Perhaps these would work for engraving since runout would be somewhat non-critical. However, with small milling cutters you want TIR of 0.0002 or so and there is no obvious way that the threads would achieve that level of concentricity. I find that it is hard to get low TIR even using precision ER collets.
> -----Original Message----- > From: Gene Heskett [mailto:ghesk...@shentel.net] > Sent: Thursday, April 18, 2019 6:30 PM > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] ER ATC tool idea > > On Thursday 18 April 2019 16:44:40 Roland Jollivet wrote: > > > Hi All > > > > The current discussion on making an ATC for ER collet style spindles > > has given me an idea. > > As Gene aptly says, R8 and ER collets weren't designed with ATC's in > > mind. > > > > In the application of routing, engraving and other light duty > > machining, the assembly of ER collet, nut and tool could be reduced to > > a simple screw-on tool holder. > > The collet itself would be dispensed with and the nut itself becomes a > > tool holder, with a Weldon style nose. Mostly it relies on the nut > > mating with the face of the spindle. > > > > I have attached two pictures(not to scale) showing how it might look, > > using a simple D bit, and where the second toolholder has a core that > > engages with the cone of the spindle for heavier duty tooling. > > A dozen of these could be machined by the user to take various tools. > > Obviously this design is to used on the Hackaday or similar ATC > > > > https://ibb.co/6vpFs97 > > https://ibb.co/dpwVLkB > > > > Thoughts?? > > Looks quite usable for engraving duties. But I'd be a bit spooky about > the setscrews long term grip, and would favor a dimple in the side of > the tool to foolproof it a bit. > > Cutting duties with 6mm end mills would still need a collets death grip I > think. YMMV of course. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > _______________________________________________ > 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
