On 30 October 2012 06:26, Sebastian Kuzminsky <s...@highlab.com> wrote:
> Bone headed error... I am doing a small production run, using three > different drills, each mounted in its own tool holder. I had carefully > measured the length of each tool and recorded them all in the tool > table. I had run about 10 parts, everything was going great, just a few > left to go. > > Then I got distracted and loaded the wrong tool... Unlucky for me, the > tool I loaded was much longer than the tool the machine asked for, and > the machine happily drove a drill chuck with a #39 drill right into the > work. > > The drill shattered and disappeared in a spray of shrapnel (no one was > hit). The jaws of the drill chuck drilled about 0.100 inches down into > the work piece (soft aluminum, fortunately). The Z servo finally > signaled a following error and e-stopped the machine. The work and the > fixture plate absorbed all the damage, the table of the machine is still > unmarked. So it could have been worse. > > But the chuck is completely ruined. It used to be a pretty nice keyless > chuck, 1/32" to 1/2" gripping range, J6 taper. Now it's garbage: the > body (what I would normally turn to tighten and loosen the jaws) turns > very reluctantly, and the jaws don't move at all when i turn it... > > I got it off the J6 tool holder, and the J6 taper on the tool holder has > ~0.001 inches of runout now (measured with a DTI on the taper, while > mounted in the spindle and turning slowly). I don't know what the > runout was before the crash, and I don't know what's acceptable. Does > this seem reasonable, or should I scrap the tool holder too and look for > another? My spindle has a QC-30 taper, which is somewhat unusual - tool > holders like this can be hard to come by. > > In either case I need a new drill chuck. > > The wrecked chuck is of the keyless variety, and while that's convenient > I'm considering replacing it with a keyed chuck because they tend to be > shorter, and my quill is a bit limited in Z travel. Why do CNC machines > usually have keyless chucks? > > What do you all recommend for a good value on a drill chuck, about 1/32" > to 1/2", J6 taper? > > Keyed or keyless? > > Help me emc-users, you're my only hope! > > -- > Sebastian Kuzminsky > > > And old thread, but is your spindle like this? http://www.ebay.com/itm/BRIDGEPORT-CNC-EZ-TRAK-ERICKSON-QC30-30-TAPER-SPINDLE-/150283516254 If so, the taper should be the same as most '30' tapers, ie 7/24. If it is you should be able to adapt an ISO30 or BT30. Regards Roland ------------------------------------------------------------------------------ The Go Parallel Website, sponsored by Intel - in partnership with Geeknet, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials, tech docs, whitepapers, evaluation guides, and opinion stories. Check out the most recent posts - join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
