VF2SS running at 12k for hours at a time?

[SRT Mike]

I am looking at buying a new mill in the near future. I cut all aluminum and acrylic, and right now I am limited by a 6k spindle.

For the acrylic, I have a fixture with 40 parts at a time, egg shaped. Right now, it takes 3-4 hours for the final profiling pass.

I have heard from everyone that beyond 8k rpm, it's wise to have a spindle chiller. The Haas sales guy says I can run the VF2SS at 12k rpm all day long with no problems. I wonder if that's really true... so... is it?

I don't need the rapids or the fast tool change time, so I was also thinking maybe to get a standard VF2 with the 15k spindle, but again, can you really run 15k (or even 12k rpm on that one) for long periods without problems?

Any comments on the VF2 vs. the VF2SS? The VF2 with the 15k spindle would end up cheaper than the SS by a few thousand (I wouldn't be paying $10k for the sidemount 24-tool changer... It would be nice to have, but $10k more would push the cost of the VF2 beyond the SS price).

[haastec]

Yes you can run at 12K for extended periods.

The Haas uses a mixture of air and oil to help lubricate and cool the spindle while running. Also, there is a jacket of coolant (coolant running or not) that surrounds the spindle housing which also helps to dissapate the heat from the spindle.

Either machine, just make sure your tools are balanced properly per the machine specs and be sure to run a good warm up cycle for both machine and spindle.

[SRT Mike]

thank you haastec. Would you say the same about the 15k spindle option on the non-super speed VF2 - i.e. that you can run it for extended times, provided adequate warm-up time?


Also, on a different note (maybe I should start a separate thread), the probing system, does anyone use that for parts measurement? Can you take points and output the data in a format that could be read in something like Rhino as a point cloud? Or is it only useful for things like tool and offset measurement?

I realize you are dealing with machine accuracy when using the probe for measuring parts, but for me, even +/- 0.005" is more than adequate for measuring the parts I need to measure.

[Donkey Hotey]

We probably need to know more about your business model and what you intend to do with this machine. Do you need it to do everything (make tooling, be versatile enough to do occasional steel)? Are you doing high speed 3D contouring and that's why the cycle times are so high?

And the biggee: do you understand that above 10K you will absolutely need to balance all your tool setups? This is getting into shrink-fit tool holders and dynamic balancing. I also think the 15K spindle is based on ceramic bearings--as in "don't ever crash this spindle."

Needing a do-it-all machine, I've stuck to the 10K, 2-speed gearbox spindle on the two VF machines I've personally bought. It kept me right on the edge of needing to balance the holders and still gave me the versatility of low RPM torque. The SS model is probably a solid investment as long as you will never need lower RPM torque. You also say you don't need the side-mount tool changer but, the rapids are also faster on the SS. I think High Speed Machining is standard on the SS machines (check me on that though). That factors into whatever price you calculate.

Finally: have you considered the DT-1 instead or do you need the envelope of the VF-2? It's got smaller, lighter tooling and the table is startlingly fast. If you're doing a ton of 3D contouring on small parts, that might be your answer...or TWO of them in the same space as a single VF-2.

[Matt@RFR]

I just got done with a job of small brass parts, nearly 100% 3D surfacing and ran my '07 VF-2ss at 12k 10 hours a day for nearly a month straight. With the coolant running, the spindle never even got up to ambient temp. I run aluminum, brass and magnesium almost exclusively and all tools(except drills, etc.) 1" and smaller gets run at 12k. I warm my spindle up every morning, and I've not had any problems at all.

I also don't balance my tooling, but I do buy G2.5 tooling from Mari Tool. I understand just buying those tool holders does not give me a balanced tool as it runs in the machine, but again, I run 12k probably 95% of all my programs and have not had any issues.

Even though you're using high density fixtures, I would still get the SS. Making parts faster means more money, any way you cut it. I am thrilled with mine. And yeah, they don't have a whole lot of low end grunt, but even on steels, by using HSM toolpaths, it really doesn't matter.

The probes can measure parts. So far I haven't had a chance to get any deeper into it than just looking at the macro variable where the size/location/deviation numbers are stored after running a probing cycle, but it is possible to get the control to talk to a computer and make an excel spreadsheet on its own. You'll want to have a record of probe calibration before each run of parts though.

I am not sure, but I believe making a point cloud with these probes is possible, but it takes different software from Renishaw to do it.

[SRT Mike]

Originally Posted by Donkey Hotey We probably need to know more about your business model and what you intend to do with this machine. Do you need it to do everything (make tooling, be versatile enough to do occasional steel)? Are you doing high speed 3D contouring and that's why the cycle times are so high? And the biggee: do you understand that above 10K you will absolutely need to balance all your tool setups? This is getting into shrink-fit tool holders and dynamic balancing. I also think the 15K spindle is based on ceramic bearings--as in "don't ever crash this spindle." Needing a do-it-all machine, I've stuck to the 10K, 2-speed gearbox spindle on the two VF machines I've personally bought. It kept me right on the edge of needing to balance the holders and still gave me the versatility of low RPM torque. The SS model is probably a solid investment as long as you will never need lower RPM torque. You also say you don't need the side-mount tool changer but, the rapids are also faster on the SS. I think High Speed Machining is standard on the SS machines (check me on that though). That factors into whatever price you calculate. Finally: have you considered the DT-1 instead or do you need the envelope of the VF-2? It's got smaller, lighter tooling and the table is startlingly fast. If you're doing a ton of 3D contouring on small parts, that might be your answer...or TWO of them in the same space as a single VF-2.

Thanks for the reply - to answer your questions...

-The only steel or anything other than aluminum and acrylic that I machine is for the occasional fixture or for custom vise jaws (usually I make them from 303 stainless). In the last 7 years, I have cut maybe 4 or 5 pieces of 303 stainless, one piece of titanium, and a few pieces of brass.

-The cycle times are high because I have the 6k spindle, and I am doing 3D contouring of acrylic parts (think, like an egg shape cut in half lying on it's side - like a teardrop shape in acrylic). My fixtures are 6" x 12" and hold 15-30 of these parts. Ideally I would love to have 2 vises on the table and load 2 fixtures to make use of the 30" of X travel on a VF2SS

-I haven't ever crashed the spindle, but if the 15k spindle would be DOA from a crash, I'd stick with the 12k... because I am sure a 15k spindle ain't cheap And I make about 5,000 of those acrylic parts a year, but on the same machine I would want to make about 10 other parts in aluminum, which would be in runs of 50-100pcs at a time. I also develop 5 or 6 new parts a year, so I am doing several one-offs, so all it would take is a single mistake in my code to suffer a crash (hasn't happened yet though, knock on wood)

-I only have 4 toolchanges right now. I rough with a 3/4" square EM, rough again with a 1/2" ball EM, then profile with a 1/4" ball EM, then clean up the edges with a 1/8" square EM. So the toolchange time isn't a factor. My 20 tool carousel is full now though with cutters I use on other jobs, so having 4 extra slots would be nice since I have 2-3 tools where I change out drill bits and taps so I could load them all in and keep them in. But the 24 tools isn't critical, just nice to have.

-I don't think low end torque is really an issue... I rarely ever see much more than 20% load on the spindle now... the bottleneck is that at 6k RPM, my profiling is lots of little line segments. I drip feed my existing machine and if I try to move the feed rate higher than I do now (60ipm @ 6000rpm w/4FL 1/4" ball), the control isn't fast enough and it stutters and starves for data.


I think the HSM option would be a requirement. I also wanted to get ethernet since I have about 100 different NC files representing the front and back of the various parts I make (all use the same 4 tools) and each file is 1-2MB in size. It would be nice to just select the file off the network and go.

I have no experience with balanced tools... I have mostly Maritool endmill holders which say they are balanced to G2.5@20kRPM. I could certainly run the spindle at 10k if that's the upper limit, until we got shrink fit holders. Are shrink holders really needed at 12k RPM?

Thanks!

[SRT Mike]

Originally Posted by Matt@RFR I just got done with a job of small brass parts, nearly 100% 3D surfacing and ran my '07 VF-2ss at 12k 10 hours a day for nearly a month straight. With the coolant running, the spindle never even got up to ambient temp. I run aluminum, brass and magnesium almost exclusively and all tools(except drills, etc.) 1" and smaller gets run at 12k. I warm my spindle up every morning, and I've not had any problems at all. I also don't balance my tooling, but I do buy G2.5 tooling from Mari Tool. I understand just buying those tool holders does not give me a balanced tool as it runs in the machine, but again, I run 12k probably 95% of all my programs and have not had any issues. Even though you're using high density fixtures, I would still get the SS. Making parts faster means more money, any way you cut it. I am thrilled with mine. And yeah, they don't have a whole lot of low end grunt, but even on steels, by using HSM toolpaths, it really doesn't matter. The probes can measure parts. So far I haven't had a chance to get any deeper into it than just looking at the macro variable where the size/location/deviation numbers are stored after running a probing cycle, but it is possible to get the control to talk to a computer and make an excel spreadsheet on its own. You'll want to have a record of probe calibration before each run of parts though. I am not sure, but I believe making a point cloud with these probes is possible, but it takes different software from Renishaw to do it.

Sounds like you are doing exactly what I want to be doing. Glad to hear you are satisfied with the machine. Is there anything bad you would say about it? What other machines did you look at? The only 2 that are really on my radar are the Hardinge XR series and Doosan DNM. I've heard good and bad about both of those, as well as the SS.

I have fixed most of the issues myself with my current VMC (replaced encoder twice, did thrust bearings in X axis, etc), so I am not someone who be calling the HFO every time I see an error message... but one nice thing about my machine (Leadwell w/Mitsubishi control) is that there is a lot of documentation on the parts, and they are pretty standard off the shelf parts (like switches, bearings, etc). The HFO is about 2-3 hours drive from me, but I don't expect to need their help that often.

I have an Okuma lathe and I've had three different machines with different controls, never had a problem learning them, so I don't feel better off with Fanuc vs. Heidenhain vs. Haas vs OSP or anything like that - I am sure I can pick up the control pretty easily.

[Donkey Hotey]

Based on what you just posted, I'd take a look at TWO Minimills. As Geof has posted on here quite a few times, the only thing making you money is a spindle in contact with a part. If your parts are that small and in those quantities, having a large machine with a lot of parts isn't doing anything to relieve your throughput; it's only allowing more parts per cycle.

The Minimill would have a smaller table and I would imagine that axis accelerations are probably faster than a VF-2. Combined with the fact that you can just about fit two Minimills in the footprint of a single VF-2 and two spindles will produce twice as many parts and it's almost a no-brainer.

[gizmo_454]

Originally Posted by Donkey Hotey Based on what you just posted, I'd take a look at TWO Minimills. As Geof has posted on here quite a few times, the only thing making you money is a spindle in contact with a part. If your parts are that small and in those quantities, having a large machine with a lot of parts isn't doing anything to relieve your throughput; it's only allowing more parts per cycle. The Minimill would have a smaller table and I would imagine that axis accelerations are probably faster than a VF-2. Combined with the fact that you can just about fit two Minimills in the footprint of a single VF-2 and two spindles will produce twice as many parts and it's almost a no-brainer.

Not to mention if you got a hold of two Super Mini's with the 10K spindle. Now you are doing 3 to 3.5 times the work in just about the footprint of the VF2. Never the less, so far, we've had our VF2SS for almost two months now running nothing but aluminum on it so far. Running at 10K all day long and certainly no temp issues. The spindle is cold at the end of the day. I haven't had the guts to turn it up to 12K yet. ;p

Good luck with your decision!

Mike

[SRT Mike]

Originally Posted by Donkey Hotey Based on what you just posted, I'd take a look at TWO Minimills. As Geof has posted on here quite a few times, the only thing making you money is a spindle in contact with a part. If your parts are that small and in those quantities, having a large machine with a lot of parts isn't doing anything to relieve your throughput; it's only allowing more parts per cycle. The Minimill would have a smaller table and I would imagine that axis accelerations are probably faster than a VF-2. Combined with the fact that you can just about fit two Minimills in the footprint of a single VF-2 and two spindles will produce twice as many parts and it's almost a no-brainer.

Well, a 12k spindle on a machine that can contour using all that speed is going to dramatically increase my throughput over what I have now. A Super Minimill is $47k vs. $64k for the VF2SS... and I give up 2000rpm on the spindle, 14 tools in the changer, and 14" x 4" x 10" in X, Y and Z.

I would like to be able to load up the machine and walk away and let it run - just do more. I also want to be able to cut aluminum better than I do now. I am making these parts for my own products that I sell, not job-shop work, so the idea is a newer (more reliable) machine that will make all of our stuff quicker. I am getting by with a single 6k spindle machine now, so I don't think I need two higher speed machines, just one that's significantly faster than what I've got.

Appreciate the suggestion though, just not looking for a mini mill.

[Ydna]

Have you considered using upgrading to *virtually any machine* and simply running a spindle-speeder? (they can be either geared directly to the main spindle, or ran via pneumatics) you can then take advantage of a reasonably slow spindle if needed, and negate whatever speed it is since the actual RPM will come from another source.

I don't really suggest buying a machine and ostensibly not planning to use the spindle at all (lol) but if your money-maker parts really soar with high SFPM to the point where it's the main reason for adding a new machine, well a spindle speeder might make you happy. They cost a couple thou for a quality one.

IMO besides for that, I think you'd be happy with any machine that had 12K RPM or more. They will vary in work envelope size, and spindle torque (high and low) but you'll be able to do light work on steels with any of them, and they'd all be quite a jump from a 6k spindle for sure.

[Donkey Hotey]

Originally Posted by SRT Mike A Super Minimill is $47k vs. $64k for the VF2SS... and I give up 2000rpm on the spindle, 14 tools in the changer, and 14" x 4" x 10" in X, Y and Z.

I should have been more specific: Super Minimill2

It's 20x16 and the Z doesn't count (you're not using it for your parts so who cares?). That's really the same XY as a VF-1. You can get the same side-mount 24+1 toolchanger for it, it has all the similar features but has 833 IPM cutting feeds. You can also get an optional 15K spindle for it.

That machine could fill your production niche without taking up a lot of floorspace. If production needs grow beyond that machine, you can add a second one in the future. Not so easy with a machine as big as a VF-2.

Geof must be on another vacation somewhere or he'd be telling you how he makes pallets for offline loading/unloading. When a cycle ends, he opens the doors, blows off the pallet, loosens some fixture bolts and out comes the pallet. He drops another one inside, tightens it, closes the doors and starts the cycle again.

I'm NOT a fan of Minimills--any of them. I consider the travels and lack of spindle choices to be too limiting for somebody needing to do diverse work in it. It's just that in your particular type of application (long cycle-time, production machining of many small parts) it really seems to make the most sense.

I'll shut up now.