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 <[email protected]> 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 > [email protected] > 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
