On Saturday 30 March 2013 22:30:04 dave did opine: > On Sat, 2013-03-30 at 17:34 -0400, Gene Heskett wrote: > > On Saturday 30 March 2013 17:32:05 cogoman did opine: > > > On 03/26/2013 01:21 AM, Gregg Eshelman wrote: > > > >> I am not sure you will see good acceleration. In fact, it is > > > >> > > > >> >always > > > >> >going to be less than 1g. This is because for any faster > > > >> >acceleration > > > >> >the strings go slack as the weighs don't fall fast enough. > > > > > > > > No need to go anywhere near that fast because an oxy-acetylene > > > > torch or plasma cutter can't cut that fast. This rig is most > > > > often used for cutting steel 3/4" thick or thicker. > > > > > > > Since counter weights are often used on Z axes on servo machines, > > > I > > > > > > once decided to calculate how much of a limit the acceleration due > > > to gravity would be. The metric calculations are left for you > > > folks across the pond. > > > > > > Acceleration due to gravity = 16 feet/second/second > > > > Uhh, when I went to school back in rural IA, in 2 feet of snow, uphill > > 2 miles both ways, gravity's acceleration was 32 feet per second per > > second. Did I go to the wrong school? > > > > > After 1 second the velocity can be 16 feet per second > > > > > > times 60 = 960 feet per minute (I love spreadsheets!) > > > > > > times 12 = 11520 inches per minute > > > > > > divide that by two, so half of that force can be applied to your > > > cable = 5760 inches per minute > > > > > > HERE'S WHERE I AM MAKING ASSUMPTIONS THAT MAY BE OFF BY A LITTLE. > > > > > > If I recall properly 1500 inches per minute is a FAST servo system. > > > > > > 1500/5760 = .26 ( assuming linear acceleration it should only take > > > .26 seconds to reach 1500 IPM) > > > > > > 1500/60 = 25 inches per second > > > > > > at 25 inches per second that servo system would travel 6.5 inches at > > > full speed while the gravity system would be accelerating to 1500 > > > IPM. Of course the servo system wouldn't be able to accelerate > > > instantaneously, so the counter weight would only slow a 1500 IPM > > > servo system down a little bit. > > > > > > I thought gravity would be much more of a limit too. > > > > > > -------------------------------------------------------------------- > > > ---- ------ Own the Future-Intel(R) Level Up Game Demo Contest 2013 > > > Rise to greatness in Intel's independent game demo contest. Compete > > > for recognition, cash, and the chance to get your game on Steam. > > > $5K grand prize plus 10 genre and skill prizes. Submit your demo by > > > 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124-176961-30367-2 > > > _______________________________________________ > > > Emc-users mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > Cheers, Gene > > Gene, > > But in physics there are often special cases. ;-) > My father would, in good weather, ride his 3 speed bike downhill to work > and downhill going home. > Now, of course this take a bit of explanation: We lived at 1230 ASL. > Work was at 920 ASL and when he finished work he rode the elevator to > the top of the dam at 1310 ASL and rode home. That (the road) > disappeared with the construction of the 3rd powerhouse at Coulee so > this special case no longer exists. :-) > > Dave
Good thing my coffee cup is empty. :-) I just knew somebody would have to call me on that. Actually, I rode a horse if the weather was above 10F, below she stayed in grandpa's own, much better sealed barn, nice & warm for the old mare, but the only barn (not near as tight as grandpa's) I could put her in for the day while I was in school was still 3/4 mile short, so I had to walk the rest of the way. Even in -15F weather, then I had to walk all the way, most of 2 miles. Snow days was a concept that hadn't made it to the little one room IA schoolhouses in 1940-41. ============ And I am still trying to figure out which of the 3 xy pairs is which on that center.c util. I /think/ if have it converted into an o50 sub in GCode, and its working for the first invocation, but not the 2nd, and its preclearing all its internal vars before loading the o50 call's [var] [var] [var] [var] [var] [var] in the o50 sub. So I am fairly sure its working with clean data to about 8 or 9 digits right of the decimal point. If you can cross check my work, and confirm which pair of xy's is which, I'll be glad to post what I have after about 8 hours of frustrating typing & testing in sim mode. Thanks Dave. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Carmel, New York, has an ordinance forbidding men to wear coats and trousers that don't match. I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ Own the Future-Intel(R) Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124-176961-30367-2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
