This might be a stupid question, but why are g2/g3 considered archaic? I'm asking only because I use biarc approximation (which outputs g2/g3 sequences) to render cubic bezier curves and I assumed this would result in smoother curves than an approximation using tiny line segments (and generally faster machine movement). Do modern machines just depend on G64 blending to get the smoothness and speed? I wrote a g code plugin for Inkscape (because gcodetools wasn't working properly for what I needed) which is why I'm interested in this topic. I'm relatively new to all this.
ok maybe archaic is not the right word, all modern cam systems develop line segments to follow the spline more precisely . understand we are not talking about making circles or counterbores but following 3d nurbs splines. and no the machines do not rely on g64 but instead utilize infinite look ahead to keep with the blending . and generally the cm system itself will change feed rates to keep the motion smooth . the point is that high performance cam will never code in g2 g3 for complex surface lofting and will always output segments . now if it is hand coded this is a different thing. mastercam allows you to set your post processor up to match thdynamics of the machine . wihtout infinite look ahead you will be slowed .so in a nutshell 2.5 d works ok with g2 g3 , lofted surfaces dont and the trend is to produce programs through software . so i see infinite lookahead as a practical necessity in the project, especially if we want to reach high end commercial users . g2 and g3 do the same thing they interpolate small xy movements to makethe arc they however do it at the resolution of the machine and controller and cannot be changed readily and would always have to be changed to effect different resolutions . with software generating code any necessary resoultion becomes a mouse click away aith no need to affect the machine parameters. so if one side of the part can be roughed in and the other needs a high level finish it is readily accomplished without modifying machine parameters . 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UCC 1-103 1-308 ALL RIGHTS RESERVED WITHOUT PREJUDICES jeremy youngs On Fri, Jun 14, 2013 at 11:01 PM, < [email protected]> wrote: > Send Emc-developers mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.sourceforge.net/lists/listinfo/emc-developers > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Emc-developers digest..." > > > Today's Topics: > > 1. Re: looks like the K9-SmorgasBoard will make it to Wichita > (Ian McMahon) > 2. Re: Emc-developers Digest, Vol 86, Issue 23 (Claude Zervas) > 3. Re: Emc-developers Digest, Vol 86, Issue 23 (andy pugh) > 4. Re: Finally, A Proposal (Jon Elson) > 5. Re: Finally, A Proposal (Jon Elson) > 6. Re: Finally, A Proposal (EBo) > 7. Re: Finally, A Proposal (Matt Shaver) > 8. Re: Finally, A Proposal (Matt Shaver) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 14 Jun 2013 13:42:35 -0400 > From: Ian McMahon <[email protected]> > Subject: Re: [Emc-developers] looks like the K9-SmorgasBoard will make > it to Wichita > To: EMC developers <[email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset=us-ascii > > Oh, I was more interested in it as a development testbed. I'm already > working with an fpga cape on the BBB, and I have similar goals as you for > exploring possibilities for future specialized products. > > > On Jun 14, 2013, at 12:30 PM, Steve Stallings <[email protected]> > wrote: > > > > > Well, as stated when the K9 was first described, it was > > created as a development tool and we are not selling it > > as a product. Only a few will be built. > > > > It has two purposes. > > > > The first is to help with getting LinuxCNC working on the > > BeagleBone. As a software development platform, it comes > > with a few of almost everything we could think of for > > testing purposes. > > > > It is not a good foundation for building a regular machine. > > For simple machines it far to complicated and it is time > > consuming to build. On the other hand, it does not have > > enough industrial interface hardware for large CNC machines. > > > > Lots of progress has already been made on moving LinuxCNC > > to the BeagleBone platform and most of the dust will probably > > be settled by the time our Wichita meeting is over. > > > > The second purpose was to help us explore what people really > > expect and need from a LinuxCNC system running on a BeagleBone. > > After that gets sorted out, real products will follow. > > > > Please let us know what you feel is necessary for a practical > > product, and for what type of machine you are expressing your > > opinions. > > > > Thanks, > > Steve Stallings > > > > > >> -----Original Message----- > >> From: Ian McMahon [mailto:[email protected]] > >> Sent: Thursday, June 13, 2013 11:16 PM > >> To: EMC developers > >> Subject: Re: [Emc-developers] looks like the K9-SmorgasBoard > >> will make it toWichita > >> > >> Wow, that's quite a board! > >> > >> I'm not going to be able to make wichita, but I'd like to get > >> my hands on one. Are they gonna be for sale? (populated or not) > >> > >> Ian > >> > >> > >> On Jun 13, 2013, at 11:06 PM, "Steve Stallings" > >> <[email protected]> wrote: > >> > >>> Well we got the boards and have one mostly built. > >>> > >>> Lots of testing and debug remain, but at least the > >>> power system functions and the BeagleBone runs in > >>> place on the K9. > >>> > >>> The goal is to have two running boards at the show > >>> along with enough tools and gizmos to do some serious > >>> testing of both hardware and software. > >>> > >>> Here is a photo of the first board: > >>> > >>> http://www.pmdx.com/k9/K9-first-photo.JPG > >>> > >>> Cheers, > >>> Steve Stallings > >>> > >>> > >>> > >> -------------------------------------------------------------- > >> ---------------- > >>> This SF.net email is sponsored by Windows: > >>> > >>> Build for Windows Store. > >>> > >>> http://p.sf.net/sfu/windows-dev2dev > >>> _______________________________________________ > >>> Emc-developers mailing list > >>> [email protected] > >>> https://lists.sourceforge.net/lists/listinfo/emc-developers > >> > >> > >> -------------------------------------------------------------- > >> ---------------- > >> This SF.net email is sponsored by Windows: > >> > >> Build for Windows Store. > >> > >> http://p.sf.net/sfu/windows-dev2dev > >> _______________________________________________ > >> Emc-developers mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-developers > >> > > > > > > > ------------------------------------------------------------------------------ > > This SF.net email is sponsored by Windows: > > > > Build for Windows Store. > > > > http://p.sf.net/sfu/windows-dev2dev > > _______________________________________________ > > Emc-developers mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > ------------------------------ > > Message: 2 > Date: Fri, 14 Jun 2013 15:15:23 -0700 > From: Claude Zervas <[email protected]> > Subject: Re: [Emc-developers] Emc-developers Digest, Vol 86, Issue 23 > To: EMC developers <[email protected]> > Message-ID: > < > ca+r_aj6qp4cvgh3uamq3bg1hmwbb8oix_w1rx-1v0g9ggqo...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > > jeremy youngs wrote: > > ... > > > while this is not what you would like to do this is how all high end > > > commercial cam systems do it . programming in g2 g3 and g 17 , 18 , 19 > > are > > > archaic and do not fit the conventional real world model of production > > > today . > > ... > > > > This might be a stupid question, but why are g2/g3 considered archaic? I'm > asking only because I use biarc approximation (which outputs g2/g3 > sequences) to render cubic bezier curves and I assumed this would result in > smoother curves than an approximation using tiny line segments (and > generally faster machine movement). Do modern machines just depend on G64 > blending to get the smoothness and speed? > I wrote a g code plugin for Inkscape (because gcodetools wasn't working > properly for what I needed) which is why I'm interested in this topic. > I'm relatively new to all this. > > thanks, > - Claude > > > ------------------------------ > > Message: 3 > Date: Fri, 14 Jun 2013 23:32:08 +0100 > From: andy pugh <[email protected]> > Subject: Re: [Emc-developers] Emc-developers Digest, Vol 86, Issue 23 > To: EMC developers <[email protected]> > Message-ID: > <CAN1+YZV5mLxG6gq=QhbKHUp9wq62Njmij6tFrHsjACiR= > [email protected]> > Content-Type: text/plain; charset=ISO-8859-1 > > On 14 June 2013 23:15, Claude Zervas <[email protected]> wrote: > > > This might be a stupid question, but why are g2/g3 considered archaic? > > It may be because the CAM systems are using STL (or similar polygon > based systems) in which there actually are no arcs. > > -- > atp > If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto > > > > ------------------------------ > > Message: 4 > Date: Fri, 14 Jun 2013 20:52:23 -0500 > From: Jon Elson <[email protected]> > Subject: Re: [Emc-developers] Finally, A Proposal > To: EMC developers <[email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > andy pugh wrote: > > On 14 June 2013 15:03, Matt Shaver <[email protected]> wrote: > > > >> Should, for > >> example, the HAL be installable as a stand alone system (without the > >> CNC part of linuxcnc)? That was John Kasunich's original idea. IIRC > >> he was going to call it 'BLOCS'. I'm sorry that, at the time, I didn't > >> push him in that direction. > >> > > > > To a large extent it is. I do nearly all my testing in what amounts to > > a HAL-only environment. I have even set up machine controls in that > > way. (ie, halrun + stepgen + PyVCP + custom components) > > > And, I agree that we should keep this option to run hal standalone. > > Jon > > > > ------------------------------ > > Message: 5 > Date: Fri, 14 Jun 2013 20:56:32 -0500 > From: Jon Elson <[email protected]> > Subject: Re: [Emc-developers] Finally, A Proposal > To: EMC developers <[email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Kent Reed wrote: > > I am essentially out of loop (I'm in the hospital cafeteria at the > moment) > > as we struggle to to halt my wife's precipitous decline > We've been following her (and your) course with sympathy. > We will be thinking of you both at the fest. > > Jon > > > > ------------------------------ > > Message: 6 > Date: Fri, 14 Jun 2013 20:18:53 -0600 > From: EBo <[email protected]> > Subject: Re: [Emc-developers] Finally, A Proposal > To: <[email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset=UTF-8; format=flowed > > On Jun 14 2013 11:32 AM, Kent Reed wrote: > > I am essentially out of loop (I'm in the hospital cafeteria at the > > moment) > > as we struggle to to halt my wife's precipitous decline but I can't > > stop > > myself responding to this. > > Our hears go out to us... > > EBo -- > > > > > ------------------------------ > > Message: 7 > Date: Fri, 14 Jun 2013 21:48:02 -0400 > From: Matt Shaver <[email protected]> > Subject: Re: [Emc-developers] Finally, A Proposal > To: [email protected] > Message-ID: <20130614214802.1e8bc7c7@Matt> > Content-Type: text/plain; charset=US-ASCII > > On Fri, 14 Jun 2013 09:40:06 -0600 > Sebastian Kuzminsky <[email protected]> wrote: > > > We have this (slightly out of date, and doesn't cover all the info > > Matt listed): > > > > > http://www.linuxcnc.org/docs/2.5/html/code/Code_Notes.html#_architecture_overview > > This, but at multiple complexity levels. We need to add one to two > orders of magnitude to the detail level. A textual _Theory of > Operation_ for each operational block would help a lot too. > > > I'm interested in helping produce an updated architecture diagram in > > Wichita. I have a branch somewhere with the beginnings of an updated > > diagram... > > See you there! > > Thanks, > Matt > > > > ------------------------------ > > Message: 8 > Date: Fri, 14 Jun 2013 22:36:16 -0400 > From: Matt Shaver <[email protected]> > Subject: Re: [Emc-developers] Finally, A Proposal > To: [email protected] > Message-ID: <20130614223616.5ec82e8e@Matt> > Content-Type: text/plain; charset=US-ASCII > > On Fri, 14 Jun 2013 10:12:58 -0500 > Jon Elson <[email protected]> wrote: > > > I took a quick look around, and I couldn't find anything that looked > > like EMC source, but it might be there in a compressed file. > > I've been rooting around for a couple3 hours and have the start of a > small pile, all paperwork so far (and a coffee cup). I'll bring any old > CDs I can find too. Individually, no one thing looks that impressive, > but all of it together might be revealing. > > Thanks, > Matt > > > > ------------------------------ > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by Windows: > > Build for Windows Store. > > http://p.sf.net/sfu/windows-dev2dev > > ------------------------------ > > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > End of Emc-developers Digest, Vol 86, Issue 34 > ********************************************** > ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
