Actually that is along the lines of what I've asked. Some sort of brake that could limit the speed.
If you go back to steam engines the two weights swung out and shut off the pressure to the engine to keep it from running away. I'm not sure I could fit something like that in that space but I had an idea like that. Occasionally, until I solve that problem the socket goes flying off too. The square shaft of the wrench is hardened and I've used a Dremel to create a dimple but it's not deep enough yet. Adding a guard around the socket for safety is a good idea then. And if centrifugal force causes two arms with brake pads to fly out and run against the guard to slow it down that would work. But seems overly complex. Using that same guard idea but with pads that apply load to the socket to keep it from spinning away might be easier. If you think about the sound of an impact wrench it spins up and only when it hits a load do you get the hammering sound. I've been considering this as a solution instead. https://www.aliexpress.com/item/4000220757109.html John > -----Original Message----- > From: Roland Jollivet [mailto:roland.jolli...@gmail.com] > Sent: November-21-21 12:14 AM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] Closed loop control of air motors. > > It's not what you asked, but what about a centrifugal clutch/limiter? > Above say 200RPM it could swing outwards and lock, only releasing again > once the torque is removed. > > > > On Sun, 21 Nov 2021 at 09:45, John Dammeyer <jo...@autoartisans.com> wrote: > > > Has anyone ever tried any sort of closed loop control of an air motor > > similar the one on this butterfly impact wrench. > > https://www.penntoolco.com/52-424-9/ > > In order to not have both the TTS and R8 collet drop out of the spindle > > I'd like to be able to limit the number of turns to 2. > > > > What I've found however, is that 10mS pulses to the valve supplying air > > for CCW rotation barely move it until it's unloaded and then it immediately > > spins up very fast and does at least 4 to 8 turns. That's way too many. > > > > I've only got a one pulse per rev hall sensor detecting a magnet on the > > socket. But I suspect between reaction time of the valve, the > > compressibility of air and the rotary inertia of the motor that unless > > there is some sort of constant load that control is pretty well impossible. > > > > With servos, if the motor is loaded and then suddenly totally unloaded, it > > too might turn a number of revolutions before the control system could > > bring it back down to the original speed. > > > > Short of adding some sort of mechanical brake am I trying to do the > > impossible? Oh and to avoid another 1000 words to explain I've added a > > picture. > > John > > > > _______________________________________________ > > 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
