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gambler
03-14-2018, 01:22 PM
which do you guys use for holding end mills? r8 collets or r8 end mill holders with the set screw?

Mcgyver
03-14-2018, 01:27 PM
depends on the size and how aggressively you're going to work them, small = collet, large = endmill holder. Whats large? dividing line is probably 5/8's for me

MrWhoopee
03-14-2018, 01:30 PM
which do you guys use for holding endmills? r8 collets or r8 end mill holders with the set screw?

Depends on size, collets are fine for most situations. Large diameter and/or long endmills with heavy cuts result in stronger down forces (from the helix) causing the mill to pull out of the collet. That's when you need a holder with set-screw. I'm a bit baffled by endmill holders under 1/2" dia., but I suppose there are situations where they might be needed.

Dan Dubeau
03-14-2018, 01:39 PM
Let your work dictate your toolholding. Sometimes the extra reach is nice with EM holders, sometimes the collet shines for reduced stickout. It's very handy to have both available. If your budget says one or the other, get a good set of collets. They're just more versatile.

JoeLee
03-14-2018, 01:59 PM
I always use colletts, but I don't hog aggressively. I have a few end mill holders and never liked them because they tend to load the cutter to one side when the set screw is tightened. For roughing I suppose it's OK. Lighter cuts and finish dimensions I prefer colletts.

JL.................

BCRider
03-14-2018, 02:06 PM
When I first got my new R8 spindle mill I tested the grip of the R8 collets. One of the end mills in my assortment is a 1" six flute cutter with a 3/4" shank. I figured that was a good "worst case scenario". Installed in the 3/4" collet and given a good pinch on the drawbar without going mondo crazy. If I had to estimate the torque I'd call it somewhere between 15 to 20 foot-lbs. I tend to err on the side of things that results in a torque that only needs a firm tap of a lump of lead to break the collet free instead of a heavy blow that is death to the spindle bearings over the long haul.

I started making nearly full diameter cuts with this older and used but not abused end mill. A felt pen witness mark between the end mill and the collet was added to see if there was any slip. I quit when I got to about 1/8 x nearly the full 1" of cut with a fairly aggressive but still happy sound coming from the cutter and chips. You guys know that sound. A crisp hissing sound but without the sort of growl and somewhat ripping sound that comes from pushing up to too high a chip load. At that point I figured that was as much as I'd ever need.

Sometimes the friction thing doesn't work on smaller cutters. So I repeated the same test for 1/2" and 3/8" cutters. I used the 9/16"x 1/2" for the half inch collet and the 7/16 x 3/8 for the 3/8" collet just so it was the worst case situation in all cases. None of them slipped at all that I could see.

Since then I've used just the collets with confidence.

It's different for something like a flycutter or large face mill. For those I stick to full R8 shanks.

My old mill/drill had an MT3 spindle. The MT3 collets that came with the mill did not generate a lot of friction on the end mill shanks. So I bought or made up screw style holders. Bought in a couple of cases where the overhang was very low and made for the sizes where the overhang was very high in the commercial versions.

In all of this the main idea is to limit the overhang and thus the flexing that can increase chatter and flexing. If collets will give you the friction you need so they don't slip then you're not going to reduce the overhang by any more than that.

gambler
03-14-2018, 02:16 PM
thanks again, I'll get some collets. do I need to worry about the .0006 tir ones, or are standard ones ok?

754
03-14-2018, 02:52 PM
I use a Clarkson AutoLoc with threaded end end mills, and the R8 setscrew type...... Weldon shank.

Mcgyver
03-14-2018, 03:13 PM
thanks again, I'll get some collets. do I need to worry about the .0006 tir ones, or are standard ones ok?

like .0006 is supposed to be good? what are the "standard" ones?

1/2 a thou run out is not going to matter aggressively cutting with say a 1/2 endmill, things get loaded and cutters flex....but it seems a lot of run out for a collet. If using very small endmills it would be too much imo

dalee100
03-14-2018, 03:52 PM
Hi,

R8 Collets are just fine for anything up to Bridgeport sized machines. Properly tightened, these machines it's nearly impossible to push a collet hard enough to slip.

You only really need a 6 piece set, 1/8" to 3/4" by 1/8's for end mills, (maybe a 5/16" if you want to use carbide). Yay for standard sized shanks!!!! Which ones to buy? Honestly, everybody who makes collets has sold me at least one bad one. From no names to Hardinge. R8 collets are a commodity item and tends to manufactured to commodity price points. My advise is to open wallet, see how much you are willing to spend, then spend that much. But don't be surprised if one or two doesn't meet your expectations........ I look for .0005" or less. I don't think I've ever seen over .001" even in no-name collets. More runout will create shorter tool life in larger tools, and may even cause tool breakage for tiny tools. Like 1/16" of smaller. If you don't use a steady diet of small tools, not much to worry about.

Mcgyver
03-14-2018, 03:58 PM
Hi,

R8 Collets are just fine for anything up to Bridgeport sized machines. Properly tightened, these machines it's nearly impossible to push a collet hard enough to slip.

.

not true. With a 3/4 or 7/8 endmill in a collet on a 1 - 1.5 hp machine you can definitely move the cutter. Its not that it slips like a drill bit can slip, its starts pulling out of the collet so your DOC changes.

Gary Paine
03-14-2018, 04:27 PM
I suggest you never trust a collet to securely hold on to a dovetail cutter. I got away with it until I didn't.:o

old mart
03-14-2018, 04:31 PM
I use mostly er25 collets, then threaded to fit Clarkson Autolock, Osborn Titanic and Acramill holders and sometimes R8 collets. As the mill is not used to take heavy cuts, I have never had a cutter move.
If you run a machine within an inch of its life, you deserve all you get, this is a "home shop forum" after all.

ncjeeper
03-14-2018, 04:45 PM
depends on the size and how aggressively you're going to work them, small = collet, large = endmill holder. Whats large? dividing line is probably 5/8's for me
X2.

JohnMartin
03-14-2018, 04:46 PM
which do you guys use for holding end mills? r8 collets or r8 end mill holders with the set screw?

Neither.

Sometimes I use NMTB 40 end mill holders. Sometimes I use TG100 collets in an NMTB 40 collet chuck. Even better than the TG100 collets are the TG100NP collets, which have a plug that fits the Weldon flat. Sometimes DA or WW collets, sometimes LB or 00 collets, sometimes Morse taper end mill holders. Rarely, depending on circumstances, in a drill chuck. Depends on the machine and the end mill size.

With quality end mill holders and quality end mills, I've never felt that the end mill was loose enough in the holder that a set screw would drive it off center - at least not enough to matter. To me. And I'd prefer it to be slightly off center against the risk of it pulling out of a collet. Unless it's a "no pull" collet, but I don't know if they make them in R8.

Seastar
03-14-2018, 04:53 PM
In my very limited expierence I have never had an end mill slip in an R8 collet. Even with very aggressive cuts.
But then I have a small 1.5 HP mill that can only put that much power into the end mill.
Bill

3 Phase Lightbulb
03-14-2018, 05:12 PM
I've never had any holding issues with R8 collets in a Bridgeport. IMO, your speed/feeds are way too high if your end-mills are slipping or extending out, or are being pushed in. Or maybe the collets are junk.

dalee100
03-14-2018, 05:50 PM
I suggest you never trust a collet to securely hold on to a dovetail cutter. I got away with it until I didn't.:o


not true. With a 3/4 or 7/8 endmill in a collet on a 1 - 1.5 hp machine you can definitely move the cutter. Its not that it slips like a drill bit can slip, its starts pulling out of the collet so your DOC changes.

Hi,

You missed the "properly tightened" part of the statement. In 25+ years of running shop floors, nearly every time an operator told me a tool slipped in the holder it was because they did not tighten the tool holder, (collets and endmill holders both), properly for the job at hand. End mill holders were the worst offenders. The few times it wasn't because of poor collet tightness, it was because of improper tool mounting in the collet or a damaged collet.

Tightened correctly, you can stall a 1hp mill easily if you get stupid with your cut and not pull the tool out. I've done it.

3 Phase Lightbulb
03-14-2018, 06:22 PM
Hi,

You missed the "properly tightened" part of the statement. In 25+ years of running shop floors, nearly every time an operator told me a tool slipped in the holder it was because they did not tighten the tool holder, (collets and endmill holders both), properly for the job at hand. End mill holders were the worst offenders. The few times it wasn't because of poor collet tightness, it was because of improper tool mounting in the collet or a damaged collet.

Tightened correctly, you can stall a 1hp mill easily if you get stupid with your cut and not pull the tool out. I've done it.

Agreed.. I also wondered how anyone could break the collet alignment pin and it's obvious now :)

frankie
03-14-2018, 06:25 PM
If you are using a smaller type machine keep in mind that an end mill holder will increase the side load and perhaps push the head out of tram. The longer length produces a lever effect. When I was employed I always use 40 taper solid holders as I felt they provided more rigidity.

frankie

CCWKen
03-14-2018, 06:33 PM
The 3/4" cobalt rougher is my favorite end mill. The only trouble I've had with it is pulling a five pound block of steel out of the vise. :eek: It didn't budge in the collet. I don't own any end mill holders but if I were to buy any it would be because I needed an extension or for a monster-sized end mill. Perhaps some of you guys are girly tightening the drawbar or your tools are filthy dirty (full of chips). Clean the quill taper once in a while too. :cool:

CCWKen
03-14-2018, 06:42 PM
When I was employed I always use 40 taper solid holders as I felt they provided more rigidity.

Doesn't matter about taper. It's only as rigid as the end mill you're using. How rigid is it on 1/8" end mill? :cool:

RB211
03-14-2018, 06:46 PM
Just use shrink fit tooling :p


Sent from my iPhone using Tapatalk Pro

platypus2020
03-14-2018, 07:02 PM
I’ve used R8, ER32 and din 6388 style collets, I’ve never had an end mill move.

J Tiers
03-14-2018, 07:09 PM
Collets work until they don't.

Yes, I HAVE had the EM crawl out of collets. I still use collets, but I also use holders. I have 3MT holders and no 3MT collets. I have both for 2MT.

Mark Rand
03-14-2018, 07:42 PM
If it's weldon shank, I use endmill holders with grub screws. If it's Clarkson threaded shank, I use a Pozilock endmill holder. If it's a plain shank, I use ER32 collets. If it's a shell mill, I use a dedicated mounting. All in a 2hp NMTB30 spindle. Haven't yet had the need to get a shrink fitting holder or grind a flat in a carbide endmill shank, but I've thought about the posibility...

thaiguzzi
03-15-2018, 12:25 AM
If it's weldon shank, I use endmill holders with grub screws. If it's Clarkson threaded shank, I use a Pozilock endmill holder. If it's a plain shank, I use ER32 collets. If it's a shell mill, I use a dedicated mounting. All in a 2hp NMTB30 spindle. Haven't yet had the need to get a shrink fitting holder or grind a flat in a carbide endmill shank, but I've thought about the posibility...

Funny, i was watching an Adam Booth video yesterday, going through an assortment of stuff in a toolbox, and he came across some Clarkson threaded end mills. "What are these? Never seen anything like these before"....
Up until this century, Clarkson type milling cutters is all i ever saw in the UK...

lakeside53
03-15-2018, 12:42 AM
EM holder are nice if you bother to index the tool offsets and store them in the dro (or cnc). I have both, but mostly use collets (Lyndex). Never ever had an EM slip and I hog the crapola out of steel and AL. If you use round (no weldon style relief) carbide EM in EM holders, you can have issues with the set screws gripping -grind a flat on the shank.

BCRider
03-15-2018, 03:33 AM
You guys with NMTB 40 machines are just showing off to make the rest of us feel bad....:D

You guys with the Clarkson setups are just out to make the rest of us feel inferior.

I was given the go ahead to buy some milling stuff for work many years back. After some cruising through the early internet I spec'ed a Clarkson chuck and end mills and was given the go ahead. I got to use the chuck and mills a fair amount and LOVED the whole setup. But it is simply too dear to use for a home shop environment when I've got a drawer full of Weldon shank end mills already. But that aside the Clarkson stuff is primo goods and I would recommend it to anyone starting from scratch.

MattiJ
03-15-2018, 03:59 AM
EM holder are nice if you bother to index the tool offsets and store them in the dro (or cnc). I have both, but mostly use collets (Lyndex). Never ever had an EM slip and I hog the crapola out of steel and AL. If you use round (no weldon style relief) carbide EM in EM holders, you can have issues with the set screws gripping -grind a flat on the shank.

I think in many cases the reason for slipping endmills (or taps) is not torquing the collets enough tight.

For example Rego-Fix recommendation for ER32 collets is 132Nm or 100 ftlbs and "not to exceed maximum recommendation" is 170 Nm or 125 ftlbs.
Good luck trying to tighten the ER32 nut with the typical er nut wrench to 170 Nm!

dalee100
03-15-2018, 09:00 AM
Hi,

Perhaps the best of both worlds tool holder, (and my personal favorite), was a NT50 to R8 holder I had to use at one shop. I used it most often in an old K&T No.4 vertical mill. To change a tool you had to remove it from the machine, then use a hex wrench to reach down inside the NT50 holder to loosen the 7/16-20 SHCS to remove the R8 collet. A real pain in the backside to use. I always wondered who thought that was a good idea and how much drinking did it take to reach that conclusion.

754
03-15-2018, 10:42 AM
Maybe Clarkson is more of a British and Canadian, and the Colonies thing..

A.K. Boomer
03-15-2018, 10:56 AM
The 3/4" cobalt rougher is my favorite end mill. The only trouble I've had with it is pulling a five pound block of steel out of the vise. :eek: It didn't budge in the collet. I don't own any end mill holders but if I were to buy any it would be because I needed an extension or for a monster-sized end mill. Perhaps some of you guys are girly tightening the drawbar or your tools are filthy dirty (full of chips). Clean the quill taper once in a while too. :cool:

I second this - I do have larger R-8's but they tend to get very thin walled with anything over 3/4 so that's really the largest endmills i have and iv pushed them some with no problems - im not into production at my home shop too often and when i am it's stuff im not having to remove tons of material...

Iv only got 1 1/2 hp but even if I had 3 I would be just fine with the R-8 system in fact I love it and have never had one slip on machines with 3 ponies...

as stated before i save my drawbar threads for when i need them - little 1/8" endmills barely get tightened in comparison to 3/4" two flutes

the leverage ratios of medium threads pulling on a taper is incredible - if your ever having trouble with slipping in "normal" usage you might try this,
1; put a drop of oil on your drawbar threads once in awhile, and towards the bolt head where it meets your spindle spline,
2; carefully clean and lube the spindle taper
3; get some brake clean and clean the endmill shank and also the inside of the collet with a rag, a rag and a pinkie finger should fit as your not having to worry about doing this to the smaller stuff due to the unit pressures being so high even if you just put a medium amount of torque on the drawbar...

you do all this - and you have now drastically increased your "traction control" over the endmill even more,

iv never had to take it to step 3 but routinely make sure im not running dry on my drawbar threads and taper...

BCRider
03-15-2018, 02:46 PM
Even better than oil on the drawbar threads would be a wipe of good grease. No running away and it gives lower friction so we can get the tension force we want with less torque and less wear on the threads.

And yeah, I heartily agree with the other things to aid with a good strong grip.

hornluv
03-15-2018, 02:58 PM
Most of the responses have been about collet slippage, but here's another point. If I'm making a lot of parts with multiple tool changes, I don't want to have to touch off my tools every time I change them, so I use endmill holders or ER collet chucks. Then I know where the end of my cutter is when I put them back in the spindle (assuming you have a DRO with tool offsets). That said, for most one off jobs, I use my R8 collets.

thaiguzzi
03-16-2018, 01:25 AM
You guys with NMTB 40 machines are just showing off to make the rest of us feel bad....:D

You guys with the Clarkson setups are just out to make the rest of us feel inferior.

I was given the go ahead to buy some milling stuff for work many years back. After some cruising through the early internet I spec'ed a Clarkson chuck and end mills and was given the go ahead. I got to use the chuck and mills a fair amount and LOVED the whole setup. But it is simply too dear to use for a home shop environment when I've got a drawer full of Weldon shank end mills already. But that aside the Clarkson stuff is primo goods and I would recommend it to anyone starting from scratch.

Even today, you can buy the Clarkson type collets and collet chucks at reasonable prices. Posilock, Vertex, Osbourne, to name but a few. I have a Vertex collet chuck with Vertex metric and imperial collets (4 of each), and it was not more than a hundred bucks ( a few years ago!)....

BCRider
03-16-2018, 11:40 AM
Most of the responses have been about collet slippage, but here's another point. If I'm making a lot of parts with multiple tool changes, I don't want to have to touch off my tools every time I change them, so I use endmill holders or ER collet chucks. Then I know where the end of my cutter is when I put them back in the spindle (assuming you have a DRO with tool offsets). That said, for most one off jobs, I use my R8 collets.

That's an excellent point. If I ever get to that point I think I'd like to look at buying or making a bunch of Tormach style set screw holders for the end mills. And I believe that it also requires a special collet with the nose ground off flat. But it ensures consistency and I like the idea of increasing the base like length of support by being drawn up against the spindle nose.

BCRider
03-16-2018, 12:06 PM
Even today, you can buy the Clarkson type collets and collet chucks at reasonable prices. Posilock, Vertex, Osbourne, to name but a few. I have a Vertex collet chuck with Vertex metric and imperial collets (4 of each), and it was not more than a hundred bucks ( a few years ago!)....

I did a little looking as a result of your post. You're right and the chucks are not that bad a price at all. But I found it hard to find sources for the end mills and other cutters. And when I did the prices were up there. So while in so many ways the threaded shank end mill with the proper chuck is so ideal and fixes all the issues noted in this thread I'm afraid that it's a fair bit more costly option.

It's funny but for a fellow with a manual mill that uses a DRO a threaded shank chuck and end mills would actually be the perfect answer to consistent cutter positioning. The inherent qualities of the threaded shank tools that are centered with the collet is the PERFECT method for best centering and very consistent depth of mounting. And while the cutters cost more it would avoid the need for multiple holders. So in the end the whole setup would actually be cheaper. And holding zero on any cutter in the collection would be only limited by the number of cutter zeros that can be programmed into the DRO.

So if/when I go for a DRO I may just keep going and get a Clarkson, Posilok or some other such chuck after all. But for now it simply doesn't make financial sense.

dalee100
03-16-2018, 01:27 PM
Most of the responses have been about collet slippage, but here's another point. If I'm making a lot of parts with multiple tool changes, I don't want to have to touch off my tools every time I change them, so I use endmill holders or ER collet chucks. Then I know where the end of my cutter is when I put them back in the spindle (assuming you have a DRO with tool offsets). That said, for most one off jobs, I use my R8 collets.

Hi,

Endmill holders aren't all that good either. Maybe +/- .010" for dead length at best. Flats aren't placed with any great accuracy nor is overall length real close either. I can do as well setting dead length with a ruler.

If you need to set lengths with an real hope of accuracy, you need a fixture.

lakeside53
03-16-2018, 11:11 PM
Not sure I understand your post. You mount the EM into the holder then calibrate the offset length. You can change the holder with EM at will. I find they register within a couple to small number of 10ths.

BCRider
03-16-2018, 11:39 PM
I think dalee is thinking that you're swapping the mills in the holder. Not putting an EM in the holder and leaving it there after touching it off and saving it in a memory position and swapping the whole holder with that particular cutter in it.

754
03-17-2018, 12:27 AM
I believe that using Clarkson type endmills of good pedigree, the lengths are within a few thou.
Meaning if you break one and replace it, no tool setting.
Try that with Hu Flung Dung end mills..

dalee100
03-17-2018, 12:59 PM
Hi,

Yes I was, my bad and apologies for miss reading.

thaiguzzi
03-18-2018, 02:44 AM
I did a little looking as a result of your post. You're right and the chucks are not that bad a price at all. But I found it hard to find sources for the end mills and other cutters. And when I did the prices were up there. So while in so many ways the threaded shank end mill with the proper chuck is so ideal and fixes all the issues noted in this thread I'm afraid that it's a fair bit more costly option.

It's funny but for a fellow with a manual mill that uses a DRO a threaded shank chuck and end mills would actually be the perfect answer to consistent cutter positioning. The inherent qualities of the threaded shank tools that are centered with the collet is the PERFECT method for best centering and very consistent depth of mounting. And while the cutters cost more it would avoid the need for multiple holders. So in the end the whole setup would actually be cheaper. And holding zero on any cutter in the collection would be only limited by the number of cutter zeros that can be programmed into the DRO.

So if/when I go for a DRO I may just keep going and get a Clarkson, Posilok or some other such chuck after all. But for now it simply doesn't make financial sense.

Bar the sub 1/4" specials, i've never bought a new slot drill or end mill. All are/were S/H. Must be plenty out there S/H.
Then buy a T&CG.....:cool:

BCRider
03-18-2018, 01:25 PM
Bar the sub 1/4" specials, i've never bought a new slot drill or end mill. All are/were S/H. Must be plenty out there S/H.
Then buy a T&CG.....:cool:

Please don't tempt me you enabler ! ! ! ! :) I was leaning towards a T&CG for a while and was even looking over prices. But then I had a "WTH AM I DOING! ? ! ? ! ?" moment of clarity and realized how many new end mills I could buy for the cost of even a used T&CG. Now I keep an old short tin for worn or chipped end mills that I'll likely hand re-sharpen for use as boring bars..... they work quite admirably at that FWIW....

The real reason for keeping them is that I may do up something with my 5c spindexer to see if I can at least re-sharpen the ends. But if that doesn't work then it's definitely "boring bars" for them.