ER8 collets go down to 0.039" but that only makes it down to #61 drill... darn it. I do have one of those pin vise things that mount in a collet and will hold a #80 bit but it is a cheap one. Are you drilling by hand with the #72 bit?
John On 10/30/2012 9:12 AM, Gene Heskett wrote: > On Tuesday 30 October 2012 09:50:06 John Thornton did opine: > >> Another reason is collet holders are much shorter than a drill chuck and >> on Z challenged machines like my BP switching between an end mill holder >> an a drill chuck is not always a practical thing... but at $200 for a >> set of collets it will be out of the range of many home shop machinists. >> I do have a jacobs chuck for my BP but don't use it. >> >> John >> > I have similar problems with my little toy mill. The average, I can buy it > at Lowes, replacement chuck cannot reliably mount or hold the drills I use > which can go as small as #72's. If I ever seriously damage the chinese > Horse brand chuck that came with the mill, I'll be out of business for > drills under 1/16". And its runout leaves a lot to be desired & getting > worse. I have to creep up on starting the hole and give it time to self- > center, if it will, depends on the work material. copper plated pcb's are > usually ok, TSC's grade of steel rod for a BP nipple gets very very pickity > & needs wholesale qty's of the chosen bit size because that dulls them > rapidly. And I've not found anyone who will sell me carbide #68's in ten > packs w/o a 3 digit price yet. :( > > For this sort of work, I seriously need an old 1/4" chuck from a 50 yo > electric hand drill, but it still drills holes & I hate to tear up > something that actually still works after all this time. :) > >> On 10/30/2012 7:31 AM, Erik Christiansen wrote: >>> On 30.10.12 06:15, John Thornton wrote: >>>> I don't use a drill chuck on any of my mills, I've been told ER >>>> collets are much better and that is what I use. >>> Can't disagree a lot, for milling, anyway. IIRC, it was in a Tormach >>> document that I read a note similar to this: >>> >>> Drill Chucks: >>> Using a drill chuck to hold a tool used for side cutting is >>> dangerous, though educational and often expensive. A Jacobs taper >>> is _not_ designed for lateral loads, so vibration and side loads >>> generally shake the drill chuck off its mount. As the spinning >>> mass dissipates its kinetic energy, the flailing cutting edges >>> shred any flesh or other vulnerable material in its path. Drill >>> chucks are only to be used with axial forces, i.e. drilling. >>> >>> It's now one of my MOTD entries, so once in a while my wetware RAM is >>> refreshed. >>> >>> I'd hate to buy a collet for every drill size I might use. > Amen on that! Not to mention that for my #2 morse spindle, collets under > 1/8" suddenly are made from unobtainium. > >>> Erik >> ------------------------------------------------------------------------ >> ------ Everyone hates slow websites. So do we. >> Make your web apps faster with AppDynamics >> Download AppDynamics Lite for free today: >> http://p.sf.net/sfu/appdyn_sfd2d_oct >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users > > Cheers, Gene ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
