A key advantage of the shrink-fit toolholder is that the clamping part is much smaller than anything else. These holders are often specialized for accessing deep pockets.
> On Nov 10, 2022, at 6:31 AM, Stuart Stevenson <stus...@gmail.com> wrote: > > Gentlemen, > I walked into a booth at IMTS a few cycles ago. This booth was a cutter > manufacturer touting the shrink fit tooling and heat shrink machine they > manufacture. All the propaganda focused on how the shrink fit process holds > the tool better than any other method. As I was looking at the line of > cutters in the display I saw an end mill with a spiral groove on the end of > the shank portion. I asked what that was for. I was told this was developed > to prevent the cutter from being pulled out of the adapter during high > speed cutting. It also prevented cutter spin in the adapter. > I have never owned or tried shrink fit tooling. > I have wasted my money on the so-called "hydraulic" collet holders. The > holders' performance was an absolute joke. > The ONLY non spinning/pullout end mill holder(adapter) I have seen is a > mechanical (ie weldon) style. > I will say my high speed experience is limited to a 14,000 rpm 50 taper > spindle but if the cutter manufacturer had to develop a mechanical slot to > prevent spinning/pullout maybe the focus to prevent spinning/pullout should > be mechanical even at the bridgeport level. > Just sayin > HTH > Stuart > > > On Thu, Nov 10, 2022 at 2:34 AM gene heskett <ghesk...@shentel.net> wrote: > >> On 11/10/22 02:48, John Dammeyer wrote: >>> >>>> From: gene heskett [mailto:ghesk...@shentel.net] >>>> It works well John, on the go704. I'd like to come up with a qcth holder >>>> for them on the Sheldon as it has the torque to drive much bigger taps >>>> but haven't quite figured out how to make such a critter, plus the >>>> sheldon has no gibs to constrain the carriage from being lifted clear of >>>> the ways when huge gobs of the torque reaction comes into play. I'd need >>>> to hang another 30 lbs on the back end of the crossfeed to contain that >>>> for say a 3" tap. That in any event even though I have the tap that big, >>>> is a g76 job. But at a 3" size, I'd be longer shaping the boring tool >>>> that doing it, my CBN wheels are quite fine, 2500 grit but fine is also >>>> slow, fragile and expensive. >>> >>> Hi Gene, >>> I'm mostly using the TTS holders and some of my more expensive tooling >> is still R8 so I'm not converting over completely. >>> >>> I'm thinking that your approach with 4 set screws to hold the tap might >> work well with TTS holders. A custom holder with a hole for the tap shank >> and 4 set screws keeps the tap from turning. >>> >>> Now we're back to the original question I posed. If this TTS holder >> with a 3/4" shank into the custom R8 holder with say 20 ft-lbs torque on >> the drawbar won't turn then it's fine for tapping up to the tap size. >> Since the TTS come with at least 1/2" holes it makes for a reasonably large >> tap. Up to 7/8" shank which is once again listed as the limit for R8. >>> >>> And it makes the tap holders a lot less expensive than using ER20 >> collets which are only good up to a certain size. Purchase a TTS for 1/4" >> shaft, mount in a lathe collet and bore to the size of the target tap. >> Drill the 4 holes and tap them. Now it's a TTS Tap holder. >> >> And I'm having a hard time visualizing that, can you scribble up >> something and put it on your web site? >> >>> If one wanted to modify the spindle it would be possible to put a pin >> hole just outside the diameter of the TTS tool. Then modify the TTS tap >> holder to have a flange like the pin on your holder that goes into the >> collet. >>> >>> In fact, modify all the TTS holders to have the flange and it's possible >> to prevent all TTS tools from spinning in the R8 holders. Not only that >> but the M66 command can put the pin in the same place so installing TTS >> indexed tools becomes trivial. >> >> The word flange is confusing me unless its used to establish a constant >> length to put in the tool table as TLO. And that would still be subject >> to error from inconsistent tightening of the drawbar. >> >> My next mechanical thing on the go704 will be stripping a 1/4 ratcheting >> screwdriver motor out, and rigging it on old 3d printer screws to >> reengage/disengage from the drawbar, It has the torque I think, to break >> the drawbar or strip its threads in left to hammer the bar for more than >> 1 or 2 seconds. Then rig M6 to run it for tool changing, possibly from >> mid gcode file. I use the drywall screw driver to do that now but need >> more hands, one to run the driver, one to hold the spindle still, and >> one to catch the tool when it comes free. By my count that's three >> hands. :o) Needs more thought... >>> >>> John >>> >>> >>> >>> >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> . >> >> 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, 1940) >> If we desire respect for the law, we must first make the law respectable. >> - Louis D. Brandeis >> Genes Web page <http://geneslinuxbox.net:6309/> >> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > > -- > Addressee is the intended audience. > If you are not the addressee then my consent is not given for you to read > this email furthermore it is my wish you would close this without saving or > reading, and cease and desist from saving or opening my private > correspondence. > Thank you for honoring my wish. > > _______________________________________________ > 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
