And therein lies the problem. For your NMBT-30 quick change tooling you could just as easily set up wave washers and just press and release the draw bar as is done on so many of those instead of turning into the holder itself. But it only requires one or two turns before that large cone is no longer held by friction.
Contrast that with .75" or so of the top of the R8 which is a sliding fit with supposedly 0.001" difference in diameter. That requires a substantial push to release it compared with the NMBT-30 or TTS that require a push of 0.050" or so. BTW, for fun I installed the 1/4" TTS held chuck and then manually brought the drawbar down with the air cyl. Then spun the spindle up to 700 RPM on the AXIS display. Some LCNC content here... 8-). The airmotor in the wrench, although not lubricated with oily air at this point, spun without any issues. However it was visibly clear that the draw bar nut wasn't completely centered as the bottom of the socket wobbled ever so slightly, and at the top there was also ticking noise from the 3/8" socket connection since it wasn't spinning concentric with the impact wrench spindle. Likely why the set screw works loose after a number of cycles. John > From: John Figie [mailto:zephyr9...@gmail.com] > Maybe I didn't fully answer your question. After the tool drops out. If the > button is held the impact driver will just keep spinning like an unloaded > impact wrench. > > John > > On Mon, Nov 22, 2021, 5:57 PM John Figie <zephyr9...@gmail.com> wrote: > > > When the load or unload button is pressed the impact driver first moves > > down and then starts impacting for as long as the button is pressed. I only > > let it impact for about 1 or 2 seconds. > > > > On Mon, Nov 22, 2021, 5:39 PM John Dammeyer <jo...@autoartisans.com> > > wrote: > > > >> So far I'm well under the $974 of the R8 version although if I had to pay > >> retail for the GIM controller I'm using then I'd be well over that. So far > >> I think I'm at about $200 Cdn. plus I'm using one of the first prototype > >> GIMs I build almost 10 years ago. > >> > >> https://www.kurtworkholding.com/product/kurt-bridgeport-series-i-std-2-j/ > >> > >> What happens with yours if you pressed the unload button for 5 seconds? > >> Obviously the tool would drop out. But does anything else unscrew or > >> require manual operations to put back? > >> > >> > >> > -----Original Message----- > >> > From: John Figie [mailto:zephyr9...@gmail.com] > >> > Sent: November-22-21 2:30 PM > >> > To: Enhanced Machine Controller (EMC) > >> > Subject: Re: [Emc-users] Spindle positioning. > >> > > >> > Instead of a drawbar with a hex end you could use the kind with a spline > >> > end like the ones that Kurt sells for their power drawbar. My Bridgeport > >> > came with a Kurt power drawbar. I have had it since around 2003. Still > >> > using the same drawbar. The socket looks kind of like a torx socket - > >> maybe > >> > it is - I never looked at it that close. The Kurt uses butterfly impact > >> > kind of like yours. It just uses regulated air pressure. I just let it > >> > drive the drawbar for about 1 or 2 seconds. It has never stripped and I > >> > have never replaced the drawbar. Tooling is NMTB 30. Home shop use > >> only. > >> > > >> > http://www.machineability.com/Bridgeport_series_II.html > >> > > >> > John > >> > > >> > > >> > On Mon, Nov 22, 2021, 3:39 PM John Dammeyer <jo...@autoartisans.com> > >> wrote: > >> > > >> > > Hi Mathew, > >> > > I want to be able to swap easily and quickly between R8 and TTS. > >> Here's a > >> > > selection of some of the tooling. > >> > > > >> > > http://www.autoartisans.com/mill/ToolSelection.jpg > >> > > > >> > > There's a full set of R8 collets of course. The spring loaded Tap > >> Holder > >> > > has a 3/4" shank so it really just needs a TTS collar to make it full > >> TTS. > >> > > The two gear cutter arbours for the different sized cutters. Face > >> mill. > >> > > Changing from a 1/4" drill bit means I have to swap out the TTS to > >> install > >> > > the R8 based expensive 16mm JT3 ball bearing chuck. > >> > > > >> > > To change completely over to TTS is expensive. To change to a mill > >> with a > >> > > NMBT or CAT cone type is really expensive. The lowest cost power > >> toolbar > >> > > system was the butterfly wrench and air cylinder. Cost escalated as > >> the > >> > > ordered electric pneumatic valves just never showed up from China so > >> I went > >> > > local. Not really expensive but it adds up as do all the fittings. > >> > > > >> > > At this point I could see spending as much as $150 Cdn. for the > >> planetary > >> > > gear and stepper combination. Still way less expensive than fully > >> > > switching over to TTS which I probably will over time but not all in > >> one > >> > > shot. And I'm not sure the TTS wouldn't slip with the 5/8" chuck > >> holding > >> > > a 1" reduced shank drill bit. > >> > > > >> > > First step now is to wait for the 12 point deep socket. > >> > > > >> > > John > >> > > > >> > > > >> > > > -----Original Message----- > >> > > > From: Matthew Herd [mailto:herd.m...@gmail.com] > >> > > > Sent: November-22-21 10:49 AM > >> > > > To: Enhanced Machine Controller (EMC) > >> > > > Subject: Re: [Emc-users] Spindle positioning. > >> > > > > >> > > > Hi John, > >> > > > > >> > > > You don?t need pull studs on the R-8 collets, just thread the draw > >> bar > >> > > into the collet. Either until it stops or loctite the draw bar at > >> > > > the right depth. Then use a Belleville washer and air cylinder setup > >> > > like Andy?s. > >> > > > > >> > > > Matt > >> > > > > >> > > > > On Nov 22, 2021, at 1:32 PM, John Dammeyer < > >> jo...@autoartisans.com> > >> > > wrote: > >> > > > > > >> > > > > ?It's the lowering of the wrench that I don't have a lot of > >> control > >> > > on. It's pushed down hard enough to keep the draw bar on top of > >> > > > the spindle so as it turns it pushes the sometimes a bit stiff R8 > >> all > >> > > the way down and out. If it's allow to move upwards (or I haven't > >> > > > locked the quill) then the drawbar may unthread but I then have to > >> push > >> > > on the draw bar. > >> > > > > > >> > > > > A sensor on the Z down may be what has to happen. Then repeated > >> tries > >> > > with blipping the air wrench until it goes down all the > >> > > > way is an option. > >> > > > > > >> > > > > Making a draw bar from oil hardening steel and hardening the head > >> a > >> > > bit so it doesn't get carved away and ends up more slippery > >> > > > might also be a requirement. > >> > > > > > >> > > > > John > >> > > > > > >> > > > > > >> > > > >> -----Original Message----- > >> > > > >> From: andy pugh [mailto:bodge...@gmail.com] > >> > > > >> Sent: November-22-21 5:41 AM > >> > > > >> To: Enhanced Machine Controller (EMC) > >> > > > >> Subject: Re: [Emc-users] Spindle positioning. > >> > > > >> > >> > > > >>> On Mon, 22 Nov 2021 at 08:03, John Dammeyer < > >> jo...@autoartisans.com> > >> > > wrote: > >> > > > >>> > >> > > > >>> One still has to line up the socket to the hex head of the > >> drawbar. > >> > > And since it can be at any position relative to the spindle the > >> > > > >> sensing has to happen against the hex head. Rotate spindle > >> until hex > >> > > head is at a known position. > >> > > > >> > >> > > > >> How about: > >> > > > >> > >> > > > >> Lower the wrench, but don't turn it on. > >> > > > >> Rotate the spindle until the wrench drops down to the "engaged" > >> height > >> > > > >> (sensor on the slide) > >> > > > >> Then operate the wrench. > >> > > > >> > >> > > > >> -- > >> > > > >> atp > >> > > > >> "A motorcycle is a bicycle with a pandemonium attachment and is > >> > > > >> designed for the especial use of mechanical geniuses, daredevils > >> and > >> > > > >> lunatics." > >> > > > >> ? George Fitch, Atlanta Constitution Newspaper, 1912 > >> > > > >> > >> > > > >> > >> > > > >> _______________________________________________ > >> > > > >> 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 > >> > > > > >> > > > > >> > > > _______________________________________________ > >> > > > 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 > >> > > > >> > > >> > _______________________________________________ > >> > 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 > >> > > > > _______________________________________________ > 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
