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Are milling chucks obsolete?

My robodrill has a BT30 14kw spindle, and I have had pullout (not runout) issues with an ER32 twice. I run very aggressively in roughing applications, so I changed to a big daishowa hydraulic holder, and it never happened again.
What sized hydraulic? Did you use one with a reducer collet/sleeve?
 
As far as budgeting goes, I think I'm in a different world here in Taiwan, because there are like 100+ machine tool builders in my city and dozens of tool holder manufacturers here as well. So I can get locally made tool holders at about 25% of the cost as in the US or EU. The only type I can't seem to find locally is stubby hydraulics in BBT30.
A lot of the more advanced holders made there are garbage. You get what you pay for. You're asking all the right questions but you're still getting drawn into the local "buy cheap" mentality.

The problem with milling chucks, hydraulics, etc is that they're unforgiving if a tolerance is blown in manufacturing. The holder needs to be trashed because it can't correctly grip a tool... in stark contrast to a tapered collet holder where a blown grinding job simply means bad runout. But what happens a lot over there is that they don't get trashed. The managers turn a blind eye and ship the bad product to the customer and shrug when shit hits the fan.

I've used a milling chuck made by one of the better companies there and a 1/2" aluminum endmill pulled out almost immediately.
 
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A lot of the more advanced holders made there are garbage. You get what you pay for. You're asking all the right questions but you're still getting drawn into the local "buy cheap" mentality.

The problem with milling chucks, hydraulics, etc is that they're unforgiving if a tolerance is blown in manufacturing. The holder needs to be trashed because it can't correctly grip a tool... in stark contrast to a tapered collet holder where a blown grinding job simply means bad runout. But what happens a lot over there is that they don't get trashed. The managers turn a blind eye and ship the bad product to the customer and shrug when shit hits the fan.

I've used a milling chuck made by one of the better companies there and a 1/2" aluminum endmill pulled out almost immediately.
See, now this is exactly the kind of thing that makes me paranoid. I read the other thread with the guy who gets tool holder fretting, and I'm thinking there is really no way to check that any of the tool holders will perform as expected until measured. Last time I bought a set of tool holders from this local company 2 years ago, they were all nearly perfect in measured runout and the external quality looked nice as well. But I didn't have the tools at the time to check torsional clamp strength and pullout resistance.

I also bought a set of cheap Chinese Alibaba tools to compare, imported them into Taiwan, spent like 300 dollars to see if they were viable. Nope. They claim 5 microns runout and measure at 30 microns for the SK16s. Horrible. Maybe OK for a flycutter?

I'll probably end up buying a set of BBT30s for the new machines, then I'll have to exhaustively check their taper contact, flange contact, runout without tool, runout with tool, runout at 4xD, torsional gripping strength and pullout strength. I'll make a detailed post on this forum when I have the results, which will hopefully be in a few weeks.

If the Taiwanese made tools have good runout but low grip force, that must mean the collet taper angle isn't perfect. I figure a good grind job would actually make the big end slightly too small, because it expands more than the small end when the collet is expanding it.

@Orange Vise You don't have to say their full brand name, but does the company you bought that milling chuck from start with An or Sy? BTW thanks for your feedback and advice so far in this thread!
 
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SK will absolutely hold better than ER due to the steeper taper. You can test this yourself or call the lyndex salesman and they will perform the test in front of you.
Yes sir. Lots of great info in this thread. Just need that votec school to rerun their tests with SK and all equal stick outs
 
SK will absolutely hold better than ER due to the steeper taper. You can test this yourself or call the lyndex salesman and they will perform the test in front of you.
Yup, this is the same reason the PG holders grip so well. Really shallow taper means with equal pushing force in on the collet you get much more squeezing force radially.
 
What sized hydraulic? Did you use one with a reducer collet/sleeve?
1/2" ID and no reducer sleeve. I've attached a photo from their catalog with the specs.

I use Guhring hydraulics in my Haas with one of their fancy collets. Running 17-4 H900 all day long w/ 1/2" and 3/8" endmills.

Link to that: https://www.guhring.com/ProductsServices/SizeDetails?EDP=9042430200400

Honestly, the big d and Guhring are my least favorites in the shop. I have a Kennametal Hydroforce in my Integrex, and it's a CHAMP. Can't screw up with the torque because the screw bottoms out, which is how most folks ruin a hydraulic holder. I run a 1/2" reducer sleeve, and it just blows me away. The holding force is great, vibration dampening is great, and the entire holder is rock solid. I run a 1/2" duramill endmill @ 75% stepover & 1XD at 40 IPM in H900, and it's completely silent. I get about 700 minutes of cutter life. It's bonkers. The holder was 1200 bucks, and I think it's the best holder investment I've made.
 

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My robodrill says otherwise. You can easily hold a 1/2" diameter endmill in a BBT30 spindle. Let's pretend you're using a high helix 1/2" endmill in 6061 and roughing with a 10% radial stepover at 1.5XD. Would you hold that in an ER collet? I wouldn't...
a 1/2" endmill roughing at only 10% radial? I would absolutely run that tool in an ER holder all day long. But I would never rough in aluminum at 10% stepover.
 
a 1/2" endmill roughing at only 10% radial? I would absolutely run that tool in an ER holder all day long. But I would never rough in aluminum at 10% stepover.
Only 10% radial @ .005" chip load per tooth @ 1.5XD is a lot of spindle load and cutter engagement, especially on a BT30 spindle. We're talking a minimum IPM of 90ish and a max of around 150ipm if you factor in chip thinning. Maybe I do things more aggressively, but I wouldn't trust an ER collet in that kind of application, especially long term. Don't get me wrong, I also use ER holders, but never for aggressive roughing based on how I program parts.

We all do things very differently. I tend to go balls to the wall in roughing applications, and I always use dedicated roughing/finishing tools. I like the security of using tools that give me the lowest possible chance of spontaneous failure. My hydraulic holders have never failed me, but ER collets have from time to time.
 
minimum IPM of 90ish and a max of around 150ipm if you factor in chip thinning
I have my default settings for 1/2" roughing aluminum at 2xD, 20% radial, 15k RPM, 200IPM on my BT30s. I'm glad you shared because I always thought others were pushing their machines even harder like 300+ IPM and I was worried I was being too conservative. It's good to know others are in the same ballpark. I usually use side lock holders for roughing, but I've started to use hydraulics more these days. I haven't had a tool pull out of a hydraulic holder, but I have had tools pull out of ER and SK holders when slotting steel.
 
Honestly, the big d and Guhring are my least favorites in the shop. I have a Kennametal Hydroforce in my Integrex, and it's a CHAMP. Can't screw up with the torque because the screw bottoms out, which is how most folks ruin a hydraulic holder. I run a 1/2" reducer sleeve, and it just blows me away.

I wonder if the larger nominal ID with reducer is key. You're getting a larger chuck body and more fluid volume and surface area, so probably higher gripping force.

I have a 1.00" Tendo lying around that I'm going to experiment on with a 1/2" reducer sleeve and see how it fares.
 
I wonder if the larger nominal ID with reducer is key. You're getting a larger chuck body and more fluid volume and surface area, so probably higher gripping force.

I have a 1.00" Tendo lying around that I'm going to experiment on with a 1/2" reducer sleeve and see how it fares.
This.

F=P*A make A bigger and F has to increase as well.

The larger and small holders use the same hydraulic pressure inside of them, but same pressure over more area because larger ID means more force. The reducer sleeve transfers the greater force from the larger holder down onto the smaller shank. It's almost always better to run a larger bore hydro with a sleeve. You get the higher clamping force but also the benefit of only junking up the sleeve if you snap a tool in one vs the holder itself.

Plus with sleeves you have the ability to run safelock sleeves and pin lock sleeves for added pullout protection.
 
This.

F=P*A make A bigger and F has to increase as well.

The larger and small holders use the same hydraulic pressure inside of them, but same pressure over more area because larger ID means more force. The reducer sleeve transfers the greater force from the larger holder down onto the smaller shank. It's almost always better to run a larger bore hydro with a sleeve. You get the higher clamping force but also the benefit of only junking up the sleeve if you snap a tool in one vs the holder itself.

Plus with sleeves you have the ability to run safelock sleeves and pin lock sleeves for added pullout protection.
Safelock doesn't play games, those things are legit.
 
I have my default settings for 1/2" roughing aluminum at 2xD, 20% radial, 15k RPM, 200IPM on my BT30s. I'm glad you shared because I always thought others were pushing their machines even harder like 300+ IPM and I was worried I was being too conservative. It's good to know others are in the same ballpark. I usually use side lock holders for roughing, but I've started to use hydraulics more these days. I haven't had a tool pull out of a hydraulic holder, but I have had tools pull out of ER and SK holders when slotting steel.

It's all based on what machine and cutting tools you have at your disposal. I based those on a 3fl generic aluminum endmill. If you had a 5fl endmill and ran 1200 sfm & .006 ipt, you could easily go well over 300 IPM. Then again... your machine acceleration might not be able to keep up with that, which is always a problem. Also, most shops don't even come close to 200ipm because they're terrified of it. Regardless, sounds like you're getting after it pretty well. Turn up the heat if you think it's conservative and see what happens, the worst-case scenario is a broken endmill or scrapped part.

What improvements have you noticed switching from side lock to hydraulic?
 
Heres something to think about... how often do you see a damaged ER32 holder? I think the 80-100 or so foot lbs for ER32 is very conservative. I believe this number is probably calculated to avoid deforming collets that are significantly larger then the tool being used, or deforming collets with very small tools. But if you have the right size collet that fits tool perfectly, and were talking larger tools, theres no reason IMO why you cant crank them tighter. Im not usually this type of guy, but I do have a piece of pipe next to my ER32 wrench and crank them pretty friggin tight the odd time i need to use a 3/4" endmill. Always use bearing nuts too. Never have an issue with tools pulling out or damaged holders.
 
Heres something to think about... how often do you see a damaged ER32 holder? I think the 80-100 or so foot lbs for ER32 is very conservative. I believe this number is probably calculated to avoid deforming collets that are significantly larger then the tool being used, or deforming collets with very small tools. But if you have the right size collet that fits tool perfectly, and were talking larger tools, theres no reason IMO why you cant crank them tighter. Im not usually this type of guy, but I do have a piece of pipe next to my ER32 wrench and crank them pretty friggin tight the odd time i need to use a 3/4" endmill. Always use bearing nuts too. Never have an issue with tools pulling out or damaged holders.
Good point. There's certainly a bit of forgiveness in the torque values, but there's a line you don't want to cross. I once had an employee crank down on an ER16 so hard that the holder cracked in the collet taper/threaded section. He was trying to prevent a tap from spinning in a standard collet instead of using a tap collet. He no longer works for me for obvious reasons.
 
Heres something to think about... how often do you see a damaged ER32 holder? I think the 80-100 or so foot lbs for ER32 is very conservative. I believe this number is probably calculated to avoid deforming collets that are significantly larger then the tool being used, or deforming collets with very small tools. But if you have the right size collet that fits tool perfectly, and were talking larger tools, theres no reason IMO why you cant crank them tighter. Im not usually this type of guy, but I do have a piece of pipe next to my ER32 wrench and crank them pretty friggin tight the odd time i need to use a 3/4" endmill. Always use bearing nuts too. Never have an issue with tools pulling out or damaged holders.
If you're using high quality stuff, its clean, degreased, and assembled correctly. Using a bearing nut I'd have no issue going 130-140lb-ft on an ER32.
 
Heres something to think about... how often do you see a damaged ER32 holder? I think the 80-100 or so foot lbs for ER32 is very conservative. I believe this number is probably calculated to avoid deforming collets that are significantly larger then the tool being used, or deforming collets with very small tools. But if you have the right size collet that fits tool perfectly, and were talking larger tools, theres no reason IMO why you cant crank them tighter. Im not usually this type of guy, but I do have a piece of pipe next to my ER32 wrench and crank them pretty friggin tight the odd time i need to use a 3/4" endmill. Always use bearing nuts too. Never have an issue with tools pulling out or damaged holders.
What are the tool runout values with 100 foot pounds of tourque applied to the nose of an ER tool holder?

I worked with guys that would hit the ER spanner with a hammer even with little endmills. I guess if you need to beat the shit out of a holder to keep the tool tight you should be looking into a different style tool holder.

The Nikken SK collet chucks come with a tightening handle that is six inches long so we’re probably sub 40 ft pounds and have runout values under .00025 100% of the time. I’ve had zero pullout with SK16 with a max endmill size of 1/2. I do have some ER11 holders from Rego fix for 1/8 shank tools those I tighten with one finger on a spanner. The runout with those well cared for holders is usually around a tenth. Any more tourque on a little holder will deform that little nose.
 
Yes the ER16s will split overtime if you over tighten them. Seen that happen at last shop i worked at, I sawed wrench off to prevent guys from over torquing those lol.

But the 32 size can really take a beating. And does hold reasonably well if you crank em tight.
 








 
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