Yes, a cute design. However, unless I missed it, he doesn't address determining the varying stickout of the cutter. After every tool change you would have to move the spindle to over a height setter and then to the cutting position. A lot of time plus table real estate used for the tool changer plus the height setter.
> -----Original Message----- > From: Gene Heskett [mailto:ghesk...@shentel.net] > Sent: Thursday, January 10, 2019 5:24 PM > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] tool changer with swiveling arm > > On Thursday 10 January 2019 14:18:46 Martin Dobbins wrote: > > > https://hackaday.com/2016/06/20/hackaday-prize-entry-diy-automatic-too > >l-changer/ > > > > ?? > > > > Martin > > > Now that cute and makes use of the leverage nicely. But I do not see it > actually change from the nut in, all I see is from one tool of x size > shank to another tool with the same size shank. IOW, the collet is not > being changed. But I don't see a good reason why the spindle motor > couldn't be used to unscrew the nut and leave it behind along with the > collet and tool, then taking the spindle to a position above another > nut, collet and tool with a different sized shank. Its idea could likely > be expanded to 6 or even 8 tools. > > A clock spring could be used to put the lazy susan back to its index > position, and have a lookup table that would then tell the gantry where > the next tool lives. Drop the spindle into that gatersocket, spin the > spindle until its semi snug, and drive the suzan to finish the > tightening. Humm, small motor to preposition the empty socket in the > wound up position would be even better, the drive the gantry to loosen > it and turn the motor backwards to complete the unload. Reverse to > load. > > I like it. But how does he position the motor so the wrench just slides > in? Or is it under power, say at 5 hz to do that. > > Most of these motors haven't an encoder to facilitate the alignment. > > Most of what I might do could be handled with 3 tools at the ready in a 4 > station wheel and one in the spindle for starters. If more tools are > needed it looks super easy to exchange all 3 in the wheel. This puts the > onus to remember what you are doing on the operator, but this is what we > have (msg,text to print) for. > > > ________________________________ > > From: Gene Heskett <ghesk...@shentel.net> > > Sent: Thursday, January 10, 2019 12:43 PM > > To: emc-users@lists.sourceforge.net > > Subject: Re: [Emc-users] tool changer with swiveling arm > > > > On Monday 07 January 2019 05:22:53 andy pugh wrote: > > > On Mon, 7 Jan 2019 at 05:07, Gregg Eshelman via Emc-users > > > > > > <emc-users@lists.sourceforge.net> wrote: > > > > I've seen some that have each tool holder coded and read the > > > > holders in the chain or carousel as it moves. > > > > > > In fact the machine in the first post is just such a machine. The > > > tool holders all have a mechanical bar-code made of a stack of rings > > > of different diameters on the outside of the tool holder body. > > > > I have spent some time daydreaming about a tool changer that changes > > the whole ER-11 for use with this gantry mill. Something that changes > > the nut, collet and tool all in one swell foop. \ > > > > Obviously one would have to motorize with enough force to adequately > > tighten and loosen the nut, but spinning the nut on and off with a > > short burst of the spindle motor. > > > > Where I hit the rude awakening is in positioning the two wrenches > > independently, in order to exert enough force to get an adequate grip > > on the tool. I can visualize tickling the motor till the top wrench > > snaps onto the spindle double d flats but then possibky pushing the > > top wrench into engagement key/spline. The nut wrench has to be > > articulated so it snaps into place later. That would be helped if it > > was a 12 point socket. But then we may need 2 or 4x the torque to > > loosen it as it took to tighten it. And because the tool may slip in > > and out of the collet while the nut is loose, some means of driving > > the tool back into the collet to a fixed projection, then some > > additional time to measure the stickout sure seems like a good idea. > > > > That may yet make me learn a cad program. Fugly thought, that. > > > > Cheers, Gene Heskett > > -- > > > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > Cheers, Gene Heskett > -- > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
