I thought that if 100 detents and 1tick/detent was all that was needed, then it would be simple to make. 400 ticks/rev is still do-able, but anything above that means a purchased encoder, and then the incentive is lost.
I think the detent is invaluable where any overshoot will crash the tool. On 1 March 2017 at 18:31, Chris Albertson <albertson.ch...@gmail.com> wrote: > I think when you design one of these you have freedom to define the > mechanical detents per revolution and the number of encoder "ticks" per > revolution independently. You are arguing for these numbers to always be > the same. But why? Why not 10 ticks per detent? I think with a jog > wheel the higher the ratio the better. Four is better than one. On the > one to one case it is likely the machine (milling table) will jump in steps > as fast as the motors can move then stop at each detent. In the 10 to one > case the table would move only as fast as you turn the dial between > detents. > > I'm wondering why there are detents. I don't see much reason for having > "clicks" in the wheel. My preference would be to design the wheel using > "damping grease" so I'd have a wheel then turns smoothly with bit of > friction that stays put when you release it. And to have the encoder be as > fine as possible, Maybe even optical with 4096 "ticks" per revolution so it > would have an analog feel. In this case that ratio would be 4096/0 or > infinity ticks per detent. MUCH higher then four or ten. > > > > On Wed, Mar 1, 2017 at 4:42 AM, Roland Jollivet <roland.jolli...@gmail.com > > > wrote: > > > I had always assumed that machine MPG's generated one state change per > > click, but following Gene's discussion, I pulled out my 1988 Fanuc MPG, > and > > saw that it was also 4-states per click. Obviously, one 'pulse'/detent > > > > Does anyone know the rationale behind this? > > I assumed one always wants one step per click, so why not use a 25ppr > > encoder and use every change? > > Used as currently is, it would have to be a software /4 to be useful. You > > could also do a /2 or /1, but no-one ever wants a x2 or x4 on their MPG > > It's always x10, x100 or whatever, so the count/detent would always have > to > > be n/4 x 1 .. or.. n/4 x10 in software. > > > > Alternatively, if I was going to make my own MPG, surely I would just > make > > a 25ppr encoder and make it 1 detent/change? > > It's far easier for me to make, so surely it would have been for Fanuc > too? > > > > What am I missing? > > > > Regards > > Roland > > ------------------------------------------------------------ > > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > -- > > Chris Albertson > Redondo Beach, California > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
