Haas VF3 feedrate ?

We are looking into purchasing a Haas VF3YT. The specs say that the max feedrate is 650 ipm. We do a lot of 3d machining and was wondering what is the max feedrate the machine will do and still hold its accuracies. We have a GR 408 and the max feed is spec'ed at 1000 ipm. Our actual is 220 ipm when doing 3d work. I would really like someone who actually does 3d work to respond as we have to cost justify to the big wigs and I would like a "true" number to use. Any input would be greatly appreciated.

Put the onus on the HFO to demonstrate the machine. Give them a sample part and have them proove to you how fast the machine can do it and still hold the numbers. You stand there while they run it off and then inspect it.

If you are looking for a hardcore surfacing machine, I hate to say it, but the haas does not cut the mustard on this one. I the acceleration and deceleration on any "low end" machine is set so high, the ballscrews are not tight enough to handle, etc etc.... It will do it once and a while with no problems, but honestly if you are doing moldwork and other tight tolerance, high feedrate parts on the daily, I would consider a higher end machine. I personally would reccomend a OKUMA. I know that people will contend, but I think that mazak is junk, too. Don't get me wrong, I run haas every day and actually enjoy it, but it's in a R&D setting, not too demanding as far as all day all night precision....It's hard to say what your actual feedrate would be without seeing your toolpaths. With a lot of radical direction changes, dont expect to get over 200IPM.

Thanks

Thanks guys for the replies. I spoke with a Haas programming tech and he said that with what we are doing (I sent him some tool paths), we should be able to run 350 to 400 ipm. We are an R&D shop working for a corp. Our tolerances for our type of work is +/- .002 (a mile for machine work). Sorry for not posting better info. Again thanks for the input.
GC