I just wired up a touch probe last weekend for the first time. It was pretty easy. No special wiring, I simply wired a gator clip to one of the inputs on the parallel port (but if I touch the probe to a bad spot itll fry the input so an opto-isolator is inevitable.). My whole machine is connected to ground (via the spindle controller) so clipping the gator clip to my metal workpiece is enough to set depth. To test, I outputted a point cloud log and imported into solidworks, it created a virtual version of my bent plate with a coin on it.
My goal, however, is to use it to set tool height and to create corrective point clouds for engraving and pcb milling. Setting up emc2 for the probe is childs play. Just rerun stepconf wizard and specify the probe port and recommend using the input in inverted mode (probe active when wire connected to ground). [Advanced] I had custom hal mods, so I running stepconf is not an option for me. If you have custom mods like a joystick pendant email me and I can send you the two lines. These lines go in your <configname>.hal. [/Advanced] Once you have your new config generated, load emc and go to "Machine | Hal Meter" menu. Choose the signals tab and find the "probe" signal and select it. You will see the other meter window show the TRUE/FALSE state of the probe signal. If touching ground toggles the state you are set. Whether you are configured normal or inverted signal, the probe signal should say TRUE when the probe is active. If it's backwards, go back to config and invert the port. Now you can test the G38.2-6 commands. Easy to use, they feed using the feed rate until the probe is TRUE or if desired until the probe is FALSE. Emc variables are also set to the XYZ location when probe was toggled so you can read them, compute based on them, or log them to a file. Important: When the probe is detected, the Z axis still has to obey the configured deceleration speed for your machine. (Else risk lost steps.) So, if you set higher feed rates, the probe will crash into the material. Why didn't I make this probe long ago? I don't know. C -----Original Message----- From: Chris Epicier [mailto:seuch...@yahoo.de] Sent: Tuesday, October 27, 2009 4:53 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Homing - zeroing - touch off Jeff I read your post with great interest. For me, it gave some very good insight. Like you, I do not have a repeatable tool length. I was wondering if I could get a kind of switch doing my touching off of the z-axis. The idea is as follows: - I have a parallel port based 3 axis mill driven by emc2 2.3.3 (soon 2.3.4) - I have a vacuum table, that is well enough even (I remill the surface when the wear plate needs to be replaced) - x and y are also repeatably within reference distance from home position - If I would add a small metal plate (say alu) into my vac table (could veven be on an spring mount), connect it to a wire, I could close an electric circuit when the tool touches that plate. If I was able to stop z-motion based on the closed electrical curcuit (we talk about say dc 4-6V) immediately, I would not have to jog to the position each time. This saves considerable time for me and sounds much more reliable to me as manual jogging. How would I be able to implement this? greets Chris ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
