Coromill 390 Sandvik Coromant

[ricky_fire]

Hey guys what do u think about this versatile indexable cutter from Sandvik Coromant (Coromill 390). I think it is cool .

[chris m]

I have used both the endmill- and facemill-style 390 cutters with good success in a variety of materials; the only problems I've had has been rattling the inserts out of the cutter in one application with heavy interruptions. The cutter body doesn't cut particularly well, too negative

[jeff]

I love it!!!

I have the 1-1/2" and 1-1/4" 390 facemills and it has out-performed my Iscar equivalents 2 to 1.

plus when the application suits, it is better to run dry and you can HOG with it all day long.

I love hoggin'.

nuttin like it.

[McRae]

With respect to this cutter, I am curious if everyone else notices that it doesn't like to re-cut chips. Ramping with large diameters (1-1/4) endmill style on a cylindrical shank - sucked right out of the holder and near scrapped the piece. (Poor Glenn near had a heart attack...)

 

After machining a "Weldon" flat, things ran smooth. My favorite cutters of all time are the R200 Buttons - they run like kittens... Purrrrr.

[chris m]

Where'd you get one without a Weldon shank?!?!

That, i agree, would be scary

[jeff]

A "weldon" flat is priority when roughing.

and the r200 buttons are very nice also!

[McRae]

Check the extended length program. There are absolutly no flats on them - there are also no flats on the metric shanks either. The failure I had was in a sidelock holder with only an orientation flat on the tool - not undercut to prevent pull out. -5 degree flats (whistle notches) are even more superior but try to find a manufacturer that makes them as standards...

 

Perhaps the europeans have better physics than here in North America... I also use the Corogrip Chucks to hold the metric shanks and so a flat is not necessary.

[chris m]

I don't use an extended length or a metric shank cutter, so I guess that would explain why my 390s have weldon shanks (happily); I'll have to remember that in the future to avoid loud bangs in the shop.

 

Corogrip chucks are very nice, but also very$$$$$$$$$$$$$$$

[Mgrenier]

Hey Andrew,

 

I asked the question to our Sandvik rep about the flats on the extended shaft and he tells us that it is made like so so that people can cut these tools to the appropriate length for their application without worrying about the position of the flat. It is an easy thing to do for any machine shop.

 

P.S. I love sandvik cutters

[david b]

I use the coro(390)cutters all day every day they are fantastic I use them to do all my vertical pockets and inserts for tool making. We use Dia 16,20 and 25mm two and three inserts,short and long series. I can not speak highly enough of them.

[McRae]

Martin,

 

Check out Louis' March picture on the Sandvik 2002 calendar. I met this guy once at a trade show, what a character - he knows his stuff...

 

Also - Metric cutters are standard coolant thru while inch sizes are hit and miss.

 

[ 07-03-2002, 12:10 PM: Message edited by: MfgEng ]

[bryan.davis]

Been using these cutters for 3 years now, Ive a preference for the 17mm inserts over the 11mm.

 

Someone mentioned they dont like cutting chips, yup, thats a problem, and to get the best you must use a good directed air blast to keep the immediate cutting area clear.

 

When we first bought these our sandvik rep gave us a demo with a 25mm 17mm inserted tool, full width slotting in mild steel 5mm deep, ramp feed in etc on a conventional machine.....

 

feed rate 1150 mm/min

 

SOLD

[ricky_fire]

Heys Guys since we have talked so much about Coromill 390 and the majority of u have liked this cutter how about some feedback on the Feed,Spindle Speed, ap, ae etc which has given great results. It would be highly appreciated.

And where is James Meyette I like that guy

especially that Fish saying of his. I wholeheartedly agree with James.

[david b]

Here are some feeds and speeds i use for the 390

cutters.

I cut tool steel mainly P20,at around 300 brinell.

Cutting speed of 165 mmin, Feed 0.15-0.2tooth

Eg: Dia 16mm coro two inserts(390) =3300 rpm x 1300mmmin x 2mm depth of cut.

Dia 25 3mm depth of cut.

 

I use them to rough out out my pockets and inserts

leaving 0.1mm stock.

Then take a finishing contour pass to final size.

 

The only bad thing about these cutters is they are all undresize.So you have to turn the shank down to stop rubbing.

 

My new Dia 16mm acually cuts at dia 15,87mm

Why don't they make oversize cutters?

[chris m]

Are you sure your 16mm isn't really 5/8"? It sure sounds like it is...

 

If you guys would just get on board with us in the real (inch) world, there would be no problems...

 

C

[chris m]

Derrickg

 

I run an 1-1/2" 4 flute endmill style 390 cutter in 6061-T6 at 2000 SFM (limited by machine horsepower) with a 3/16" axial DOC and 1" radial DOC in a little Matsuura RAII with a .030 IPR feed and the cutter loves it, if only my machine had some more horses...

 

With the Sandvik 3040 grade insert, these cutters run great in iron (350 SFM dry in heat-treated ductile iron) for us us well.

 

if you're going to run one, have the Sandvik guy come in and work your application with you, they are usually pretty knowledgable and if they smoke it, you don't own it!

[jeff]

I use an 1-1/2 dia. with 3040 inserts in mild steel burnout material and run it about 1700 rpm and approx 55 i.p.m. with .200 depth of cut and no coolant.

total slot depth is 3/4 deep and 8" long and i can get about 30-40 parts with the same index.

[Slixmix]

I believe a lot of tool makers are leaving the weldon flats off for balancing purposes. We run insertable scoop cutters in hydraulic chucks at high rpm and if the cutter had a weldon flat, it would throw the balance off big time.

[david b]

Im running metric cutters for sure

quote:

---

---

What are inches?

My 25mm coro cuts at dia 24.9mm

My 20mm coro cuts at dia 19.84mm

 

I run them dry always and with threw spindle air,air is a must!!

 

I have even cut hardend tool steel with my coro's

58 RC.

[Mick]

The 390's ARE undersize. We have two 32mm cutters here, and one measures 31.67mm and the other one is 31.84mm.

Its a reall hassle to have to turn the shanks down, but according to Sandvik Coromant, they are tightening the tolerance on the 390's.

[chris m]

I agree that my metric 390s cut small, that's why I still wonder about them secretly wishing to be inch cutters, I know my 32MM cuts right on 1.250"

 

Slightly off the topic: I have found that Sandvik's quality as of late has been not so hot; has anyone else felt this way?

 

C

 

[ 07-10-2002, 07:36 AM: Message edited by: chris m ]

[McRae]

Remember that the published insert tolerances are in the order of .005" - These inserts are pressed and sintered and even though the dies are adjusted for shrinkage, there is still going to be a normal distribution. An inserted tool will also have to have the locating points of the insert pocket absolutly pristine in order to hold the "size for size" expectation as outlined above. These points will degrade and wear with the use of the tool and over a period of time will become worn essentially making the tool body a consumable item as well. When required to have a tighter tolerance, I always use a finishing tool after using the Indexable for roughing.

 

As sharp and free cutting as the tool may be - it is like trying to shave your beard with an Axe...

[ricky_fire]

Thank u guyz for all the information especially

david b , chris m and jeff .Keep it up Guyz

I definately agree with some of u that the Coromill 390 is risky for finishing,especially for size to size jobs It is better to stick to roughing and semi finishing.About 3 yrs back I had a 16 mm Coromill 390 which was oversize ie 16.05 mm. Now I have three 16 mm cutters with undersize.They have highly fluctuating tolerances

which as somebody said Sandvik is trying to reduce

Hope they do that soon.The Coromill 390 is like bread and butter to me.

[chris m]

Any time

[david b]

GLAD TO HELP

 

My Sandvick rep told me that the cutters are under size,so if u pick up (say) a Dia 16mm coro

and program it for cutting at Dia 16mm.

The job will never be wrong,because the cutter actually cuts undersize so there should always be material to take off.

 

For finishing i program composation to WEAR, wich means i can measure and adjust on the machine.