On Mon, 30 Jan 2012, Viesturs L?cis wrote: > Date: Mon, 30 Jan 2012 22:33:57 +0200 > From: "[UTF-8] Viesturs L?cis" <viesturs.la...@gmail.com> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] US Digital encoders? > > 2012/1/30 Peter C. Wallace <p...@mesanet.com>: >> >> Before you change encoders, and noting that others have used the CUI/AMT >> encoders with success, can you try a little experiment to make sure this is >> not a noise --> losing count/commutation issue? > > Thank You for the explanation! I really appreciate that! And this kind of test > with marking a spot on motor's pulley and frame is neat! > Unfortunately I left yesterday after spending 4 days at client's site. > And it is several hours to drive there. > So I do not have access to machine and it would be way too expensive > just to go there and test it. And there is nobody whom I could ask to > do it for me :( > > I do agree that I should gather as much information as possible, > before making any decisions, but I find the associated cost to be too > high. > > I have flexible CAT5 cable with shielding used for encoder and hall > sensor signals, shield is connected to GND only in the PC end, so I do > not think that it could pick up some noise in the cable. > I used a superglue to eliminate any chance of slip between motor shaft > and encoder wheel. > Jon Elson did very good comparison and analysis on these encoders and > their poor performance. > It is not only machine for my own use, but I also have to provide 2 > year warranty, so I do not want to risk of getting encoders working > now and then solving this issue again in few months or so. > > Based on these points I think that I have enough grounding to change > the encoders, although that also is adding extra cost. > > I have no doubts that there are users who are happy with their CUI > encoders. But there are also many cases, when CUI has let their > customers down. Unfortunately I have heard opinions only from that > second group. > > Viesturs
I am suggesting this test because if there is a noise problem, different encoders may not help. A possible noise source is the PWM signals. This can couple into the encoder if the motor frame ground is not returned to system ground > > ------------------------------------------------------------------------------ > Try before you buy = See our experts in action! > The most comprehensive online learning library for Microsoft developers > is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, > Metro Style Apps, more. Free future releases when you subscribe now! > http://p.sf.net/sfu/learndevnow-dev2 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
