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Endmills snapping at holder nose tip

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
Fretting on the front of the shank and collet is because of movement. Hydraulics do not clamp until at least 3/8-1/2" in the bore socket. Front of the tool holder bore is brazed to the outer nose, so it cannot move or clamp.

This is where shrink win. With shrink you have 100% clamping the entire bore length and 100% all around. The very extreme front of the tool holder is clamping just as hard as the back of the tool holder. Maybe just a little less depending on the thickness at the nose.

2 questions
Frank, do you make a "roughing" shrink fit? something with a short guage length, maybe a bit more girth too?
or would you moreso recomend a side lock even for these hsm type toolpaths?

ANYONE
in saying that, how would most people mill out a part like this? again im almost 20 years of big ugly manual machines, mostly repairs and only self taught on the cnc mill stuff, learning is earning!

1" indexable and ramp down the whole outside and bore?
3/4 solid hsm or big step over?
plundge mill?
(should be cast i know! ;p)

my goals would be process reliability, low coonsumable cost per part (i dont mind upfront costs) and not beating the hell out of the machine
machine is a 2009 vf2 (brand new condition 450 hours) 20hp 10,000rpm direct drive(my understanding is the torque rating on this spindle is very low, 45lb? but the hp/torques rating stays flat almost all the way to the top rpm) standard and through spindle coolant availible, air blast availible.
 

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
One curious thing I noticed about hydraulic holders is they are not very stiff. I used 2 or 3 different types and they all seemed to allow for a lot more tool deflection. I think this could be due to the fact that while the liquid pressing against the inside of the bore is incompressible, the bore itself is actually rather thin piece of steel tube. So this allows some movement of the shank deep inside the bore.

I find those only good at light to medium roughing. At heavy loads I have seen pull outs.

So either shrink fit, or side lock for heavy stuff.

ive never has a measurable pull out on my shunk tendoE hyd. holder and run for long periods at 100% haas power in aluminun (3/8 kenn kor 5 doing hsm paths, excessive amounts of aggresive parts roughing) but your very right that they are not laterally stiff and deflect under any amount of load. but the cuts seem so smooth with it,
maybe my er and milling chucks suck (very likely) but whenever i try hsm in them the tool screams bloody murder/chatter
 

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
I think 10 k is to much rippems I would run it 5 k .02 step over 1 1/2 ramp angle 70 inches per minute 400 ipm backfeed and cut all the parts no problem
Don


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when your mentioning ramp angle, are you refering when sinking into the bore, or the OD as well? im just not understanding ramp and light side stepover (note, i have not seen it all!)
 

D Nelson

Stainless
Joined
Jan 7, 2015
Location
Missouri Ida
Ramp angle when you are going into the top surface it looks too aggressive to me. It just kills the Endmill and I run flood coolant all the time. I have never seen air blast ever increase tool life
Don


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D Nelson

Stainless
Joined
Jan 7, 2015
Location
Missouri Ida
On the older Haas. Controls you can put 400 ipm and start increasing to 800 and nothing actually happens it shows big numbers but that’s all
Don


Sent from my iPhone using Tapatalk Pro
 

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
On the older Haas. Controls you can put 400 ipm and start increasing to 800 and nothing actually happens it shows big numbers but that’s all
Don


Sent from my iPhone using Tapatalk Pro

ya its "says" it can cut at 650ipm, but you had better have a runway for that, any corners at all and your way under the posted rate. in fusion360 i put a 0.015" tolorance and 0.015" smoothing to help shorten the code, put on hsm and g187 p1 and it still slows significantly at lots of parts of the tool path.
horses for courses, im just trying to learn the best track to un mine on :) the spindle torque/hp curve points me to hsm tool paths(imo), but the motion control is only so so for that, but the low end grunt is not there on this machine either. looks like on the newer 10,000 plus spindles they went 30hp to help that bottom end out alot.haasspindl.jpg
 
Joined
Nov 15, 2005
Location
Illinois
2 questions
Frank, do you make a "roughing" shrink fit? something with a short guage length, maybe a bit more girth too?
or would you moreso recomend a side lock even for these hsm type toolpaths?

Yes,
I am currently making all popular sizes in 4.5, 3.5, and 2.75" gage length. The 2.75" gage length is the shortest you can make while still allowing all heat shrink machines to work on your tool holder. Will be on the site in a month or two hopefully.
 

cameraman

Diamond
Joined
Nov 24, 2014
ya its "says" it can cut at 650ipm, but you had better have a runway for that, any corners at all and your way under the posted rate. in fusion360 i put a 0.015" tolorance and 0.015" smoothing to help shorten the code, put on hsm and g187 p1 and it still slows significantly at lots of parts of the tool path.
horses for courses, im just trying to learn the best track to un mine on :) the spindle torque/hp curve points me to hsm tool paths(imo), but the motion control is only so so for that, but the low end grunt is not there on this machine either. looks like on the newer 10,000 plus spindles they went 30hp to help that bottom end out alot.View attachment 327282


https://www.haascnc.com/content/dam...-machine-pdp-binder-/VF-40T Series Binder.pdf

^^^ these are the new spindle curves; but to my mind they all need to be scaled down by a factor 2 as they are all listed as 200% spindle load ? Not sure if your vintage of machine is also 200% spindle load graph ?


__________________________________________________________________________________

Tangential but not HAAS bashing (still the home team (right ?) - but seeing what's possible on some other controls can be quite illuminating.[Without sounding too snotty/ snooty ].

TNC 620 contouring control | HEIDENHAIN control

This is the Heidenhain 620 (page) not blinged out as much as theHH 640 - but never the less has serious capability,

but what's interesting are the features on the control that can actively dampen low frequency vibrations, + handle "High jerk -rate" acc/decc for much more "dynamic" tool paths.


Dynamic Precision: the new MVC function for vibration damping - YouTube

^^^ [Machine vibration control ]. ~ Interesting how they graphically represent the tool pitching and vibrating and TCP being reined in. (Wonder how they would go about collecting visual / spatial data on that in a high speed way. ).

AND compensate acceleration dependent position errors

+ Load adaptive control / position adaptive control

+ And map out and compensate cross talk between servo/ drive combinations on different axes.

For regular 3 axis work or multi axis,

+ OCM (optimized contour milling) - Can't find a concise or discrete video for that but the 2nd embedded video of

TNC 620 contouring control | HEIDENHAIN control

this ^^^ page explains OCM very well, + cutting parameters + a ton of software tools to help with different materials and collision avoidance even with the next contour level. All on the control.

New for OCM: cutting data calculator and deburring - YouTube

^^^ Short Heidenhain vid on tool life and faster high feed optimized tool paths ... many other vids and tutorials.

__________________________________________________________



Kinda makes you think , well what would happen with a low bandwidth control that has very little "Positional". spatial or dynamic awareness.

So you can run it ( your HAAS) real slow so everything catches up (electronically).


Titan and Kennametal and others are not doing these kinds of really fast feed rates and special tool (adaptive) paths on older HAAS equipment using Harvey 1 or 3 or Kor 5 etc. ? OR are doing these more recently on machines that have more advanced (high bandwidth and more positionally/ dynamically aware) controls ?
~ (the rigidity and size of force loops (in cut) are pretty much of a muchness in this case - I suspect.).

It's interesting that you bought a Schunk (hydraulic) tool holder to mechanically compensate vibration dampening.

And interesting you have the high feed options all turned on and Fusion 360 tweaked as best you can.

Still don't dig that sleeve but think the holder in principal seems allright :-) (full intended diameter). - interesting what folks are saying about the way the tool pitches / deflects in those hydraulic holders.

Never the less seems you spindle is exceeding the torque required but the sleeve is slipping in cut. ? [well for some of the time ???].
 

Wsurfer

Cast Iron
Joined
Apr 1, 2013
Location
Austin Texas
FWIW
Brother S500 standard spindle
1018 steel
6 flute 1/2", 1.5" Loc YG-1 end mill. Maritool side lock
Ramp 1deg. 4000 rpm
Cutting 1" deep, 10krpm 5% radial 400 IPM.

I don't do production, so can't comment on tool life
 

cameraman

Diamond
Joined
Nov 24, 2014
<snip>

What gives?
I’ve run these several times now and am getting the same result over several jobs.
Gone as hard as 0.075woc 1”doc 10,000rpm 400ipm (air blast) in 1045steel
Seems no matter how hard or soft I run it’s the same’ish metal removal before breaking.

I mean mr titan runs the same endmill at one million Ipm and rpm right?? :)

Run the kor5 aluminum cutters way harder and they won’t die. Same tool holder and mill.


Tips, advice?
Grew up on old school manual equipment, self taught CNC. And the learning gets $$$$ some times


Just for a lark,

and in comparison to other things...



This is fun to watch - boxed ways, high spindle torque +50 taper , and general set for old school big cuts. - good dampening of a heavy cut.

What I noticed with Titan's of CNC while they had mainly HAAS equipment they would very rarely or only once in a blue moon actually cut steel or tool steels; everything was mainly centered around aluminum and titanium, and then later with different machines the tough aerospace alloys.

for comparison HAAS universe...



Cast iron (65-45-12 ) - demo on the VF 2 ^^^
 

cameraman

Diamond
Joined
Nov 24, 2014

Looking at that spindle curve for your machine and you looking to get the fastest cycle time,

seems that spindle is optimized for or at 6000 rpm. ( well 5900 rpm :-) ) [I could be wrong; but that seems to be the best balance between speed and torque for higher rpm on that 10000 rpm spindle. ].

Curves are for "maximum rating" ... so again real values towards continuous 100% could be half of that or even less.

So at 6000 rpm the real value maybe 8.5 ftlbs rather than 17 ftlbs, and the power output at 6000 rpm for what you have could be 10 HP not 20 HP.
 

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
3:43 in the haas vid, is it just me or is the chamfer tool bent when it stops spinning???
looks like hass is using schunk as well. the reason i use the schunk is 1. i happen to have it, bought on a whim, and it seems to be the one that dampens vibe the best, as i said other tool holders screetch terribly it seems.
schunk has 2 lines of hyd. tools, the cheaper tendoE series is intended for use with reducer sleeves and they only make it in a 3/4 rceiver hole. the premium schunk are all specific bore tools and made from tool steel

"IMPOSSIBLE” Kennametal Speed Test In STEEL | DMU 50 | PowerMill | Vlog #89 - YouTube
heres titan with a 3/8 in his machine 19,600rpm 1000ipm 0.95depth 0.041 stepover, pretty crazy cutting with a tiny tool. if i could do half that with reasonable tool life i would be happy! thats what i was aiming for when i was breaking the nedmills (half of his cut)

cut my woc to 0.01875 in the ms project and so far so good. cut a bunch of 4140htsr today at 7000, 400ipm (not thst it actually reaches that speed) 0.6 oc 0.01875woc. same endmill roughing strong. sounds good. still seeing fretting on the shank but no snapping yet.

ill likely pick up a few more endmills and an assortment of holders to play around nect time this job comes through. sounds like ill need to step up to a larger endmill to get better job times though.
neat thing about playing with the cheaper/smaller tools is you can test tool holders and find points of failgure sooner, with hopes of then applying that to larger tools down the road vs/ masking the problem with a bigger tool. IMO
 

cameraman

Diamond
Joined
Nov 24, 2014
3:43 in the haas vid, is it just me or is the chamfer tool bent when it stops spinning???
looks like hass is using schunk as well. the reason i use the schunk is 1. i happen to have it, bought on a whim, and it seems to be the one that dampens vibe the best, as i said other tool holders screetch terribly it seems.
schunk has 2 lines of hyd. tools, the cheaper tendoE series is intended for use with reducer sleeves and they only make it in a 3/4 rceiver hole. the premium schunk are all specific bore tools and made from tool steel

"IMPOSSIBLE” Kennametal Speed Test In STEEL | DMU 50 | PowerMill | Vlog #89 - YouTube
heres titan with a 3/8 in his machine 19,600rpm 1000ipm 0.95depth 0.041 stepover, pretty crazy cutting with a tiny tool. if i could do half that with reasonable tool life i would be happy! thats what i was aiming for when i was breaking the nedmills (half of his cut)

cut my woc to 0.01875 in the ms project and so far so good. cut a bunch of 4140htsr today at 7000, 400ipm (not thst it actually reaches that speed) 0.6 oc 0.01875woc. same endmill roughing strong. sounds good. still seeing fretting on the shank but no snapping yet.

ill likely pick up a few more endmills and an assortment of holders to play around nect time this job comes through. sounds like ill need to step up to a larger endmill to get better job times though.
neat thing about playing with the cheaper/smaller tools is you can test tool holders and find points of failgure sooner, with hopes of then applying that to larger tools down the road vs/ masking the problem with a bigger tool. IMO

DMU 50 titan cut 1.jpg <--- click to enlarge

So this is Titan's spindle or was ? Don't know what he did with his DMU 50 3rd gen ? :-)

So Titan kinda mis-spoke a bit in the video as the DMG MORI SpeedMaster spindle has a hell of an output in KW or HP at the highest rpm. (It's one of the distinctive features of that spindle.).

The torque is naturally lower 'cuz physics.

The torque of Titan's DMU 50 20K rpm spindle at 19000, ish 19,600 is about 9 ft lbs or 12 NM (Newton Meters) the scale on the chart is logarithmic or doubles every linear square or increment on the Y axis.

The output is somewhere between 33 and 47 Horse Power at 19,600 rpm with a torque of 9 ft lbs.

Good eye , I spotted the Schunk tool holder too :-) in the HAAS video.



On your machine you have realistically 10 horse power at 5 ftlbs at 10,000 rpm, ~ that's why I think 6000 rpm (actually 5850 -ish) - may give you better balance for metal removal at a higher rate, - power vs available torque. [at least according to a squiggly graph for what may be your spindle.]. but with new fangled tool paths and "wonder tools" who knows :-) ??? :D
 

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
View attachment 327352 <--- Click to go "BOOM"

So this is Titan's spindle or was ? Don't know what he did with his DMU 50 3rd gen ? :-)

So Titan kinda mis-spoke a bit in the video as the DMG MORI SpeedMaster spindle has a hell of an output in KW or HP at the highest rpm. (It's one of the distinctive features of that spindle.).

The torque is naturally lower 'cuz physics.

The torque of Titan's DMU 50 20K rpm spindle at 19000, ish 19,600 is about 9 ft lbs or 12 NM (Newton Meters) the scale on the chart is logarithmic or doubles every linear square or increment on the Y axis.

The output is somewhere between 33 and 47 Horse Power at 19,600 rpm with a torque of 9 ft lbs.

Good eye , I spotted the Schunk tool holder too :-) in the HAAS video.



On your machine you have realistically 10 horse power at 5 ftlbs at 10,000 rpm, ~ that's why I think 6000 rpm may give you better balance for metal removal at a higher rate, - power vs available torque. [at least according to a squiggly graph for what may be your spindle.].

your attachment does not work :(
 

cameraman

Diamond
Joined
Nov 24, 2014
your attachment does not work :(

It might take time to take I'll fix it.


And again ,

DMU 50 titan cut 1.jpg <click to enlarge,


^^^

So this is Titan's spindle or was ? Don't know what he did with his DMU 50 3rd gen ? :-)

So Titan kinda mis-spoke a bit in the video as the DMG MORI SpeedMaster spindle has a hell of an output in KW or HP at the highest rpm. (It's one of the distinctive features of that spindle.).

The torque is naturally lower 'cuz physics.

The torque of Titan's DMU 50 20K rpm spindle at 19000, ish 19,600 is about 9 ft lbs or 12 NM (Newton Meters) the scale on the chart is logarithmic or doubles every linear square or increment on the Y axis.

The output is somewhere between 33 and 47 Horse Power at 19,600 rpm with a torque of 9 ft lbs.

Good eye , I spotted the Schunk tool holder too :-) in the HAAS video.



On your machine you have realistically 10 horse power at 5 ftlbs at 10,000 rpm, ~ that's why I think 6000 rpm may give you better balance for metal removal at a higher rate, - power vs available torque. [at least according to a squiggly graph for what may be your spindle.].

^^^ same as before
 

Stirling

Cast Iron
Joined
Dec 11, 2013
Location
Alberta canada
so 2.5x my spindle, lots a powa! boom :p

still tho im not running out of hp, its the endmill thats snaping

funny thing is ill push their kor5 endmill at 100% spindle load and it never breaks, and its longer. same tool holder same machine, bla bla. heck, i even had a coolant inturuption and it was stir welding for 2 inches. big ol ball on the end, took it out, soaked it in battery acid for a week and chisled the welded ball off. still using that endmill! not the best finishers, but those kor5 have been very impresive. the litle chips that come off tho fit perfectly through the coolant return tho! so watch out for that!
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
At this depth of cut where should it break when loads too high?
This is not .050 deep.
Not going to do force diagrams and stresses but this seems normal and expected.
Transverse rupture is exceeded not in the flute area but at the solid hinge or bend at the nose.
The one inch area is loaded all the way up and happy to bend or curve during cutting.
That bend ends way fast at the end of a good holder.
Bob
 
Last edited:
Joined
Nov 15, 2005
Location
Illinois
If you are running an endmill or operation where the tool breaks often it is best to use an oversized hydraulic holder and use a sleeve. That 1 time out of 4 where the broken endmill kicks back will ruin the sleeve and not the tool holder.

Had a customer profiling parts that were laser cut or plasma cut, with a 1/2" cutter. Tool life was low and very unpredictable. Recommended our 3/4 hydraulic holder and 3/4-1/2 sleeve. Ran great and tool life increased, but still remained unpredictable.
 








 
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