There is nothing like machine geometry that fits the job you want to do. :-)
> On Apr 12, 2024, at 9:08 AM, Stuart Stevenson <stus...@gmail.com> wrote: > > Good morning, > I am sitting here at 70 wondering how people get along without 5 axis. A > shop here in Wichita sent me 500 parts to run. He was running them on a 4 > axis mori seiki. The runtime was a little over an hour. He wanted to clear > machine time. He furnished programs, material, fixtures, cutters. The > envelope was 8 inches X 4 inches X 1 inch. We called them porkchops. Flat > bottom but with standing ribs at angles and contours. Long, small diameter > cutters to reach small corners. I programmed the parts for my 5 axis, made > new fixtures (a plate with locating bushings) and used much shorter > cutters. Machine run time was now 18 minutes. You CAN do 5 axis parts on 3 > axis and 4 axis machines BUT (it is a very big but) it takes more time and > effort. > > My maternal grandparents were born in 1894 and 1895, My paternal > grandparents were born in 1903 and 1904. They also had stories. > > regards > Stuart > > > On Fri, Apr 12, 2024 at 10:33 AM Chris Albertson <albertson.ch...@gmail.com> > wrote: > >> >> >>> All very true and well for someone equipt with the income and mental >> gear to use that chain of tools profitably. But I'm an old Iowa farm kid, >> we made what we needed. The "store" was 15 miles of horse drawn wagon over >> a mud road the county graded about 2x a year and all of a days ride in a >> wagon away. So we grew it, or made it from the woodyard, whatever. 2 miles >> to the 1 room school, I rode an old gentle mare the first mile but had to >> walk the 2nd mile because there wasn't a barn for the mare during the day >> any closer to the school when the weather was bad. Grandpa across the road >> had electricity, a 32 volt delco wet glass batteries, charged by a zenith >> windcharger. The prop broke, so mother who was the only girl in the 1929 >> class on aviation technology at Des Moines Tech Hi School, proceeded to >> teach her father how to carve the wing chord in a new prop. Worked well in >> less wind than the one we could get from Chicago. That led to grandpa >> having the first electric washing machine in Madison County Ia when the >> Maytag hit & miss tried to start backwards, broke the starter gears and >> grandma's ankle. A wagon load of shelled corn went to town, and was >> replaced by an electric motor and enough heavy wire to convert the Maytag. >> I still wear scars on one hand from getting it caught in the wringer when I >> was 5. We did not want for anything, we "made do" That is a hard habit to >> outgrow. >> >> But today you own a computer, lots of CNC equipment, a 3D printer and >> education is free and just a mouse click away. None of the stuff I wrote >> about costs even one dollar. I’m the old ririred guy now. Fusion360 is >> free to use. I can print ther prats and then if. Needed sand the same >> design to CNC machine or to an injection molder >> >> I think you are right about relativity, Einstein very much admired James >> Clerk Maxwell. Someone said Einstein ”stood on the shoulders of Newton”. >> Einstein corrected him and said “I stood on Maxwell’s shoulders”. >> >> Thanks for the story. I always like to hear those “when I was a kid…” >> stories. My four grandparents were born in 1902 through 1911 they could >> talk about the days before radio broadcasting and one-room schoolhouses. >> One grandfather was a professional boxer in the 1920s and traveled a lot. >> But even more interesting to me, my wife’s parents and uncles were born in >> pre-war Japan. I think they lived through more change than any living >> American. Sadly the last of them is in very poor health. My wife is >> visting her mom in Tokyo right now. >> >> Maybe when I am older I will talk about the days of manually driven gas >> cars. >>> >>>> >>>>> >>>>> My electronics education is 100% self taught. My mother gave me an IQ >> good enough to pass the CET test w/o cracking a text to study it. I >> understand the physics of it including Relativity. Electronics and >> Relativity go hand in hand, cannot be separated. >>>>> >>>>>>>>> On Apr 10, 2024, at 12:09 AM, gene heskett <ghesk...@shentel.net> >> wrote: >>>>>>>>> >>>>>>>>> On 4/10/24 01:57, John Dammeyer wrote: >>>>>>>>>> A friend and I have been discussing exactly how to write the >> G-Code to >>>>>>>>>> create a spiral scroll. >>>>>>>>>> His rotary table 90:1 reduction with a 1600 micro-step motor >> could be set up >>>>>>>>>> to move N steps for each step of the X axis to create the >> spiral. But that >>>>>>>>>> approach seems clumsy. >>>>>>>>>> Say I wanted to cut a scroll with a 6mm pitch using a 3mm cutter. >>>>>>>>>> Without using G2 or G3 it's really just a triangle isn't it? >> Move rotary >>>>>>>>>> table distance A and move X axis distance A'. Do it in small >> enough >>>>>>>>>> increments and you get a spiral. But I feel like I'm missing >> something >>>>>>>>>> really simple. >>>>>>>> Do you need a rotary table to cut a spiral? It is just a series >> of locations in (x,y). OK, if you wanted to use only (say) the X and A >> axis then you should use polar coordinates, not cartesian. The equation of >> a spiral on polar coordinates is very simple. Then you evaluate itat many >> thousands of points and at each point write gcode to “cut to” that point. >> You would not need the rotary table. >>>>>>>> Also why think in micro-steps and worm gear rates, you are using >> LCNC to do the kinematics, Use millimeters. >>>>>>>> I think this problem shows that in some cases you really can not >> write the gcode by hand. FOr continous curves in (x,y) there might be >> 100,000 or more lines of code in the file, especially if you don’t do the >> cut in one pass. You would nee towrite software to generate the g-code. >> Or use existing software, a lot of CAD systems will do this for you >>>>>>>>> First, a 90/1 is quite high. I have two rotary's, both consisting >> of a 3NM 3phase stepper/servo I made by combining the 3NM motor with a 5/1 >> worm. Using a screw in the worms output hub as a single prox sensor index >> pulse generator. To calibrate a complete rev, I measure the steps by >> starting the count on the 3rd turn ans stopping the count on the 103rd >> turn, which gives me a scale*100. Shift the decimal point 2 places left >> this becomes the scale for the axis in the .ini file. All this math in >> linuxcnc is floating point so I can ask it for 33.333 degrees and it will >> run to what it thinks is 33.333 degrees. This stepscale: >>>>>>>>> STEPSCALE = 22.22222222222 = 1 degree >>>>>>>>> So one count is about 1/22.22222222222 degrees, probably less than >> the backlash in the rvs39 worm, a pretty cheap worm. >>>>>>>>> >>>>>>>>> Currently to make one of my maple vise screws, starting at 0 >> degrees its around 60,000 degrees it turns for around 400 mm of screw that >> y travels. Then I lift the tool, turn it another 180 degrees, re lower the >> tool and bring y back to zero and b=180. Makes a perfect two start buttress >> thread. The B is turning, in perfect sync with the Y motion, at something >> in the 300 to 400 rpm range. That 3NM motor is heating but not dangerously >> so. >>>>>>>>> >>>>>>>>> There is no reason you couldn't lay it down to make a C drive, and >> simultaneously drive X Z & C to carve an impeller in a quite serviceable >> scroll. >>>>>>>>> >>>>>>>>> The versatility of the closed loop stepper/servo, which does >> EXACTLY what the TP tells it to do, without a PID in the path, is amazing. >> I have them rigged to e-stop linuxcnc in about a millisecond if they make >> an error, like losing a step. Tested till the cows come home, has yet to >> happen working a job. I haven't hobbed any gears, but it certainly seems >> accurate enough to do it. >>>>>>>>> >>>>>>>>>> Suggestions? >>>>>>>>>> Thanks >>>>>>>>>> John >>>>>>>>>> _______________________________________________ >>>>>>>>>> Emc-users mailing list >>>>>>>>>> Emc-users@lists.sourceforge.net >>>>>>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>>>>>> . >>>>>>>>> >>>>>>>>> Cheers, Gene Heskett, CET. >>>>>>>>> -- >>>>>>>>> "There are four boxes to be used in defense of liberty: >>>>>>>>> soap, ballot, jury, and ammo. Please use in that order." >>>>>>>>> -Ed Howdershelt (Author, 1940) >>>>>>>>> If we desire respect for the law, we must first make the law >> respectable. >>>>>>>>> - Louis D. Brandeis >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> Emc-users mailing list >>>>>>>>> Emc-users@lists.sourceforge.net >>>>>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>>>> _______________________________________________ >>>>>>>> Emc-users mailing list >>>>>>>> Emc-users@lists.sourceforge.net <mailto: >> Emc-users@lists.sourceforge.net> <mailto:Emc-users@lists.sourceforge.net> >> <mailto:Emc-users@lists.sourceforge.net> >>>>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>>> >>>>>>> Cheers, Gene Heskett, CET. >>>>>>> -- >>>>>>> "There are four boxes to be used in defense of liberty: >>>>>>> soap, ballot, jury, and ammo. Please use in that order." >>>>>>> -Ed Howdershelt (Author, 1940) >>>>>>> If we desire respect for the law, we must first make the law >> respectable. >>>>>>> - Louis D. Brandeis >>>>>>> >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Emc-users mailing list >>>>>>> Emc-users@lists.sourceforge.net <mailto: >> Emc-users@lists.sourceforge.net> <mailto:Emc-users@lists.sourceforge.net> >> <mailto:Emc-users@lists.sourceforge.net> >>>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>> _______________________________________________ >>>>>> Emc-users mailing list >>>>>> Emc-users@lists.sourceforge.net <mailto: >> Emc-users@lists.sourceforge.net> <mailto:Emc-users@lists.sourceforge.net> >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>> >>>>> Cheers, Gene Heskett, CET. >>>>> -- >>>>> "There are four boxes to be used in defense of liberty: >>>>> soap, ballot, jury, and ammo. Please use in that order." >>>>> -Ed Howdershelt (Author, 1940) >>>>> If we desire respect for the law, we must first make the law >> respectable. >>>>> - Louis D. Brandeis >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Emc-users mailing list >>>>> Emc-users@lists.sourceforge.net <mailto: >> Emc-users@lists.sourceforge.net> >>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >>> Cheers, Gene Heskett, CET. >>> -- >>> "There are four boxes to be used in defense of liberty: >>> soap, ballot, jury, and ammo. Please use in that order." >>> -Ed Howdershelt (Author, 1940) >>> If we desire respect for the law, we must first make the law respectable. >>> - Louis D. Brandeis >>> >>> >>> >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > > -- > Addressee is the intended audience. > If you are not the addressee then my consent is not given for you to read > this email furthermore it is my wish you would close this without saving or > reading, and cease and desist from saving or opening my private > correspondence. > Thank you for honoring my wish. > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
