I was thinking more of a 1 shot like a G04, and was thinking something like G01.1. However I think you may be closer to the proper code spot in the G61 / G64 area since this ramping would be also used for arc segments. ( more likely helical moves ) Idea being that a single move would start at the existing feed rate and ramp velocity to the new feed rate evenly over the length of the move. Now if this were modal you could have it ramp the velocity over the course of several segments, but that is getting beyond the realm of feasability at this point. Use - this allows adjustment for constant spindle load while the engagement % of the tool in the cut might vary. In very light cuts the load might not be measureable but the load transfered to the part needs to be limited. I don't see anyone needing this as a modal feed type - I figure the command can be issued on each line it is required just like a feed rate is required for each move while using Inverse time feedrates. On the interpreter side it should be an error if the feed rate is undefined before the first feed motion command. Why someone might need this function: A good example is when the material ahead of the cutter is required for structural support and that attempting to do the cut in multible passes would cause the part to be too weak and maybe destroyed by the cutting forces. I run into these type of issues with various castings and I have to "manually" cut them with CNC by running in single block mode and using the feed overide as each part is cut. To: Greg Bentzinger <skullwo...@yahoo.com>; Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Sent: Thursday, December 26, 2013 11:14 AM Subject: Re: [Emc-users] Ramped feed rate.
Hi Greg, Sorry for taking so long to answer. I've been working on the trajectory planner recently, so I can try to weigh in on your question. First of all, I'm curious what the application for this would be. Do you use it as a "one-off" move, or would you run a whole program this way? It seems like this mode could useful when you have a program to do detailed profiling with short segments. The default planner would make a velocity profile that has more of a stair-step shape, since it will accelerate as fast it can to the requested speed. This is a minor change in the trajectory planner. The bigger issue is how we'd want to control this mode. One way could be to create a new G-code, similar to G61 / G64. It could also be done by HAL-pin, if you didn't need to switch between modes during a program. I'm curious what others think about this. Would anyone else find this useful? -Rob On Wed, Dec 18, 2013 at 7:17 PM, Greg Bentzinger <skullwo...@yahoo.com> wrote: (Ok here I am mumbling into a microphone before the crowd... ) > >But going way, way, way back ( Picture in your minds eye teletypes and paper >tape programs...) I had always wanted a ramped feed rate command. > >Like > >G1 X1. Z-.25 F20. >( ramp command) X4. Z-1. F5. > >So that the move from X1. Z-.25 to X4. Z-1. would start at F20. and slow to >F5. by completion of the move. > >This could be a one shot ( like a G04 ) or modal, or both. > >Another use would be for a part off lathe tool being fed in FeedPerMin vrs >FeedPerRevolution. > >Same could apply to feeding a tapered ream, start at F.02 end at F.002 ( FPR ) > >Often there are other easy ways to do things, but sometimes it would be the >best method - were it available. > >Just thinking outloud > >Greg > >------------------------------------------------------------------------------ >Rapidly troubleshoot problems before they affect your business. Most IT >organizations don't have a clear picture of how application performance >affects their revenue. With AppDynamics, you get 100% visibility into your >Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! >http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk >_______________________________________________ >Emc-users mailing list >Emc-users@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
