On Tue, 19 May 2009 18:00:40 +0100, you wrote: >Just a quick followup on my query about using a single index pulse for >threading. I got it set up on my lathe with a magnet and a hall sensor. >It reads the speed pretty accurately though there is a bit of jitter at >higher speeds (500rpm upwards).
Hi Les - there's jitter here too using an encoder. Funny thing is I've a rpm meter on my screen and the jitter happens with the spindle stopped! It jumps to 100 rpm or so pretty randomly but frequently. It's being introduced from elsewhere inside emc or the pc it's NOT coming from the encoder, I've had the scope and a frequency counter on it and there's nothing there at rest. >On a few test threads the root of the thread comes out slightly wide if >I use lots of spring passes but apart from that it is pretty good, >certainly a hell of a lot better than I ever got out of Mach. I was >sometimes getting an unexpected realtime delay so I increased >BASE_PERIOD a bit. The threads then came out better though there was >still a small amount of variation between each pass. Overall I am pretty >happy though I will be using an encoder on my next machine. I'm not seeing any variation In practice and my threads are as good as I've ever seen my lathe produce. Steve Blackmore -- ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
