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HSK A63 vs cat40

yoke

Hot Rolled
Joined
Sep 26, 2013
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PA
In the final planning stage before adding a HMC and want get opinions of HSK vs Cat40.

I need new tool holders regardless because I am almost at capacity with my current Cat40 machines that will continue to be in use.

The cost is the same for all intents and purposes from the machine standpoint and the holders are only marginally more expensive for HSK.

15K spindle on the machine in question which doesn't necessitate the "High Speed" part of HSK.
Mostly Aluminum and Copper but occasionally 303 and 304. In the future I could see adding higher speed spindles which would make a case for going HSK now but I don't want to be giving up performance in the mean time.
 
HSK without question, way more rigid than the cat40 (unless it's dual contact). Much more suited to higher rpm's no studs to loosen or runout, no sticking in spindle taper, no fretting, ect...
 
CAT (NMTB, BT, yadda, yadda..) will last me the rest of my life. IF were even 40 years younger and had a serious facilty to equip?

I'd give a nod to HSK being worthy, and having its advantages but..

I'd also skip it as an evolutionary step...and go directly to "Capto". Initial cost be damned.

Going into any competitive exercise with the odds stacked as heavily in my team's favour as was possible, plus a bit, has ALWAYS paid-off.

Otherwise? Save yer money. Wait and see what comes better-yet than "all of the above". And cheaper.

40-taper JFW well-enough it will still "be there" for another human generation. Or three. Waaay more successful, universally useful, and enduring than MT, B&S, R8, etc, etc, etc,


2-armchair bystander's - or at least NOW I am - research worth...

Do Your Own Due Diligence. One-size-fits all is for adaptive-side genitalia. Not machine-tool spindles.
 
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This sounds like a bonus..

When a tool collision occurs using a conventional, steep-taper shank, the potential damage can be considerably greater than is true when using an HSK shank. Because a CAT (SK, BT) shank is solid steel, most of the collision load (and damage) transfers to the spindle. With its hollow design, however, the HSK shank acts as a fuse during collisions. When a cutting tool crashes, the toolholder breaks off and protects the spindle, thus reducing repair costs and machine downtime.

From here...

HSK: Characteristics And Capabilities. How HSK Differs From Standard Toolholders And What Advantages It Offers.


Personally, if I was adding 10 machines, I might go the newer fancier route.

If I already had Cat40's, and I was adding A machine, I'd probably be inclined to stick with what
I had...

If it was a production deal, where I was tooling up to run ONE thing or one family of things, I might go the newer fancier route.. You know.. Its going to run these 10 tools FOREVER!!! Job to job to job to job, I'd probably stick with I already have.
 
HSK 63 is larger diameter than CAT 40, but it's shorter and hollow. Does it weigh less than C40? If so does that allow faster toolchanger speed on the same machine that can be equipped with C40 or does the toolchanger need to be redesigned for faster speed? Does the larger diameter make it any stronger? The fusible link concept is appealing.

How hard is an HSK taper to repair if it's damaged?
 
HSK 63 is larger diameter than CAT 40, but it's shorter and hollow. Does it weigh less than C40? If so does that allow faster toolchanger speed on the same machine that can be equipped with C40 or does the toolchanger need to be redesigned for faster speed? Does the larger diameter make it any stronger? The fusible link concept is appealing.

How hard is an HSK taper to repair if it's damaged?

"All I know about that is what I read in the funny papers".

OTOH, I do read a few more funny-papers than the average bear, so..

A(ny) toolchanger surely needs "some sort of" re-tailoring, speed not alone, if even practical on whatever one HAS... or selects, new.

40-taper & siblings, one can usually repair/ re-grind in situ, average kit prolly already under yer own roof, and not even yer SECOND rodeo, already.

HSK, greater probability yah need a traveling specialist, ELSE pull the spindle and send it out.

That said, how often do YOU crash spindle stuff, any mount?

Same as wimmin, houses, two-or four wheelers, one sorta plans for the odd dis-assed-her, takes at least average care to avoid it, then "self insures" out of the productivity and/or convenience gains, yah?
 
How hard is an HSK taper to repair if it's damaged?

With the shallow taper angle it might be a little easier than for a dual-contact steep taper spindle, but I'd still probably want a specialist with the test gauges and experience to regrind it. The fact that you're supposed to have a little expansion of the taper when the clamping mechanism is engaged helps too.

I woudn't have any concern about regrinding a standard CAT taper myself, given the right grind apparatus (I would much prefer a proper moving slide over a stationary grinder and coordinated X-Z movement of the machine). So regular steep taper spindles have that going for them. If I was desperate, I might DIY a HSK, but I'd be sweating as I did it...
 
Here's a good read on the HSK interface: HSK: Characteristics And Capabilities. How HSK Differs From Standard Toolholders And What Advantages It Offers.

FWIW, I'll be checking out that site more thoroughly, looks like there's some good info there.

Yah but. 2005 copyright date, not the only similar article, not "news" for over a dozen years, already. All this has been put to the test on "many spindles", long-since. And it works.

HSK was "sold", and not wrongly, on - among other things, centripetal force tightening it's interface to the spindle, whereas.. NMTB/CAT/BT was - honestly and fairly actually measured - to start to degrade in bearing, precision of location, and driving grip at high RPM.

Despite which.. 40-taper has sojered-on to easily twice the RPM it was once thought to have as a practical upper-bound. No magic. No bottomless well. It cannot keep-on pushing the limit further-out.

But its demise was predicted waay too early on the "physics" of it all.

It still works. It still earns new "design wins". There isn't yet much else on-planet as flexible, cheap, nor of wider variety of "stuff" for the power it can manage.

That's not a criticism of HSK. Just realism on a tight budget as to value-remaining in vanilla 40-taper.

PROVE an economic advantage as well as a technical one, for the actual tasking at-hand (or planned), IOW. Or save yer money 'til HSK gets cheaper, or Capto does, or sumthin better than either MAKE them go cheaper...
 
I've read at least one report of a native Capto spindle cracking: C6 Capto spindle developing cracks (1)
Not sure if it's only a one-off, but I'd go HSK before I'd try any of the other "non steep taper" connections, if nothing else just for the relative commonality.

Helluva lot more than ONE damaged if not also cracked, just in the single thread source you cited. Also folk who are very pleased. And its an old thread too.

Near as I can tell, Capto is still good where it IS good. HSK was/is not 100% trouble-free, either.

Nothing ever is, quite. Not even those adaptive genitalia. And man, oh, man - talk about one helluva lot of field testing over long-years?

Not a one of us would even BE HERE if they didn't JF work, yah?

:)
 
Only drawback HSK 63 I have experienced it is more prone to have failure in tool change.
It do not have pull stud but it do not mean it can not fly off from spindle.
only major disadvantage HSK have is clamping fingers must go deep enough to reach corner from they should be pulling. If tool change is not adjusted exactly correct fingers can clamp from cylinder shape of holder and slip when spindle is started.
To prevent this tool clamping sensors must be adjusted below 0,25mm (0,01") tolerance
Because of that manufactures use expencive sensors not common limit swiches.
Maintenance cost of clamping unit is a lot more than BT/CAT
 
I've read at least one report of a native Capto spindle cracking: C6 Capto spindle developing cracks (1)
Not sure if it's only a one-off, but I'd go HSK before I'd try any of the other "non steep taper" connections, if nothing else just for the relative commonality.

Consider b axis mill turns. They've been around for two decades now.

Here in Europe, KM never really caught on so those are extremely few and far between and can be ignored for the sake of argument. That leaves every b axis mill turn machine to have either a HSK or Capto spindle. Observationally, it seems that capto is perhaps twice as common as HSK on these machines.

That's a LOT of capto spindles out there, for 20 years. If they were particularly prone to failure, I feel that we would hear a lot more about it.
 
If I was you and I had other HSK machines in the shop I'd try to buy an HSK horizontal.
If I didn't have any HSK machines I'd get a Cat/BT40 in a horizontal...

I think rigidity wise Big Plus Bt40 is comparable to HSK63. Its not a fair comparison in my shop because my BT40 machine is not as rigid of a structure / design as my HSK63 machines but holder vs holder. Also I think the advantage of HSK63 is in 5 axis there are a hell of a lot more options for extended reach and tapered reach holders where as on a horizontal if you design your tooling right you will rarely use a holder over 4" / 100mm gage length


(I have 3 cat40 , 1 bt40, 3 hsk63 machines,7 bt30 )
 
Who is stocking HSK in a horizontal? Usually they are all special order from the factory?

Okuma has some on the way that are unsold. I never really considered making the change until I knew I wouldn't need to wait 6 months.

I have been impressed with Haimer tool holders and was talking with them at IMTS about tooling up a new machine. I was surprised to hear they don't do any dual contact holders. The sales guy was saying that the worldwide sales of dual contact has been trending down and they don't want to invest in a product line that isn't growing. I was very surprised to heat that.
 








 
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