On Mon, 2011-11-07 at 12:33 +0000, andy pugh wrote: > On 7 November 2011 02:26, Kirk Wallace <kwall...@wallacecompany.com> wrote: > > > I suppose a draw > > bar is going to be a problem. > > How does your current drawbar work? > I can imagine thet it might be possible to use the exisiting drawbar > actuator for the new spindle. Part of the solution might be to hold > the high-speed spindle in place with the 4 tapped holes in the face > rather than with the drawbar.
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. > There are laminations available with a decent-sized central hole that > would allow a through-bore motor to be made. > http://www.gobrushless.com/shop/index.php?app=ccp0&ns=prodshow&ref=SC+65mmstator > I think an ISO10 holder could be made to fit at least partly up inside > that, and you could probably still get at the face mounting bolts. > However I have not found a drawing which shows them. http://www.schaublin.ch/catalogues/PO039-042.pdf Usually outrunners are wound to get low RPM. I would most likely need as much speed as possible. Many of the laminations I have seen have odd numbers of poles so would not work. I do see the above stator has a number of poles that evenly divides by three, so would work if I wind six poles in a row. 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, hmmm. > An Inrunner might package more easily. > > Rather than a brushless motor, I wonder if gearing up the existing > spindle is an option. I have seen a centrifugal supercharger drive > which used friction drive to achieve a large speed increase using only > a slightly resilient outer drive ring, and slightly-floating-mounted > planets. These are almost ready-made for the planet job: > http://simplybearings.co.uk/shop/advanced_search_result.php?categories_id=4461&1_10=9205_1&21_210=-1&22_220=9205_22&23_230=9205_23&x=22&y=9&extra_field_filter=1 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. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ 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
