[MBX5]

I got to the point where I thought I'd try some S-carb Ti coated endmills today...finally felt like I graduated into using some real tools.... that being said, I purchased some S-carb for aluminum and Z-carb for steel..... I had some ER32 tool holders, so I chucked up my sexy new 1/2" flat end mill, 3 flute, x 2"...went exactly by the book on the feed speeds and spindle speeds...I forget exactly what the IPM was but it was around 150 or so....flying compared to what I am used to... It ran for about 20 seconds, then Squeeeeeeeeeel, KaCHUNK....pop....and that was the end of my brand new $65 endmill...it shattered...

I looked at the cut, and it looked like it plunged too deep and I assumed my depth cuts were too deep....they were set at 1/4" (.5 x D) as show on SGS site....but my thought was I was being too aggressive.... So I adjusted my depth cuts to 1/8" and tried again.....30 seconds later....KaCHUNK and bye bye 2nd endmill....WTF!!?

Well after further review, I found that my ER32 collet tool holder let loose both times - the endmill sucked into the material, and pow.... Keep in mind that the SGS S-carb calls for some pretty aggressive feed speeds, which I adjusted for my max 10k RPM spindle...

After talking to someone I know about this who has done quite a lot of machining w/ Fadal machines - he recommended not using collet tool holders but use the standard end mill holders w/ a set screw....He claimed that Fadal is not rigid enough to use w/ these holders....

Now, that being said, I am a noob - and my holders are used and possibly turds... I purchased some brand new Techniks TE-06177S stubby ER32 holders and new collets - hopefully these will do...

My question - did I waste $750 on these holders and collets since it has been recommended to use standard holders for endmills?

[jamesu229]

Your problem has nothing to do with the rigidity of your machine. What is happening is the endmill is pulling out of your holder and probably spinning in it . As a rule, I only use collets for finishing processes(light cuts). The helix of the endmill is designed to exert a lifting force on the chip in order to evacuate it from the cutting surface. This creates an enormous amount of pulling force on the cutter. If you are stuck with the collet system, there is a way to increase the gripping capability of the collet. Wipe the shank of the endmill and the bore of the collet with a degreasing agent that will evaporate, such as denatured alcohol, acetone, or a similar product. Once all oils are removed, do not touch the shank of the endmill. this will provide a much better grip on the endmill. I would however see about some hard holders, possibly ebay.

[smittys800]

That is all I pretty much use are the ER32 holders. Biggset EM I use is 1/2".
I also use Data flute EM, only break them when I do something stupid.
My DOC is .2- .25 at say 100 IPM, lots of coolant and let it go

[Bwana Don]

After years of trying to get the collets to hold, I've switched to the solid toolholders with the setscrew for all endmills 1/2" or larger. Collets are a crap shoot IMHO. They must be clean and dry, no coolant or oil on them, I clean the collet and toolholder in alchohol. I also oil the threads on the holder for better torque when tightening the nuts.

If you can afford it, move to a shrink holder. I don't normally use any endmills with a weldon notch in a collet. I'm afraid my guys will spin it a 15,000 rpm and it will be unbalanced. My .02 cents on this.

Good luck, run em hard.

[Neal]

The general rule of thumb is NOT to use collets to hold endmills above a certain size. I recommend a maximum of 7/16 diameter. Beyound that, use solid end mill holders. If the end mill does not have a weldon flat on the shank then grind one in before using. THIS IS IMPORTANT to do!

Neal

[Delw]

The general rule of thumb is NOT to use collets to hold endmills above a certain size. I recommend a maximum of 7/16 diameter. Beyound that, use solid end mill holders. If the end mill does not have a weldon flat on the shank then grind one in before using. THIS IS IMPORTANT to do!

Neal

What Neal said. anytime I use a bigger than 3/8's endmill in a screw type endmill holder I grind a small flat for the lock screw. it doesnt have to be big just anything thats gives it a positive drive to keep it from spinning

[carbidecraters]

Going by the book means all things are perfect usually. Using a collet I bet the endmill sucked out of the collet and snapped. We use collets all the time for endmill use in aluminum when they get really dull they suck themselves down and break. Collets are an OK way to hold a endmill but an endmill holder is king.

[rowbare]

Are you getting the collets torqued down enough? An ER32 wants 100 ft/lbs of torque: http://www.techniksusa.com/metal/torque_chart.htm

Also you should probably pitch the collets that you have had trouble with. Once they have been spun or have let go like that, they are usually damaged.

bob

[SBC Cycle]

I only use solid holders for endmills. IMO, the only good reason to use a collet holder for an endmill is the cost factor. A dozen collet holders and a full set of collets is a lot cheaper than a dedicated holder for each size.

That said, I have a related question: How do you all feel about the ER32 collets? In our Fadals, we use the 100PG style collets and holders (Parlec brand) exclusively. When we tooled up our Haas lathe, it was suggested that we go with the ER32 style collets. "Once we try them we'll never go back"

They cover a wider range (more collapsible = less collets to buy) but that seems to be the problem I have with them. I can never get them tight enough or true enough. I will try some of the suggestions here to see if they can solve my holding problems.

I hope this isn't too far off track with the discussion. I figured if we were talking about collet holding power, I'd ask here.

[Neal]

SBC-
I prefer the ER style of collets. They have a longer bearing surface contacting the tool itself and the longer slower angle clamping surface holds the tools straighter therefore less tool rou out. Also the have mush higher gripping power.
I still prefer end mill holder for any end mill over 3/8 maybe 7/16".

Neal

[Andre' B]

When we tooled up our Haas lathe, it was suggested that we go with the ER32 style collets. "Once we try them we'll never go back"

They cover a wider range (more collapsible = less collets to buy) but that seems to be the problem I have with them. I can never get them tight enough or true enough. I will try some of the suggestions here to see if they can solve my holding problems.

I hope this isn't too far off track with the discussion. I figured if we were talking about collet holding power, I'd ask here.

I do not get into a lot of brute force roughing, generally very low runout is more important to me. So I prefer to use collets, but for the best run out and holding power in an ER collet you need to use one with a nomial size the same as the tool. So if holding a 3/8 end mill I use a 3/8 ER collet and not the 9-10 mm collet you find in most sets.

For even better runout and holding power look at a shallow angle system like HPI's MX holders or Rego-fix powRgrip system.

[Techman]

Didn't somebody used to make non-pull or no-pull collets? Possibly they were DA or TG collets. Anytime I use high helix endmills they go in an endmill holder as they really pull.

Also I have alot of trouble with students not "snapping" the collets in the cap. They drop the collet in the holder, put the tool in the collet, then tighten the nut on top.

[TheGreenMachine]

Are you getting the collets torqued down enough? An ER32 wants 100 ft/lbs of torque: http://www.techniksusa.com/metal/torque_chart.htm

Also you should probably pitch the collets that you have had trouble with. Once they have been spun or have let go like that, they are usually damaged.

bob

What he said. Using my ER32 collet wrench I tighten the nut as tight as I can by hand, I doubt I am getting to the 100ft/llbs. If I was doing some high performance roughing like you are I would make sure to clean the collet and end mill with a degreases as suggested and I would torque it down to the full 100ft/lbs. I wonder if anyone makes a socket with a 1/2 drive to fit a ER32 nut so you can use a torque wrench.

[Andre' B]

I wonder if anyone makes a socket with a 1/2 drive to fit a ER32 nut so you can use a torque wrench.

Somthing like this?
http://www.techniksusa.com/metal/torque_wrench.htm

[MBX5]

Thanks for the info guys.

I am pitching the holder that the tools slipped out of for sure.

I picked up 5 of these the other day:
http://www.techniksusa.com/metal/TE_...oolholders.htm

and also 2 new sets of ER 32 collets...

Anything 1/2" and above I will be using standard end mill holders, and will be using the collets for smaller stuff & drill bits.

I really like the SGS S-carb end mills so far...you can really run some fast travel speeds with them....I am still sick to my stomach that I snapped 2 brand new ones though....learning experience!

[TheGreenMachine]

Somthing like this?
http://www.techniksusa.com/metal/torque_wrench.htm

Andre' B, That would do the job.

MBX5, what was your radial engagement?

[Cartesian-xyz]

Ya Techman,
TG collets are still manufactured and can be purchased with a locking Weldon
grip key. I dont understand how anyone with quality holders and collets Even to
1.0 diameter could have problems with the tool removing itself unless it wasnt
properly tightened. Maybe it is just something I havent seen it my 32 yrs of
maching !!
Stephen

[Cmailco]

Don't use ER or TG for heavy cutting, period. If you want to use them for light finishing cuts, that's fine, but I typically delegate the ER's to drilling and tapping duties.
ER and TG have low radial stiffness and increased TIR under load. If you want to take heavy cuts at high revs, use a milling chuck like those from Lyndex-Nikken or Kaiser/BIG. They're a bit more expensive but are some of the best you can buy. A Lyndex milling chuck will set at .0002" TIR, 4" from the nose of the chuck, at better than 4x the gripping power of an ER or TG.

For smaller tools, an 8º collet system like Lyndex-Nikken VC, LSK or MMC series chucks. Kaiser/BIG has a really good "MegaE Chuck" that uses a similar collet system. It all depends on the kind of accuracy you need, the size of tooling you typically use and the materials you machine in your shop. Either way, the new chucks are good to 3 microns at 4D out. That's about twice as good as a good ER.

From the last aluminum job we ran:

1570 SFM (max RPM), Data Flute ALDH-series 1/2" 3 flute end mill, Nikken milling chuck, 7075-T6 aluminum, .5 adoc, .375 rdoc (120º TEA maintained), 500 in/min, 81 in³

I usually run these and a less expensive – but equally good end mill from Destiny Tool – at .75-1" rdoc on our Makino V33... humming right along and never a pull-out issue. Ti-6Al-4V, with 45 and 60º end mills, no issues.

I should be a Lyndex sales rep...