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Carbide roughing mill coming out of collet ER 40

Xjenderfloip

Stainless
Joined
Feb 9, 2005
Location
Rotterdam
Im trying to reach some serious values for milling on a cnc lathe with c-axis.
Example, i was milling a big trapeze thread.
First straight, then the flanks.
Im european so ill try to convert the values i use into inches.
I used an iscar roughing mill .4724 (12mm) in C45 (mild steel) im allowed around 3000 rpm with 1000mm feedrate per min (is that 371 SFM ?)
Dept of cut only .196 (5mm)
Anyway when i doubled the dept to .393 , the mill got pulled out soon after till it was cutting .70 deep before it got silent :eek:
The problem is that the driven tools we have are all ER 40 collets , i have looked for ER 40 collets like a weldon clamping, but cant find any supliers.
I could make them myself but only if no other option since the time it takes doesnt justify the price of collets.
But if i have to , does anyone know the exact corner the cone of a ER 40 has to be , is it degrees or is it relative like 1:3 ?
I can measure a collets' degrees but well its got cuts and i want to be exactly if i have to make them.

Also anyone out there doing heavy cuts with collets?
 
I use ER 40 and TG 100 in my mill. The ER's are great because each collet handles a wider diameter range (1mm) than the TG 100's, but the downside is that they sacrifice grip force to achieve a wider grip size range. If I have any heavy milling to do I try to use a TG 100 or an end mill holder. The end mill holders provide the best grip but generally you get a longer extension from the spindle nose than when you use a collet. This can lead to cutter vibrations. So for me, the TG 100's provide the best compromise of grip force and reduced overhang. I hope you find a solution that works for you.
 
generally, collets are ok for light setups....
but ....you're hogging! of course it's pulling
out

like metro said...get yourself some proper endmill
holders...i use toolmex(bison) for most jobs,
and have some pricey sandvik holders i use for
special occasions. both are european(swiss+polish)
manufacture, so i would think they would be available
to you .......
 
Hey i like hogging, but i think its not real hogging yet what i did.
I have a bigger rougher that could handle 2700mm feed (1000 SFM? ) :D
You see the problem is that its livetooling on a cnc turning center, im dependend on what companies make for BMT 75 clamping on the turret.

I just found some blanks for ER 40 from eppinger , so i could make a precise hole and side bolt the mill and grind a flat on the carbide mill, altough its not recomended, i dont see any easier way to hog.

Unless there are supliers that have heavy standard live tooling holders that support a mill chuck or anything strong, i think it will be an expensive adventure to let them custom make.

We also use sandvik for alot, what holder do you have from them?
 
Xjenderfloip
I’ve done a fair bit of C axis milling on my lathe using Eppinger live tooling…radial and axial holders, their very robust. The limiting factor (besides 3000 rpm) as you have found is the ER 40 collet. A collet blank with a setscrew in the side combined with a Weldon flat on the cutter may just work. I think your depth of cut being twice the cutters diameter and in steel no less overwhelms the collets holding power. If the cutter and machine were purrrrring along before the cutter went silent then a “solid collet” is a great idea!! Keep us informed!!
Carl
 
ER collets have a range-of-collapse of about .040" (1.0 mm). Their greatest grip strength (because of greatest contact area) occurs only when the tool OD just slides into the collet ID. Then the collet is not forced to expand, and barely has to compress to hold the tool. One ER collet will best hold a tool with an OD about .001" (.0254 mm) smaller that the collet ID.

Intermediate sleeves have been used for some time as a way to address this problem:

http://www.schunk-usa.com/schunk_files/attachments/zubehoer_Zwischenbuechsen_SINO-T_DE_EN_FR.pdf

The Schunk Sino-T system can be used if the toolholder body will fit your machine's spindle:

http://www.manufacturingtalk.com/news/shu/shu102.html
 
As Precisionworks said, use a collet with the same nominal ID as the shank.

I've also noticed an improvement in holding power if the collet is washed in solvent (or use a solvent soaked Qtip), and the tool shank is also washed in solvent. That thin oily layer makes a difference in the grip.

It might also help to add a dab of Loctite to the shank. This is a desperate measure perhaps, but I've used it to some benefit in solid holders, as it keeps the tool shank from fretting in the holder. I'm not sure how much good it would do in a collet. I do have to use a press to remove the tool afterwards, but its in there once the loctite has hardened up :D . A little heat will speed the cure rate.
 
Someone correct me if I'm wrong here.

Endmill holders are best but most carbide endmills do not have a flat on them. It is my understanding that er collets have better gripping power than other styles, not sacrificed, as stated earlier. The added bonus of have greater range per collet needs to be used wisely. You can hog with carbide hog mills as long as the collet is exactly the same size as the end mill. Second best would be if the end mill is slightly bigger than the collet, and the big no no would be if the collet is made for a larger size than the end mill.

BTW, I use er collets all the time for hogging, and never have end mills pull out.
 
Dave, can you guaranty me that with a new, cleaned collet the same size as the new sharp carbide mill at max surface speed and feed at 2X D dept will hold for 1 hour cutting without coming out?
I dont think so, becuase thats exactly what im using.
If a drill/mill/tap slipped in a collet and leaves a trail i trow it away and get a new one for 10 bucks.
Its not that they always come out, its that i cant risk it at some products, and you'll see that the mills tend to come out right at those kind of things.

Btw can you give me an example of what you call hogging, speed feed and dept?
 
if a collet is what you have to work with then you should try to change the process to better accomodate your tooling situation. since this is a live tooling situation on a turning center i would lighten up on the depth of cut, ex: instead of two deep cuts do 4 light cuts and max out the spindle rpm and feedrate for that style endmill/ material combination. you should be able to almost double your feedrate with the lighter cuts so your cycle time should not be affected much. if your cycle time is still not acceptable then look at other parts of the process where your tooling is better suited and optimize their to reduce the cycle time. i am not fond of endmills in collets especially in steel applications. they do like to pull out it is the nature of the design. just my .02, good luck
 
The ER40 system is not a bad way to hold solid carbide EM's - It is the system I use, and have a full set from 3mm to 26mm.

That said, it is not the system that provides maximum grip. The TG collets do that, providing about 300% more grip force (as measured by pullout). The TG's have a smaller range per collet, which is one reason for their tremendous grip.

The "ultimate" collet would be TG1000, where 1,000 collets would be needed to cover the range from .001" to 1.000". Surprisingly, no one (yet) makes this system.
 
With TG collets you can get those with the pin for holding end mills weldon style. Much more robust setup. Also, TG's have a much longer engagement area available.
 
If you can get ER40 blanks then machine them with a several thou/inch (or metric =) shrink fit. Heat them up, slip them on (quickly...) and hog to your hearts content! They will probably now be "consumables" if shrunk on tight enough.
Cheers, Stan.
 
Xjenderfloip,

No, I guess I couldn't garantee it. When I do any hogging, if it's 2X the depth, then its usually about 1/2 the cutter radially. Sounds like this might be a candidate for those hydraulic holders I've seen. Never really checked into them other than they are pricey. Maybe about $350.00 for the holder, and then I think you still have to buy a collet for it. But they are definatly made for hogging like your talking. As pricey as that is, it's still cheaper than a entire shrink fit system.
 
Crunch, i saw those shrink adapters and i tough the same as you, looking not very rigid, but iscar makes very good holders and i doubt they havent tested them with their own roughers, nonetheless, ill pass on that.

Dave, yea so i wasnt even there yet (2xd).
The livetooling has 10 Hp and im not fully satisfied till i use that :D
Ive got jobs coming that require shiploads of metal removal.
I worked with a hydraulic chuck, and even they can be pulled out, altough it didnt happen to me, one of my collegues was in tears when his 2" miller came out on a customers'gearing axle wich only needed a slot.

Good news after a few hours search i found out a few things trough catalogs.

First, Iscar has standard carbide roughers with a weldon flat, i havent seen them before so i will order some now.

Second, Eppinger sells weldon holders that go in a ER40 holder afterall, they are clamped with 4 bolts to the flange (of a Eppinger livetooling) and the ER40 shaft will function as a centering mandrel for acuracy, they come in metric and inch standard types, called:
"preci-flex adapter weldon standard" (duh).
heres the link
I overlooked them in the catalog because they dont mention the shaft type as ER40 but just refer to the largest dia of the ER40 shaft as "40".

Question, i also saw they have "preci-flex adapters whistle notch standard" , anyone knows what whistle notch is?

Third, i saw Iscar has new carbide endmills that have 4 flutes of wich 2 are roughing flutes and 2 finish flutes, they allow for the same speeds and feeds as roughers :eek: :D called FINISHRED FINISHRED link
very interesting and ill order one to see the result, they probably will be 30% higher in price but we'll see.
 
Here's another thought that just came to mind. If you know of any good carbide tool grinding shops, they can put that weldon flat on any carbide tool you want. That should open the door to you being able to buy what ever brand end mill you prefer.
 








 
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