I don't know if you've seen my attached picture before but it shows the signals during a complete turn of the turret (slightly more than a turn to be honest). The TOOL CMD shows the period of when the 24V are applied to the DC motor that drives the turret forward, about 3.3 seconds in time. The total tool change time is about 4.9 seconds including locking. The STROBE is the pocket sensor which sort of indicates the border between the pockets. To shift to the next tool pocket it's therefore not sufficient to back off when that signal is reached the first time. As can be seen from the recording using the stock hardware one must continue past the first trigger, continuing until the next one before backing off. I might switch to better hardware eventually but spontaneously it feels like this can be solved in software - hopefully. :-)
Regarding your tool changer I've understood that a ratcheting screwdriver is a good solution for that. If it works it doesn't matter it if makes some noise. [image: Turn_50_Turrret.PNG] Den fre 8 jan. 2021 kl 18:32 skrev Gene Heskett <ghesk...@shentel.net>: > On Friday 08 January 2021 11:06:00 Andreas Linnarsson wrote: > > > It will increase by "1" after every (unsuccessful) completion of a fwd > > jog. After position 6 it will wrap around to 1, even though the index > > position isn't sensed. I understand if index isn't used after homing > > though. > > > > Do you know anyone who has used the carousel comp with this kind tool > > turret? Or am I the first? If they've made it work I'm quite curious > > about what their encoder wheel looked like or how they did it. I've > > 3D-printed a variety of designs in search for a pattern that the > > carousel comp would be compatible with but I cannot really get my head > > around if another design would be the solution. I haven't found > > anything that works so far and logically I can't see how it would work > > to stop on the first pocket trigger. Not since that will always be the > > same as the last one due to the reverse locking. > > > > Regards, > > > > Andreas > > Can you describe your signal generation as it turns? > > It seems to me that your next pulse s/b derived not from the carousel > position, but from the locking pawl as it falls off a tooth and it then > backs up against the new tooth it just fell off of to initiate the lock. > > And that the falling pawl generates a pulse to initiate the reversal > itself. So you get one and only one edge pulse as it falls. And one > might detect the locked rotor amps of the motor being stopped by the > pawl to both turn off the motor, and tell linuxcnc that a lock in the > new position has been achieved. > > I would also if switching the motor with a relay, would use 2, wired so > the when off, the motor armature is shorted, so the sequence would be, > see the pawl fall, turn off the motor fwd relay so its back side > contacts short the motor, stopping it fairly rapidly but gently, then > enable the reverse relay maybe 100 milliseconds later. Lots easier on > things too. Particularly the psu running the motor. There is also, for > about 7 dollars US a BTS 7960 half bridge based board with 2 of those > with a 27 volt rating that can switch 43 amps that does essentially the > same thing as the relays and a bunch cheaper. I am controlling a 100 > watt 24 volt motor to drive a BS-1 indexing head from linuxcnc. No > heating even when my pid is miss set and its oscillating violently. I've > a 450 watt 24 volt supply its crowbarred and turned off for a 3 minute > cooldown, but no detectable heat from this board. Phenomenal little 2" > square board for 7 bucks. Driving it both directions with a pwmgen in > mode 2. > > But I don't have such a tool changer critter myself, so I'm just > guessing. My holdup is figuring out how to bold the spindle and drop a > ratcheting impact tool onto the drawbar and run it, its an R8 spindle. > And the end wrench supplied does not exert enough force to adequately > hold the tool. So the ratcheting screwdriver is needed. > > > Den fre 8 jan. 2021 kl 15:02 skrev andy pugh <bodge...@gmail.com>: > > > On Fri, 8 Jan 2021 at 13:27, Andreas Linnarsson > > > > > > <andreas.linnars...@gmail.com> wrote: > > > > Did I miss(do) anything? > > > > > > I don't think so. > > > > > > Can you look at the current-position HAL pin to see if it decreases > > > by 1 at the end of the reverse pulse? > > > > > > -- > > > 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 > > > 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) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > 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 >
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