[Emc-users] EMC2 and 4th axis in milling: specifying speed and angular velocity?
I am not too far from adding a 4th axis to my Bridgeport Interact mill. The 4th axis will be a servo driven rotary table that sits vertically on the milling table, so that the axis of the rotary ta ble is parallel to X. I have a question, inspired by a recent discussion. Let's say I wanted to mill a helical spiral. Can I use EMC2 to instruct the milling table to move along X at a given velocity, while at the same time, the rotary table is turning with another given angular rotational speed. In other words, can I specify two speeds, one for XYZ move and another for the angular speed? I apologize in advance if I used wrong terminology. -- What happens now with your Lotus Notes apps - do you make another costly upgrade, or settle for being marooned without product support? Time to move off Lotus Notes and onto the cloud with Force.com, apps are easier to build, use, and manage than apps on traditional platforms. Sign up for the Lotus Notes Migration Kit to learn more. http://p.sf.net/sfu/salesforce-d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC2 and 4th axis in milling: specifying speed and angular velocity?
Igor Chudov wrote: I am not too far from adding a 4th axis to my Bridgeport Interact mill. The 4th axis will be a servo driven rotary table that sits vertically on the milling table, so that the axis of the rotary ta ble is parallel to X. I have a question, inspired by a recent discussion. Let's say I wanted to mill a helical spiral. Can I use EMC2 to instruct the milling table to move along X at a given velocity, while at the same time, the rotary table is turning with another given angular rotational speed. In other words, can I specify two speeds, one for XYZ move and another for the angular speed? You can't specify two speeds, but you can decide how much to rotate the A axis (A is parallel to X) during the XYZ move. This is how the manual describes combined linear and rotary motion: If any of XYZ are moving, F is in units per minute in the XYZ cartesian system, and all other axes (UVWABC) move so as to start and stop in coordinated fashion So, if you want to make a helical groove that wraps around the workpiece 3 times, you need to perform a 1080 degree move (3 * 360) along with whatever the XYZ move is: G1 X 3 A 1080 F 1 The line above will make a single groove that wraps around the stock 3 times, with 1 inch spacing between, and it will take 3 minutes to complete (F1 for 3 inches = 3 minutes). So basically the rotational speed is adjusted so that the rotation takes the same amount of time as the linear motion. - Steve -- What happens now with your Lotus Notes apps - do you make another costly upgrade, or settle for being marooned without product support? Time to move off Lotus Notes and onto the cloud with Force.com, apps are easier to build, use, and manage than apps on traditional platforms. Sign up for the Lotus Notes Migration Kit to learn more. http://p.sf.net/sfu/salesforce-d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC2 and 4th axis in milling: specifying speed and angular velocity?
Stephen, thanks, this is a wonderful way to implement this! i -- What happens now with your Lotus Notes apps - do you make another costly upgrade, or settle for being marooned without product support? Time to move off Lotus Notes and onto the cloud with Force.com, apps are easier to build, use, and manage than apps on traditional platforms. Sign up for the Lotus Notes Migration Kit to learn more. http://p.sf.net/sfu/salesforce-d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC2 and 4th axis in milling: specifying speed and angular velocity?
Igor Chudov wrote: Let's say I wanted to mill a helical spiral. Can I use EMC2 to instruct the milling table to move along X at a given velocity, while at the same time, the rotary table is turning with another given angular rotational speed. You can't specify two different feedrates. The feedrate applies to the X motion, the A axis follows along so that it completes at the same time as the X move. So, you would code someting like : G01 X1 F50 Z-0.1 F5 X2.345 A360 F7.5 Z1 EMC computes feedrate based solely on the X distance, ignoring the contribution of the A rotation. Jon -- This SF Dev2Dev email is sponsored by: WikiLeaks The End of the Free Internet http://p.sf.net/sfu/therealnews-com ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC2 and 4th axis in milling: specifying speed and angular velocity?
On Wed, Dec 08, 2010 at 09:00:57AM -0500, Stephen Wille Padnos wrote: This is how the manual describes combined linear and rotary motion: If any of XYZ are moving, F is in units per minute in the XYZ cartesian system, and all other axes (UVWABC) move so as to start and stop in coordinated fashion Because this can be confusing if you then switch between combined and angular-only moves, also consider the hint in G Code Best Practices http://www.linuxcnc.org/docs/html/gcode_overview.html#r3_8 which says Because the meaning of an F-word in feed-per-minute mode varies depending on which axes are commanded to move, and because the amount of material removed does not depend only on the feed rate, it may be easier to use G93 inverse time feed mode to achieve the desired material removal rate. -- This SF Dev2Dev email is sponsored by: WikiLeaks The End of the Free Internet http://p.sf.net/sfu/therealnews-com ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
