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What's new

Endmill Pulling out, and lots of heat - Live Tool Lathe

Shrink fit collets ER32 (8deg)- HAIMER

csm_Schrumpfspannzange_ER32_02_07f8c4804c.jpg




There are several "extension" type models here as well:

Shrink Fit Tool Holder

er11-srk_Enlarge.jpg


st_srk_Enlarge.jpg





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Think Snow Eh!
Ox
 
One thing that would concern me the most - before ordering - would be to find out how the ER collet body compares to a spring collet.

On my live toys (that take ER's) I have internal threads for internal nuts.
If I use a collet that has to get pinched way down, I cannot run my nut down that far.
I have Exsys hex nuts, and my hex ends up down inside the holder before it tightens up.
Same thing if I wanted to use a "tapping" collet - as they build those to the size of a compressed collet, rather than the expanded size.

So, depending on your nut configuration, I would want to find out the collet body size.


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Think Snow Eh!
Ox
 
Hopefully not too far off topic, but we just got a brand new Mazak quick turn 250MY at my work with new preci-flex 6k rpm power heads, a big step up from our old 3k rpm heads hopefully. Ours are capable of using the solid ER taper Weldon holders and all of the other adapters they make for them. Seems that they bolt in and hopefully have both a taper and flange contact style of adapter/holder. If the job was worth it for OP he could get one of these power heads with a Weldon adapter for his 5/8 endmill.

Has anyone used these style of power heads before? I'm excited to see the difference in rigidity with the dual contact adapters vs regular ER32 collets.

Sent from my moto g(7) using Tapatalk
 
I use ER32 on a BMT65 turret as well. Pullout happened to me once or twice and it was because my selected collet was just too big for the shank (10mm shank in 10-11 mm collet I think it was) so it was hard to tighten 100% and I needed length so only about 15 mm shaft was in collet. I also find that sealed collets have less grip/harder to tighten than the normal ventilated ones.
 
Lots of great ideas here for mitigating the problem, but I think the root cause is either something wrong with the live tool (end of life, lack of proper lubrication?), or operating overcapacity, to cause the heating. When it heats up it WILL loosen up, not to mention wearing out much faster. Having the cutter in a shrink fit collet or such may keep it from falling out, but if the holder taper swells, the collet could still spin in the holder, to suboptimal results.
 
and I am using a fancy, way too expensive, tool from Sandvik. I need to eliminate the pull-out issue.

Wow people actually use Sandvik endmills? I really like sandvik products but their prices are just ridiculous on solid carbide tools. If this job can afford to pay for a sandvik endmill surely you can afford a few more passes and lighter cuts with an average tool?

An endmill with sharper edge prep will have much lower cutting forces. Many steel specific endmills have slightly honed edge. Tools that are compatible with super alloys or titanium tend to be sharper.

ER32 collets can handle a lot of torque. If all else fails get a bigger wrench lol.
 
Lots of great ideas here that I will be trying/considering in the future. Thank you!

I finished up the small run of these square shafts today and I realized that I probably should have been a little more specific about the parts and what I've learned.

First off, the part is a 33" x 3-1/2" (stock size) shaft, one end gets turned to a spindle for a 15,000lb capacity wheel hub. The shaft end is turned to 2.930" and then milled to a 2.5" square with a taper on the end and a 3/4" keyway milled at the shoulder. Its for an Ag application.

The pull-outs were happening whilst trying to push the tool harder. Ran into problems at a 250 IPM feed, backed off to the 150 IPM keeping the same .025" DOC. When I really wrench on the collet, pullout on the tool isn't really an issue.

The Sandvik cutter is really just a Duramill WhisperKut re-branded since Sandvik bought Duramill. Its a trial tool from my supplier, and it works really nice even with the big ol' chipped flute from pulling out and slamming into the bed of the lathe haha.

I am running the side milling operation dry, good results. The live tool holder gets pretty warm though. When I run coolant, the tooling obviously stays much cooler. At this point, I am thinking I just run coolant and worry less about cutter life and more about the live tool holder life?

I'd love to upload a picture of the part, but as a forum noobie im having issues...
 
I'd love to upload a picture of the part, but as a forum noobie im having issues...

If you want, private message or email me, I'll pass on my email, and you can send the pics to me for posting.

And given the size of the work, I take back my guess that it's a Haas lathe you're working on. A pic of the machine would be nice too.
 
Lots of great ideas here that I will be trying/considering in the future. Thank you!

I finished up the small run of these square shafts today and I realized that I probably should have been a little more specific about the parts and what I've learned.

First off, the part is a 33" x 3-1/2" (stock size) shaft, one end gets turned to a spindle for a 15,000lb capacity wheel hub. The shaft end is turned to 2.930" and then milled to a 2.5" square with a taper on the end and a 3/4" keyway milled at the shoulder. Its for an Ag application.

The pull-outs were happening whilst trying to push the tool harder. Ran into problems at a 250 IPM feed, backed off to the 150 IPM keeping the same .025" DOC. When I really wrench on the collet, pullout on the tool isn't really an issue.

The Sandvik cutter is really just a Duramill WhisperKut re-branded since Sandvik bought Duramill. Its a trial tool from my supplier, and it works really nice even with the big ol' chipped flute from pulling out and slamming into the bed of the lathe haha.

I am running the side milling operation dry, good results. The live tool holder gets pretty warm though. When I run coolant, the tooling obviously stays much cooler. At this point, I am thinking I just run coolant and worry less about cutter life and more about the live tool holder life?

I'd love to upload a picture of the part, but as a forum noobie im having issues...

I know on our live tool holders you 'have' to run coolant to keep the holders cool.

If you really want to run the tool dry, direct the coolant away from the cut but keep the coolant on.
 
Well, my live toy tightening routine on my one machine is to use an impact.
I have Exsys nuts on the internal holders and they have a 15/16 hex on the ER25 nuts.
A deep well socket on a 3/8" cordless impact works super for that!

I doo the same on the Tornos that has 7/8 hex nuts on ER20's.

Now I don't have the heads "locked" when I doo this.
I either hold the socket with my hand to make it hammer, while the head is able to freewheel, or I have a wrench in my other hand holding the head from spinning.

I have been using this routine for many years and it has taken most of the busted knuckles out of the tool-change equazsion.
Live toy'ed lathes are the best place possible to tear up a hand, especially when trying to change tools!

I would NOT recommend this practice if you use the shot-pin in the head. (if so equipped)

And again - this only works for internal nuts with the hex drive.


IMG_2093_zps1d4a91b6.jpg




This next pic actually shows how the "tap" collets are too small to use with this type nut as it's the same as gripping a -.030 tool.

DSCN1654_zpstevt9pil.jpg


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Think Snow Eh!
Ox
 
Lots of great ideas here that I will be trying/considering in the future. Thank you!

I finished up the small run of these square shafts today and I realized that I probably should have been a little more specific about the parts and what I've learned.

First off, the part is a 33" x 3-1/2" (stock size) shaft, one end gets turned to a spindle for a 15,000lb capacity wheel hub. The shaft end is turned to 2.930" and then milled to a 2.5" square with a taper on the end and a 3/4" keyway milled at the shoulder. Its for an Ag application.

The pull-outs were happening whilst trying to push the tool harder. Ran into problems at a 250 IPM feed, backed off to the 150 IPM keeping the same .025" DOC. When I really wrench on the collet, pullout on the tool isn't really an issue.

The Sandvik cutter is really just a Duramill WhisperKut re-branded since Sandvik bought Duramill. Its a trial tool from my supplier, and it works really nice even with the big ol' chipped flute from pulling out and slamming into the bed of the lathe haha.

I am running the side milling operation dry, good results. The live tool holder gets pretty warm though. When I run coolant, the tooling obviously stays much cooler. At this point, I am thinking I just run coolant and worry less about cutter life and more about the live tool holder life?

I'd love to upload a picture of the part, but as a forum noobie im having issues...


early 90's mazak SQT18MS t32-3 here. Our vdi live tool holders are grease packed and need to be topped off every once in a while. coolant can still get in over time and water down the grease.
 
Boy, there's an idea that I never heard of before!
Most guys would never doo that to their collets, but ... whatever works!

I have some TG collets for capturing Welden shanks, but most don't have the notch anymore. (for strength reasons if nothing else)
Don't know if they make ER's with that option or not?





LH mills are only for side milling.







If it were me, I would run a rougher (corncob) endmill in there.
I run roughers as much as possible, especially in the live tooled lathes.
They take less trq, and they will beat the holder up less as well.
If you are just making flats, then you don't need a finisher side anyhow.
I save up my used roughers that I use for this app as they typically only use the bottom 1/4", and then I get them repointed, once, or maybe twice more.

Option B would be to stuff a small face mill in there.
IDK if you can buy a face mill adaptor for your tool heads, but a cpl of us have made our own.
Came up in a thread just a few weeks ago.


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Think Snow Eh!
Ox


While I was digging through my photobucket account, I grabbed this while I was there as well:

ER25ToShellMill1.jpg



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Think Snow Eh!
Ox
 
and it works really nice even with the big ol' chipped flute from pulling out and slamming into the bed of the lathe haha.

I honestly don't know how that could possibly have come all the way out of the holder without at least destroying the collet. Are you sure nothing besides the endmill has been damaged?

I have seen lots of "my endmill pulled out of my ER collet" threads in here over the years, and more often that not - perhaps exclusively - it's from American members using inch tools. Are you using a high quality brand name collet with true inch nominal sized bore? Lots of "budget" inch sized ER collets are remarked metric collets at the closest size.

The difference in grip on a 5/8" shank between a true 5/8" bore collet and a collapsed 16mm bore collet is very significant.

Here in metric land there are standards for shank sizes and collet bores, so a correct fit is mostly guaranteed, and it's not so easy to pull a tool out of an ER collet when the fit is correct and precise. Imperial collets and shanks are not so well standardised or controlled IME, but the odds of getting it right are improved by not buying cheap.

As you are using Sandvik - they have a series of high quality true inch sized ER collets. Maybe get one of those if you are not already using something like that.

When you are assembling, after cleaning everything thoroughly, put some light oil on the nut and the collet seat, but not on the collet or the tool. That alone makes a big difference to the collet drawing in properly.

Other than that, a long series 5/8" endmill with full length of engagement is pushing the limits of ER32. If nothing else works, going slower is all you can do.

As others have noted, live tools in general require some form of external cooling if running for any real duration. Get some coolant pointed at the body of the holder.
 








 
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