On 25 March 2014 02:49, Gregg Eshelman <g_ala...@yahoo.com> wrote: rig isn't going to cut it. > > I've been thinking on how to build a tool changer for NMTB, without > having to add a spindle encoder and fine motor control. Since the > spindle has two drive lugs, probably an alignment jig that pinches from > the sides on those blocks then something (solenoid or air cylinder) to > hold the spindle brake.
Here is a thought that I have had. You could have a small carousel of tools mounted on the end of the bed, so that at least two tool locations were within reach of the spindle. The carousel is unpowered, but has spring détentes. It can float vertically by a small amount. To pick up a tool the spindle plonks itself down on top of a tool, and rotates slowly, pushing down the carousel if the lugs are not aligned. When the lugs are aligned the carousel pops up, and triggers a switch. It is then safe to clamp the tool, and either lift the head (for a simple bucket-style carousel) or slide it out sideways. To change the tool the spindle puts the in-spindle tool into the empty slot, then coordinated movements of the table are used to rotate the carousel to place the required tool within reach of the spindle. It might be necessary to load some tools that are not actually wanted if the tool ordering is non-optimal. This is something of a hybrid between a rack changer and a carousel. The (only) advantage over a rack is that it takes up less space on the table. It could work with quite a large tool chain, for example. It doesn't necessarily have to be the spindle that moves the chain/carousel. there could be a pawl arrangement at the far corner of table movement. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
