On 7 November 2011 17:58, Kirk Wallace <kwall...@wallacecompany.com> wrote:
> I have an electric draw bar like this one: > http://home.insightbb.com/~joevicar3/cheap_drawbar.htm > > It's not very subtle and would make short work of a 20 taper collet. Possibly not, if it was simply operating a bolt into the CAT40 adaptor, pushing-off a Belville stack. >> face mounting bolts. >> However I have not found a drawing which shows them. > > http://www.schaublin.ch/catalogues/PO039-042.pdf That does seem to be a good example of one of the many documents not showing the bolt holes, yes :-) According to my Machineries handbook, NMTB40 has two dogs in the face, and also 4 x 1/2" x 13 tapped holes. Mounting to those would allow you to poke alternative drawbar arrangements down the hole (and would preclude using the power-drawbar for fast loading and unloading the high speed spindle. > So let's see, 60 RPS = 3600 RPM. Common VFD's go up > to 400 Hz to give around 24,000 RPM. That would do nicely. This would be > a slam dunk if I didn't want the draw bar and went with ER collets, Can you use a VFD with a BLDC? I am pretty sure that Pete has run his BLDC drives in a 5k servo thread, which might get you 400Hz of commutation. > I found this: > http://www.tormach.com/product_pcnc_acc_speeder.html > > I suppose a smooth belt from the main spindle to an offset idler axle > then a belt back to an on-axis secondary spindle would work, but then > there would be no fancy high-tech electronics involved. I was imagining something similar, but cleverer. :-) -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
