Understood! If you need only an estimate of the time rather than super accuracy you could: Calculate the circumference of the smallest circle (3.142 x diameter) Calculate the circumference of the largest circle (3.142 x diameter) Average the two circumferences Multiply the average circumference by the number of complete rotations Divide the total of the circumstances by the feed rate.
-----Original Message----- From: gene heskett <[email protected]> Sent: September 15, 2025 8:27 PM To: [email protected] Subject: Re: [Emc-users] EDM auto advance Q's On 9/15/25 11:49, [email protected] wrote: > I think that you need to calculate the length of an Archimedean spiral > to determine the time to move along it. This page provides a general > formula for arc length using calculus for spirals expressed in > parametric or polar form. > https://www.mathsisfun.com/calculus/arc-length.html Unforch Ken, while the above is no doubt correct, I still have 2 problems. Not your fault, mine, as my math education stops with simple 8th grade algebra, (I quit school and started fixing the first 30 tube tv's in '48) is problem #1, #2 is I haven't a clue where to find those characters on my utf-8 keyboard. I have done some work with cateranary's(sp?) but not since the '70's to check guy wire tensions on a 1000' Stainless tower after a legendary Nebraska blizzard left several tons of ice on the antenna, using the rifle scope derived intercepts on the wires. Had to make a homemade TDR to tell the tower crew where to take it apart to find the first of the line burnup that caused. Tower was a bit crooked but straightened as the weight went away as the ice ablated. Took around 11 days to thaw it all. I was caught at the site for 3 days w/o any food in the fridge, when I got plowed out I went to the drug store for my youngest's special formula and some eats for the rest of us, and drug it all the last mile to the farmhouse we were living in at the time, on a 2x6 throw rug slogging thru 2 to 4 foot drifts. Obviously I was a bit younger then. Now I'll be 91 in about 2 weeks. Thank you Ken. > -----Original Message----- > From: gene heskett <[email protected]> > Sent: September 15, 2025 11:37 AM > To: Enhanced Machine Controller (EMC) > <[email protected]> > Subject: [Emc-users] EDM auto advance Q's > > Actually 3 Q's, two of which Peter may be able to answer. > > 1; in a 7i76D, the 12 volt inputs need a signal of what duration to > reliably detect that a signal has occurred? And what is the maximum > voltage that can be applied to a 12 volt input? > > 2; how can I determine the predicted elapsed time for a 10 spiral > g2/g3 move which will expand in time as the diameter of the spiral grows? > > Thanks everybody. > > 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 > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > [email protected] > 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
