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Side lock or ER holder?

Captdave

Titanium
Joined
Sep 24, 2006
Location
Atlanta, GA
Having problems with a carbide 1/2" 3 flute x 2.0" EM slipping down when heavy profiling in 6061. The EM is only cutting to 1.6" deep so its choked up in the holder and a flat wouldn't be of use.

Without much experience using larger ER holders with end mills, I would guess that it would provide better holding power but would like to hear from experienced users.
 
I would(have) grind my own locking flat and use an em holder. IME I've had less problems with pullout & chatter using solid em holders.
 
Having problems with a carbide 1/2" 3 flute x 2.0" EM slipping down when heavy profiling in 6061. The EM is only cutting to 1.6" deep so its choked up in the holder and a flat wouldn't be of use.

Without much experience using larger ER holders with end mills, I would guess that it would provide better holding power but would like to hear from experienced users.

Sidelock with flat. I'd even go as far to grab a roughing endmill from either Destiny or Maritool for the job. Less side pressure. Lots of companies sell endmills with flats for aluminum.
 
An ER-32 takes some pretty serious tightening torque on the nut to really hold on. I do my roughing and profiling with an er-32 and 1/2 EM all the time with no problems. A side-lock holder isn't gonna give you the same low run-out as a quality ER....

Try really bearing down on the ER nut (within spec anyways)
 
I found this article to be informative. Rego Fix invented and owns the patents on ER collets, hopefully they know. I de-grease/oil the collet ID and tool shank with some non-residue cleaner too. After pulling a 5/8 EM out of an ER-32, I started following those directions and haven't had any more trouble. Depending on the manufacturer, the torque for an ER 32 is supposed to be 80 - 100 ft lbs. That can be reasonably estimated as "as tight as I can possibly make it" with the short whimpy wrenches usually supplied.
 
When using solid carbide end mills the runout is a key factor in tool wear. Using a hydraulic milling chuck or shrink fit holders minimizes runout, and holds with much higher grip than any ER collets.
 
I think many people misunderstood.
OP is using. A side setscrew holder on an endmill that is chucked deeper than it should.
so the screw is pushing against the cylindrical portion of the tool. Hence the tool is pulling out of the holder.

Simplest solution is to grind a new flat on the shank.

Or use a collet.

Sometimes i put a 3/4 3fl hi-helix end mill into a ER32.
I acrually grease the threads and collet-nut interface to get as much grip as possible and use a propper 1foot wrench.

Never had anything slip out of that.
 
I can't believe this works at all...

Most carbide end mills made for aluminum do not have flats. This is because they run at high RPMs and balance is key. You should be at 8000 RPM or more for a .5" end mill. I've never had much luck running Weldon holders over about 6000 RPM.

If this is HSS, I suppose you can grind in a flat.

Get an ER32 collet chuck. I've never had a tool move in one when properly torqued. I use tap collets, but even taps never spin in regular collets in my experience.
 
Collet and holder quality play a big role in gripping your tools properly. Which ever route you choose make damn sure it's quality tooling, hence "QUALITY"
 
I can't believe this works at all...

Most carbide end mills made for aluminum do not have flats. This is because they run at high RPMs and balance is key. You should be at 8000 RPM or more for a .5" end mill. I've never had much luck running Weldon holders over about 6000 RPM.

If this is HSS, I suppose you can grind in a flat.

Get an ER32 collet chuck. I've never had a tool move in one when properly torqued. I use tap collets, but even taps never spin in regular collets in my experience.

Good endmill holders get the run out down to less than .0003-.0004. Good enough for roughing IMHO.
 
Good endmill holders get the run out down to less than .0003-.0004. Good enough for roughing IMHO.

Oh yeah a 2" long 1/2 hi-helix EM will deflect 5 thou no problem.. so even a 1 thou runout will not screw things up too much...
I personally like to use weldon holders for roughing- they have smaller nose dia on the end and also there is usually a 1/2" 45deg champfer that lets you chuck deeper and gives better clearance than said ER32
 
I'm using a 1/2" x 2" 3 flt rough/finish EM from Lakeshore at 8,000 RPM (the sweet spot for torque) at 125 IPM 25% step over and 1.6" LOC with the tool as far up in the holder as possible.

I'll be running this job again next week so I'll try a few of the suggestions.
 
Oh yeah a 2" long 1/2 hi-helix EM will deflect 5 thou no problem.. so even a 1 thou runout will not screw things up too much...

Yeah, it is possible to run it so it deflects 5 thou, that's no problem. But doing so leads to two major sources of problems:

First, it is heck on the tool life. It isn't hard to see that applying the repetitive stress hammer to the tool enough to make it bend 5 thou thousands of times a second can't be helpful for the tool life. But hey, forget that visual. With tooling manufacturer's saying you can lose 10% of tool life for every tenth of runout, viewing a thousandth as no big deal is one thing but adding another 5 thou to that is asking for trouble.

Second, it is an open invitation to chatter. Tool deflection is a major cause of chatter. When the tool deflects, that leaves a "bump" that subsequent flutes travel over creating a periodic change in cutting force and depth of cut. That is the resonant vibration that is chatter.

Tooling manufacturers recommend keeping deflection under 0.001" to avoid chatter, and that's why that limit was chosen in G-Wizard. Above 0.001" of deflection, it's only a question of whether you're running at a spindle rpm that happens to be resonant with the chatter.

Cheers,

BW
CNC Machinist Cookbook: Software and Information
 
Yeah, it is possible to run it so it deflects 5 thou, that's no problem. But doing so leads to two major sources of problems:

First, it is heck on the tool life. It isn't hard to see that applying the repetitive stress hammer to the tool enough to make it bend 5 thou thousands of times a second can't be helpful for the tool life. But hey, forget that visual. With tooling manufacturer's saying you can lose 10% of tool life for every tenth of runout, viewing a thousandth as no big deal is one thing but adding another 5 thou to that is asking for trouble.

Second, it is an open invitation to chatter. Tool deflection is a major cause of chatter. When the tool deflects, that leaves a "bump" that subsequent flutes travel over creating a periodic change in cutting force and depth of cut. That is the resonant vibration that is chatter.

Tooling manufacturers recommend keeping deflection under 0.001" to avoid chatter, and that's why that limit was chosen in G-Wizard. Above 0.001" of deflection, it's only a question of whether you're running at a spindle rpm that happens to be resonant with the chatter.

Cheers,

BW
CNC Machinist Cookbook: Software and Information

Well. Tool deflection is a part of machining process.
The guy is running his EM at 8000RPM and 120 IPM daking 1.6DOC and .125 WOC.

I would bet that 1/2" 3Fl 2" long EM is gonna deflect ATLEAST 5 thou anyway.
Yesterday i ran Niagara HPEM with same parameters but 1.375" DOC, 0.05" WOC at 10000 RPM and 280IPM, here is a link if anyone is interested.
So at the bottom pocket ended up being around 3 thou per side smaller than on top.
Keeping deflection under 1 thou is nice but this means keeping your cuts waay below what your tool and machine can handle (talking about production equipment here)

EDIT:
Captdave,
You got nice MRR- 26 in^3, mine was slightly lower only 20 ;)
 
What about a hydraulic chuck or milling chuck?

Very sturdy indeed.

Nobody has mentioned the TG (tremendous grip) series collets yet. They are the middle ground between an ER (extended range) collet and the hydraulic chuck, milling chuck, or shrink fit holders.

The shallower taper of the TG collets gives then much more clamping force than an ER collet, but have limited clamping diameter range on each collet size.
 
I found this article to be informative. Rego Fix invented and owns the patents on ER collets, hopefully they know. I de-grease/oil the collet ID and tool shank with some non-residue cleaner too. After pulling a 5/8 EM out of an ER-32, I started following those directions and haven't had any more trouble. Depending on the manufacturer, the torque for an ER 32 is supposed to be 80 - 100 ft lbs. That can be reasonably estimated as "as tight as I can possibly make it" with the short whimpy wrenches usually supplied.


80 to 100 ft lbs as i remember is quite a good pull on a 2ft long 1/2 drive Mac torque wrench, not sure if
the short wrenches will get you near it but it might be interesting to check just how much the factory wrench
can put on it with a normal pull.
 
Its milling some really deep lobes with a HSM pocking op so its not a constant engagement where the spindle load settles down at a given point but I'll bet its near or at 100% power maybe slightly over.

The lobes get a dedicated finish tool afterwards so any deflection is removed, just need to get them roughed quickly. I do like Lake shores rough/finish tools as they break up the chips well so less change of re-cutting a big thick chip and breaking the tool and fewer time cleaning the machine out.
 








 
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