When I first got the mill I rebuilt everything on the vari-speed drive and the spindle with the best bearings and parts I could find. Then a couple of years later I rebuilt the vari-speed drive again. I really don't want the vari-speed drive. My buddy had one of his BP's converted to timing belt VFD drive and it is very quiet running.
I can go as high as 3hp with the GS2 drive I have now. Above that and I would have to run off of my RPC and VFD's don't like that option. An extra $100 for a 3hp motor is not a problem but the max RPM for the 3hp drops down to 4000 from 5400 on the 2hp. The constant hp RPM is pretty much the same at 2600 for both motors. I'm thinking that at higher spindle speeds your doing tiny stuff so hp is not an issue. Just to revisit a bit if I go with the E2007 Marathon XRI series inverter duty motor and have a small gear reduction of 1.25:1 my max spindle RPM is 4320 and the min is 140 RPM. This seems like a nice RPM range to have. I normally tap at 250-300 RPM so at this gear ratio the motor would be running 312-375 RPM. I think the conversion is straight forward although it has been a couple of years since I've been inside the BP head. Here is a video of the BP tapping some blind holes that I took the other day. http://www.youtube.com/watch?v=vC5B_l5HuQQ One thought I need to keep in mind is this is a knee mill and the ways are not perfect but it has become more useful to me since I've added the encoder to the spindle which means I use it more. It is within arms reach of my desk and I wear ear plugs when I run it for long periods of time so silence is golden to me. Oh on the subject of steppers for this machine I have one on my rotary table and have not figured out where to hook it up yet... I have a 5i25 7i77 in a tiny computer with only one PCI slot and no parallel port. Thanks for all the input. JT On 8/23/2013 8:46 PM, Gregg Eshelman wrote: > On Fri, 8/23/13, Greg Bentzinger <[email protected]> wrote: > > Subject: Re: [Emc-users] BP Knee Mill Spindle > To: [email protected] > Date: Friday, August 23, 2013, 7:30 PM > > John; > > BP was pushing the edge with the 4200 rpm top speed. When > you look up bearing specs most consider 4000 rpm max > continuous under load. If your head is truely that noisy > then something else isn't right - cutting air that machine > should just purr with the loudest noise being the motors > fan. > > ------------------- > Consider an upgrade to ABEC 7 grade bearings if you are going to run at > higher speeds all the time, eh? > > ------------------------------------------------------------------------------ > Introducing Performance Central, a new site from SourceForge and > AppDynamics. Performance Central is your source for news, insights, > analysis and resources for efficient Application Performance Management. > Visit us today! > http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Introducing Performance Central, a new site from SourceForge and AppDynamics. Performance Central is your source for news, insights, analysis and resources for efficient Application Performance Management. Visit us today! http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
