Agreed about making an encoder and I have an Omron unit with A/B/Z outputs "in the mail" from China.
The drawbar for my R8 spindle extends out the top of the spindle. It is a hollow shaft encoder with an 8mm through hole but that is insufficient to accommodate a drawbar. I suppose that I could couple it to the top of the drawbar with some sort of slip coupling but that has potential issues with alignment and coupling backlash. Perhaps I'm not looking at things the correctly but it seems that the simplest approach is using a pulley and belt to offset things. Also, the encoder is rated for a maximum of 10000 rpm and that is my max spindle speed; I could reduce with a 2:1 pulley + belt. Other suggestions are welcomed! -----Original Message----- From: Chris Albertson <albertson.ch...@gmail.com> Sent: April 1, 2022 11:37 PM To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] Homebuilt encoder It is hard to beat GT2. It is the current state of the art in belt-tooth profile. (except for the identical G3) But if you are using a belt, then just buy a $30 Omron encoder. No need to build one as it would be hard to make a better encoder. I doubt you could make an encoder as small and accurate as the Omron using normal CNC equipment. But if you could fit a pulley to the spindle, why can't you fit an encoder disk? On Fri, Apr 1, 2022 at 7:28 PM <ken.stra...@gmail.com> wrote: > There has been some good info on how to build an encoder on this thread. > My concern is how to couple an encoder to my mill spindle. Due to the > mill design it doesn't seem feasible to attach the encoder directly to > the spindle so I will need to use a belt drive. The spindle runs at up > to 10500 rpm. GT2 belts are readily available and the SDP-SI website > says that they can be used at up to 7500 feet per minute. I believe > that a 2-inch pulley spinning at 10000 rpm would move the belt at > about 5,200 fpm so somewhat below the maximum. Is there a better belt choice? > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ 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
