Thank you Kenneth for a concise explanation. On Sun, Nov 4, 2018, 4:07 PM Kenneth Lerman <[email protected] wrote:
> Well, three arc minutes is a 20th of a degree. There are 20 * 360 = 7200 of > them in a circle. A circle with a diameter of 10 inches has a circumference > of 10 * pi or 31.4 inches. Divide that by 7200 -> .004. > > So, you can probably answer the question. Imagine a flat piece of ground > steel 10 inches square by 1/2 inch thick. Indicate it in to be perfectly > horizontal. Then flip if over to the other side. Now run your indicator > over that piece of steel. Is four thousandths too large an error? (The edge > to edge difference will be twice that.) > > I think the answer is that is not precise enough, but your answer will > depend on your application. > > Ken > > On Sun, Nov 4, 2018 at 3:57 PM jeremy youngs <[email protected]> wrote: > > > Hello all ,I just purchased several hd brand gear heads . I have a > question > > about the backlash call out of 3 arc minutes. One of these is fairly > large > > and I would like to use it as an engine block rollover . I have a 10*50 > > comet and I want to attach my van Norman boring bar to it . This will > > eliminate having to lift that 250 lbs and allow measurement of bore > without > > disturbing the bar. > > My question is , is 3arc minutes too much for this process ? And could > > backlash be effectively reduced by putting a brake at the opposite end of > > the rollover fixture and preloadi g the gear head ? Obviously attention > to > > that detail would be required. Thanks fellas > > > > _______________________________________________ > > 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 > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
