[j206]

Good day to you all, for the past 10 years the company I work for has been exclusively machining inconels and duplex stainless steels. We have recently had an RFQ for a large number of small aluminium components which are out of our comfort zone. However, we are eager to diversify so want to have a go at the parts and are willing to invest in the right machine tools.

The components are all suitable to mill rather than turn, quite small, less than 2" square and are all profiled internally with some quite small radii (1/8-3/16) and small 1/8 holes so high spindle speed is a must. I know from the research I have done so far that no matter how good the machine, a spindle running double shift at very high RPM can be a the weak link. I have even read that some companies keep spare spindles "on the shelf" to reduce down time when spindles fail.

Any recommendations or thoughts on good reliable high spindle speed machining centres are welcome.

Many Thanks.

[joeavaerage]

Hi,
from your description and the size tools you are talking about spindles in the region of 24000rpm are in order. If you are using 1/8th tools then 24000rpm represents 235m/min surface speed, which is pretty fair.
If you have a well sorted and tested toolpath, most likely with coolant you might like to up that to 30krpm or even higher.

I myself had a small German made 800W air-cooled spindle, and used it and used it and used it some more for ten years. Initially as a hobbyist but more recently as a business.
I would guess it has 5000hrs easy, and it was still working when I removed it.

More recently I bought a Dake (Chinese) 3.5kW(S1), 3.4NM(S1), 10krpm(rated) 40krpm(max) with an HSK32E tool interface. I absolutely love it.

It is true that spindles run long and hard do wear out....but I think you are overstating the risk. Unless you crash often I would expect thousands of hours from a spindle, even a Chinese one.

At the current time there are any number of Chinese manufacturers offering ATC spindles in the 3kW to 7kW class at 24000rpm, as cheap as I've ever seen them. I would not claim to be a fan of Chinese made
but I can say that they are OK, and for the price a damn sight better than OK. At the prices offered you could afford to have one on the shelf.

If you want to buy European or US made then be prepared to pay triple or more for similar specs as Chinese made. I have no doubt that it would be better, but three times better? No......I think that is a bit of a stretch.

My next spindle purchase is likely a Jager air cooled 6.5kW(S1), 6Nm(S1):

https://www.nakanishi-jaeger.com/en/chopper/11507001-01

I have priced this at 7.6k Euro for the bare spindle. I would really prefer this spindle, 18kW(S1),13Nm(S1), HSK63F/HSK50E tool interface and 80bar through spindle coolant, but now up to 23k Euro for the bare spindle:

https://www.nakanishi-jaeger.com/en/f-line/10408017

My business cannot really justify the expense of the later spindle, no matter how good it is. I need a spindle that can do 24000rpm day in, day out, but also want moderate torque that I can use the same spindle
in steel. For instance I use my current 3.4Nm spindle with 6mm and 8mm tools in steel at 5300rpm and 3980rpm respectively with reasonable torque authority. No doubt if you machine inconel then you have much better machines
than my modest homemade mill....but I do try to get the best possible use out of it which includes occasional steel and stainless.

The essential takeaway here is that once you go from Chinese made to European made you PAY bigtime! If you have a strong stomach price Swiss made Fischer spindles............probably the best on the planet.

Craig

[CncFlex]

Doosans with high speed Spindles are not bad for Alumunium and steel, New / not so old machines can give good results.

[basilemorani12]

Hey! Great to hear you're looking to diversify into aluminum work—especially with small, intricate components like the ones you described.

Please take a look at this guide on material properties of aluminum vs stainless steel. aluminum vs stainless steel


Brother Speedio (S500X1 / R650X2 series)
Extremely popular in high-speed aluminum work

27,000 RPM spindle options

Fastest tool change time in the industry

Great for lights-out production

Modular automation friendly

HAAS UMC-500SS or DT-2 with HSM options
More budget-friendly

15k–20k spindle options