree face mills that takes the square inserts (if you want to do facing only). Glacern sells both types, as an example. Return your tool if you can.

TGTool
02-09-2010, 11:07 AM
Sorry to say, I think you got the wrong tool. You should either get one that takes APKT inserts and leans them back (for some effective helix angle) if you want to do any side milling, or one of the 45 degree face mills that takes the square inserts (if you want to do facing only). Glacern sells both types, as an example. Return your tool if you can.

Ha ha. Not only that, look carefully at the picture on the Enco link. It's left hand rotation!!

Actually I presume they just flipped a digital photo L/R to fit their catalog but it does give one pause.

JTToner
02-09-2010, 12:16 PM
I have a similar face mill I've been using in my knee mill with, I believe, TT32x inserts. Face or side milling, I've had good results in 6061, 4140, and A2. Caution, have shields in place , those blue chips come off fast, furious, and HOT. And, at high rpm will sling them all over the shop. For shields I just use Lexan panels on those cheapo HF or Enco magnetic holders for dial indicators. Not terribly elegant, but functional. Oh, forget Chinese inserts. Get name brand European or US made inserts.

rolland
02-09-2010, 01:54 PM
Thanks for the input, guess I will need an flame proof suit for the chips. I have a piece of 4140 that needs squared up to start a project its 2 1/2 square by 3 inches long so my smaller end mills take forever. I will give this a try and adjust from there.

Carld
02-09-2010, 02:50 PM
Why don't you use a flycutter? You can run the flycutter at about 1000 rpm and probably take .050" DOC and make a cut the full width with no trouble at all and the flycutters are cheaper.

PaulT
02-09-2010, 09:06 PM
Sorry to say, I think you got the wrong tool. You should either get one that takes APKT inserts and leans them back (for some effective helix angle) if you want to do any side milling, or one of the 45 degree face mills that takes the square inserts (if you want to do facing only). Glacern sells both types, as an example. Return your tool if you can.

Beanbag is giving good advice here. Mills using the APKT type inserts cut much better on BP sized machines than the old TPG inserts. The geometry of the insert just works better, its a much more modern design.

They work really well on both steel and aluminum with the right inserts, you can get some ground and polished APKT inserts for aluminum that give really good surface finishes. I'd send the TPG mill back, even if you have to eat the shipping costs.

Enco really should stop promoting TPG tooling to home shop users, pro's have moved away from it a long time ago, the newer design inserts just work better, both on small and big machines.

Paul T.

rolland
02-12-2010, 02:50 PM
I thought I would do a follow up since I got a lot of advise on using the indexable end mill.
I needed to square up a piece of 4140 for a project. Well the end mill worked wonderful I got a glass smooth finish with very little tool marks. I ran the tool at 1200 rpm conventional milling with a medium spray of coolant, the chips came off at a light brown. I only needed to take a couple of .025 cuts to square up the piece.
I am a happy miller:)

PixMan
02-12-2010, 03:26 PM
While insert mills that take APKT-style inserts are indeed capable of more abuse (and productivity) than TPG inserts, you can see from the OP's response that it works fine on a Bridgeport when care is taken.

I've got both, and both get used. The APKT-style one is a Valenite V590 B 10 075 WC 15. The AP10-size inserts can take quite a bit of abuse in any material I throw at it, but I especially reach for that one for stainless steels or for big material removal on carbon steels. It's a 3-insert cutter that can ramp into pockets pretty good too, though I don't do that often. I do know the cutter can take off more metal than the Bridgeport's motor can, any day.

For lighter cuts at slow feed rates, I have a no-name 3-insert 1-1/2" cutter like the Enco one (right hand though!) for which I have sharp uncoated inserts. It's great for aluminum & brass.

beanbag
02-12-2010, 05:05 PM
Well, as John said about Evan's indexable cutter:

"it can't not work well, it's a rotating tool" :D

Mcruff
02-12-2010, 06:02 PM
Beanbag is giving good advice here. Mills using the APKT type inserts cut much better on BP sized machines than the old TPG inserts. The geometry of the insert just works better, its a much more modern design.

They work really well on both steel and aluminum with the right inserts, you can get some ground and polished APKT inserts for aluminum that give really good surface finishes. I'd send the TPG mill back, even if you have to eat the shipping costs.

Enco really should stop promoting TPG tooling to home shop users, pro's have moved away from it a long time ago, the newer design inserts just work better, both on small and big machines.

Paul T.
TPG inserts are about 1/3 the price or less of the APKT style inserts so for hobbiest they are a much better deal. We use them at work, at home I use TPG's due to cost.

PixMan
02-13-2010, 12:08 AM
TPG inserts are about 1/3 the price or less of the APKT style inserts so for hobbiest they are a much better deal. We use them at work, at home I use TPG's due to cost.

The true cost of expendable tooling lies not in the initial outlay of cash, but in the cost per part. While true a TPG insert isn't as expensive per edge as most APKT form inserts, their productivity pales in comparison. How many edges and how much time is spent with one vs. the other? At home we have the luxury of time (but not always) so we often overlook true cost per edge.

PaulT
02-13-2010, 06:54 PM
I agree 100% with PixMan on this issue. I get much better performance, tool life and quality of cut with APKT based endmills than I did with my original TPG based ones, so although the APKT inserts cost a little more they are cheaper in the long run. You can also get them pretty cheap from www.latheinserts.com and www.carbidedepot.com .

I find the same thing is true on lathe inserts. While CCMT inserts cost more and only have 2 cutting edges, their performance and lifetime is so much better that I put all my old TPG lathe tooling away.

Paul T.

Mcruff
02-13-2010, 11:06 PM
At work everytime we change out our APTK cutter it cost $200, hobbiest would have a hard time outfitting that the 1st time let alone changing it. When you can buy TPG inserts for $2 an insert its at least useable and you can spread that cost out over a long while even if it doesn't last as long. If you crash it you lost $6 in inserts the other one you usally lose at least $40 and could be as high as $80 (hobbiest not pro), alot of money for a hobbiest. I use this stuff for a living so I know what you mean but guys using it at home generally don't have the budget for that kind of tooling.


If you don't mind radii get rid of the APTK inserts and go for the round ones such as RCMT, they will give tons of edges and will cut about 10x the cubic inches of material that the other ones do and at a much much lower cost.

PixMan
02-14-2010, 07:19 AM
Well of course it makes no sense for a hobbiest to be replacing a mill body for $200.

And it's not economical for a shop owner either. While accidents happen, why is it more acceptable if it's a "shop tool" at work? I've never understood that thinking. I treat every tool as though it were my own (and nowadays, most of them are.)

I got my Valenite V590 cutter brand new in a kit with 10 inserts for $65 on Ebay. I look for deals like that and now have tools for dad's home shop that are as good as anything "they use at work." I figured if it's good enough to make money with, it's good enough for me.

There are incredible deals on Ebay for quality name-brand tools at really cheap prices, especially turning inserts. Since I educated myself about them and know what I'm looking at, it's been amazing how cheap I can get the tools I need for the home shop. Why blow $10 on a scratch-off ticket if I can get 10 good CNMG432 turning inserts? I have a lifetime supply for about $30, and grades for all materials. The shop owner usually doesn't have time to go hunting Ebay like I do though. The only thing to watch out for is getting into an obsolete milling cutter that you won't be able to get inserts for.

Boucher
02-14-2010, 09:34 AM
The fly cutter is a good tool and definately has its place in the home shop environment. If one is transitioning to indexable insert milling cutters take a step upward and go to the state of the art not something three generations of cutters back. Try some of the Glacern products they all work good and are fairly priced. They support this site with their advertising and I appreciate that.

Mcruff
02-14-2010, 10:53 AM
Well of course it makes no sense for a hobbiest to be replacing a mill body for $200.

And it's not economical for a shop owner either. While accidents happen, why is it more acceptable if it's a "shop tool" at work? I've never understood that thinking. I treat every tool as though it were my own (and nowadays, most of them are.)

.
I didn't say mill body I said inserts. Our inserts for our tool at work cost $20 an insert, 10 on the tool, our company wouldn't use ebay even if they could, the place is to large and they haven't got time to search ebay for a deal. When a CNC is running and 1 insert breaks for one reason or another you have about 3-5 seconds before a total melt down occurs, catch it in time its only inserts go more than about 10 secnds and the tool is garbage. We have lost several $300-$500 tools in the last 6 years for one reason or another, never an operator error. Last week I cut 900lbs of steel chips from some large parts we were making in 2 days (24 hours). I can't afford the luxury of time when I have to do it, I can afford to push the tools like they should be and if a tool goes down and is tore up I have a replacement, its cheaper than the job being late.. The boss and the company expect it. As far as taking care of tools, I take better care of the tools than 99% of the people out there. I have been in this business for 30 years now, 7 1/2 of it I owned my own shop and built high end plastic injection molds. I am quite capable of taking good care of whatever I am using but crap happens. Hell my drill index is 30 years old and I have only replaced maybe 15 drills in it, they have drilled 10's of thousands of holes in that time.
As I stated earlier cost is a big issue for home guys, my TPG's at home last a long time cause I don't push them hard on a bridgeport. My lathe inserts I bought are tpmg's bought about 5 years ago, I have used 2 inserts out of the 20 I bought, the machine is used constantly. If you can find more modern insertable endmills for a good price and inserts to match go for, but don't condemn these guys for using older proven styles because of cost and inexperience issues. The TPG units are so common and cheap its pitiful and that has a lot to do with why they sell so many, there trusted, proven and reasonably cost effective.

lazlo
02-14-2010, 12:49 PM
I agree 100% with PixMan on this issue. I get much better performance, tool life and quality of cut with APKT based endmills than I did with my original TPG based ones, so although the APKT inserts cost a little more they are cheaper in the long run.

I'd like to point out that you guys are comparing two extremes: TPG's are old-school inserts with no surface features (no chipbreaker to optimize the rake angles). To make matters worse, the cheaper TPG facemills have the inserts laying flat in the pocket (no radial rake) so they slap the workpiece and hammer the spindle. But they've been around for 30 years, so you can literally buy name-brand TPG's for 25 - 50 cents each.

The APKT's, by contrast, were until recently the latest and greatest inserts: they have a helical twist molded into the insert, and with a good mill body, they're just about optimal for surface finish on low power, low rigidity machines. But the inserts are $7 - $11 each at CarbideDepot, and $15 - $20 each retail (!)

I love my APKT facemill, but I get nervous when I load it up with 6 inserts @ $7 each...

But a good compromise that a HSM'er might consider is an SEHW "shear mill". It's a square insert turned on it's edge (45 lead angle) with a modern chipbreaker shape in a facemill pocket with steep axial and radial rake that gives the insert a high positive cutting rake angle -- very low horsepower and rigidity requirements. You can find Kennametal KSSR facemills which use these inserts for dirt cheap on Ebay ($50 - $90), Bison and Dolfa (same company?) sell them inexpensively at Penn Tool, and the inserts themselves sell for $2 - $4 depending on the grade and coating.

The inserts on the top row are SEHW's. The top-right is has an extreme positive rake and is razor sharp, for finishing aluminum. The bottom middle is a Sandvik's RA-245 -- their proprietary version of the SEHW inserts with a more sophisticated chipbreaker and a carbide anvil for crash protection:

http://i164.photobucket.com/albums/u15/rtgeorge_album/SEHInserts023s.gif

PixMan
02-15-2010, 07:11 AM
I have a 2.5" 45 high-shear mill also, I think it's a Widia. What a huge difference in the loads on dad's 1HP Bridgeport. Can a machine like that use all of what the cutter can do? Not a chance, but as lazlo mentioned, it is SO much easier on the spindle bearings. Cuts really smooth.

Mcruff, I am not disagreeing with you one bit, and in no way am I suggesting that you have a problem with trashing milling bodies. If you owned or supervised a shop you know I'm just bemoaning the lower-skilled people who don't respect what tooling really costs. Those are the guys who don't have a home shop!

I do see the value of using TPG inserts for some tasks in the home shop because of the price, but they're not a very rugged geometry. You have been around long enough that you know how to use them on both lathe and mill applications successfully. Many a novice would try to use them too aggressively as their first inserted carbide tool, trash the inserts and the cutter and form an opinion that carbide tooling just isn't worth the money.

Making the situation worse for TPG inserts is the issue of milling grades vs. turning grades. While you can't use an APKT or SEHN insert on a lathe, TPG's have holders for both types of machine. For some applications, such as a C-2 uncoated grade used for turning cast iron, no problem. Try milling with a C-6 carbide with too much feed and you soon have two-piece inserts.

For me, I've shopped carefully (and been given a few good gifts) for the home shop and feel dad & I have the optimum tools for the way we work. He's more inclined to use a reground HSS end mill before the inserted carbide, I'm the opposite. ;)