I would think it depends on how much of your milling is at high RPM.
The geared heads are pricey, but if you only need a few it might be a better option than splurging for a high RPM spindle and all the milling heads that can handle that speed. The high RPM milling heads are more expensive than the standard ones.
If you choose the high RPM turret and you don't buy the high RPM tooling, someone will absolutely fry a standard one by accident.
Currently, basically only time our live tools aren't running at max RPM currently is if they're tapping or not being used. Almost all our milling we'd run at least twice as fast as we could - it's nearly all aluminium or delrin at small diameters.
Doosan's SMX has a 12k milling spindle up top, 5k on the bottom. With that said, the normal turret arrangements all seem to be about 5k-6k for rotary tooling. With that said, spooling up lathe live tools to high speeds for extended periods can and will result in the rotary tools and drives wearing prematurely. Is this an extended run job?
It's not one job per se, it's a variety of around 70 parts, but as above, it's nearly everything we do.
emco has the bmt live head option from sauter that has direct 12k turret.
Thank you, will check that out.
there is always an option for an air spindle that can go 22K rpms but works with tiny end mills less then 1/8" most of the time.
I've heard of these, need to do some research - are you able to point me in the direction of reputable manufacturers?
Mazak has a high speed option for their turrets.
But what about just getting 2x speeders for you live tooling? A standard lathe with 6k can then do 10-12k.
It’s probably pricey but so are live tool holders rated for 10k
It's a possibility for sure, we'd just need quite a few of them (like 12 or so, some radial and some axial). If they're $5k a pop more than a standard live tools (just guessing here) that bumps the price up around $60k or so if we're grabbing 12 of them. Still seems like it could be good value compared to the $150-200k bump that a B axis adds though...?
I'd perhaps look into Index-Traub, and/or Citizen-Miyano machines. I know those firms specialize in production turning, so perhaps they'd have higher-speed live-tool options.
Also, Iscar makes their Spin-Jet coolant powered high-speed spindles. Perhaps that would be an option too?
I'll check out the Iscar spindles, thanks. I don't know much about Index beyond having seen their insane multi spindle things, but suspect they may be beyond our price point. We make around 70 different part numbers that we're looking to push to a new machine, each part usually in batches of 300-1000 parts per run. Generally we're tearing down setups 2-3x a week right now. I'd prefer that was 5x a week and we were smashing out entire batches of parts each day
(pipe dream at the moment!)
6K RPM on what amounts to a 2" pinion is already asking for trouble. These need to get rebuilt periodically anyway. Imagine the life span on 8 or 10K
That may well be the case, but our experience so far is a rebuild of live tool holders every ~3 years or so at a cost of about $1k/pc. For the differences I'm hearing of $150-200k between a twin turret BMT machine and a b-axis/lower turret machine it seems like we could rebuild a lot of live tools a lot of times before those costs caught up.
Mori NZX - 12,000 rpm rotary tooling from the factory. Some tooling manufacturers offer tools that will double the standard rpm on your machine.
Thanks, will check that out.
Index have 8000rpm on their C200 production turning machine. Still it might be a good option if you are looking to eek out the last seconds on a part. They have some awesome cycle times in their videos. If you're runnning only 1 or 2 parts it might be worth it to get them to test cut the part and make the program.
Thanks, I'll check the C200 out.
They work pretty great. The live block rebuilds will be you up if you run them at max RPM all the time.
That sounds like something we may just have to deal with.
Straight radial live tools designed for 10-12K RPM have the obvious advantage of not having any gears at all, and will go a lot longer before requiring a rebuild than a 2:1 speeder.
Hard to go wrong with the NZX.
Thanks for the input. Most of what we do is face milling, not so much radial tooling unfortunately, so I don't see a way of getting around some kind of gearing, but that is a fair point in favour of a proper 12k or 20k head too.
Em .. there is a reason.
Why don´t small spindles, short, of high rpm, abound on the market ?
Like those needed for the application.
Because they won´t last.
I refused a quote for about 500.000€ for live tools for similar reasons.
It was all in spec, guaranteed, from the manufacturer and the tooling manufacturer.
But we chose (HAAS Espana HFO, Spain) to no-quote because we had experience the radial tools would not last and would not continue performing to spec.
The customer was upset.
I told him, personally, ..
"listen I can fix any mechanical error we make.. but I will not put us in an error I cannot fix."
Owners:
Does not matter what he tells You..
It would be vastly worse if we sold stuff to him and then it did not work as he expected.
I'm not saying there isn't a reason it's not widespread - if everything was easy, every machine would have a billion horsepower and a trillion RPM and nothing would ever wear out or break (and it'd run 168hrs a week, top up its own coolant, be fully automated etc etc). What I'm trying to find out is not "all the times someone else knew something else was a bad idea" but whether such a solution exists in a way that a reputable manufacturer has deemed it sufficiently reliable to bring to market. Yeah, there's possibilities for things to go wrong there, but I'm not looking for perfection, just better-than-we-currently-have.
