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[JAMES GABEL]

I have a boss that says that cnc machines can bore a .750 dia hole at 1100 ipm and hold tolerance of .0002.  Has anyone ever seen this before?

[Reko]

I bet your boss was never a machinist.

[Guest]

Simple answer is no

 

Can you mill that fast, yes..under the right conditions..a hole at that size the machine could, 1. never accelerate to that IPM and 2. not compensate accurately even if it could

 

 

 

 

 

I bet your boss was never a machinist.

 

Nope but I bet he's a Trump supporter who isn't living in the real either  

[Matthew Hajicek - Singularity]

I have a boss that says that cnc machines can bore a .750 dia hole OR MOVE AT at 1100 ipm and OR hold tolerance of .0002.  Has anyone ever seen this before?

 

More accurate fiss.

 

 

Ask him to show you how it's done!

[crazy^millman]

I have a boss that says that cnc machines can bore a .750 dia hole at 1100 ipm and hold tolerance of .0002.  Has anyone ever seen this before?

 

Was he saying use a 1" endmill and the bore is 24" deep holding that tolerance. Was that with a .01 endmill in .01 thick material where it has room to generate an arc and get up to speed.

 

I have a part running for a customer that was taking 100 hours to rough. We got it down to 40 hours. One manager said we needed to do it in 10 hours. We are taking 7200lbs of aluminum and bringing it down to 500lbs in 40 hours in 2 operations. The MMR was 180 cubic inches a minute. Everyone has good pie in the sky ideas and how it should be, but you just can't beat the laws of physics plain and simple.

[Goldorak]

you will have to run the boring head over 300000rpm to be able to do this fast .....

[Goldorak]

but, you can feed pretty fast with a burnishing tool  

[Matthew Hajicek - Singularity]

I think the boss is talking about friction stir welding.

[jlw™]

The MMR was 180 cubic inches a minute.

Muck Fe! What cutter and specs please?

[crazy^millman]

On 9/2/2016 at 2:13 PM, jlw™ said:

Muck Fe! What cutter and specs please?

 

2" Cutter 3 Flute with 1.2" step over 24000 rpms and 1200 imp. Was and still is throwing chips 40 feet away from the machine. Need to cut 6 of these a year. ROI just on the roughing was 240 hours. Total return for the this company was over $750k with  over a $100k just on the roughing for this part. 

 

[mkd]

"only" 90 Hp.

[taperlength]

I have a boss that says that cnc machines can bore a .750 dia hole at 1100 ipm and hold tolerance of .0002.  Has anyone ever seen this before?

 

 

Yes,  many times I have seen bosses that make outrageous claims.

 

 

Oh, you mean has anyone seen this done.  

[Watcher]

Ron,

 

What's the total HP available on this machine by the way?

 

There's a practice that started after WW2 where machine builders guarantee maximum spindle power, constantly, for 15 min... In this part the spindle stays loaded with 90HP for hours, so I assume the maximum power available in the machine is at least 30% higher than 90HP.

 

The HSM advisor screenshot shows that the spindle power is being used at its fullest. I think the machine power of this equipment is in the advisor settings lower than the real power available in the machine, thus showing it using 100% of the spindle power.

 

Did I get this right?

[crazy^millman]

Well i can tell you this it was pegged over 85% spindle load for most of the 40 hours. Machine is a Italian machine with an 840D, HSK-63A that can run up to 27000k on the spindle. Those who have wore the hot chips down the back and necks standing 30 foot away can also tell you how it was cutting. You would think Aluminum would cool down after that far. Nope it doesn't. :scooter:

[Fred @ Slate Industries]

The scenario of someone "Over selling" there product still continues.

 

Your doing the right thing , keeping the peace and just figuring out what is actually a capable feed rate / load etc.

[Watcher]

Well i can tell you this it was pegged over 85% spindle load for most of the 40 hours. Machine is a Italian machine with an 840D, HSK-63A that can run up to 27000k on the spindle. Those who have wore the hot chips down the back and necks standing 30 foot away can also tell you how it was cutting. You would think Aluminum would cool down after that far. Nope it doesn't. :scooter:

Yes... Actually I put it wrong... The machine builders usually support spindle overload of something around 115% for 15 minutes....

 

You said 85% constantly... 115-85=30%

 

So yes, the machine your talking about has a lot of torque in its spindle and some extra room for higher tool engagements, however in this process it will never have to use this extra power because I bet you used a HSM tool path...

 

Great stuff Ron, thanks for sharing...

[#Rekd™]

Well i can tell you this it was pegged over 85% spindle load for most of the 40 hours. Machine is a Italian machine with an 840D, HSK-63A that can run up to 27000k on the spindle. Those who have wore the hot chips down the back and necks standing 30 foot away can also tell you how it was cutting. You would think Aluminum would cool down after that far. Nope it doesn't. :scooter:

Those chips would be flying for sure!! Awesome stuff Ron!

[jlw™]

Video or it didn't happen.

[mkd]

Well i can tell you this it was pegged over 85% spindle load for most of the 40 hours. Machine is a Italian machine with an 840D, HSK-63A that can run up to 27000k on the spindle. Those who have wore the hot chips down the back and necks standing 30 foot away can also tell you how it was cutting. You would think Aluminum would cool down after that far. Nope it doesn't. :scooter:

totally obliterates my story of hitting the ceiling with chips on a boring mill with 8"face mill@1000rpm (max for the HBM). Couldn't have been more than a 25hp cut.

:notworthy:

 Really wish I had sombrero for the hot aluminum raining down.

[crazy^millman]

Video or it didn't happen.

 

ITRA and Stick NDA forbid Video.

 

 

totally obliterates my story of hitting the ceiling with chips on a boring mill with 8"face mill@1000rpm (max for the HBM). Couldn't have been more than a 25hp cut.

:notworthy:

 Really wish I had sombrero for the hot aluminum raining down.

 

They had to purchase Patio umbrellas for the operators for this machine. You could not stand next to the machine without them. The ISCAR rep had never seen anything like it in 20 years.

 

We were going against a shop with a claim of fame on their website with 100MMR on their machines. They had to send the part back not completed. Ben and Randall had a big part in this project and would have never got it done without their help and support.

[jlw™]

 

ITRA and Stick NDA forbid Video.

 

 

 

Excuses, excuses.  

 

Figured it'd be proprietary but it was worth asking.

[Watcher]

Ron,

 

How much warpage all this heat generates on the component compared to a more conventional set of speeds and feeds?

[crazy^millman]

Ron,

 

How much warpage all this heat generates on the component compared to a more conventional set of speeds and feeds?

 

Material was 98" diameter OD with 30in ID by 7" thick. It moved about .100. Part was done complete in 5 operation in a total of about 650 hours of machining. 2000 programmed operations between the 8 different Mastercam files. I am not even allowed to mention the company name we do this work for.

[BenK]

Video or it didn't happen.

 

Trust me, it was impressive. 

[Bob W.]

I have a boss that says that cnc machines can bore a .750 dia hole at 1100 ipm and hold tolerance of .0002.  Has anyone ever seen this before?

Tell the boss the machine couldn't even rough that fast.  To be able to even rough at that speed in that circle with a tiny end mill would require a machine with the ability to accelerate at 2.3G.  Most top quality machines can only do 1.0G acceleration.  If you were to cut this with a .25" diameter cutter at those specs you would need 3.5G.  Good luck with that.  This doesn't even account for the accuracy he is looking for.  Better get a boring head of jig bore for that.