I don't see any relation between max acceleration and max speed. Acceleration is determined by (1) the mass of the table and (2) the torque the motor can produce while speed is determined by the max RPM of the motor.
It is very easy to buy a tiny motor with low torque that spins very fast. Or you can find powerful but slow motors. Multiplying the speed by three to find acceleration, if it works is just a coincidence. The factor could be 0.5 or 10. There are two whys to go. A mechanical engineer would start with a requirement for a certain speed and a certain acceleration. His boss would give him those goals and then he would select a motor and drive. The other way used by most amateurs is to just buy a motor that "seems right" and then test it to see what speed and a certain acceleration you can get from it. It both cases you end up iterating to the solution. The engineer has to tell his boss "Going that fast is going to make the machine very expensive. Are you sure you want those performance numbers?" The amateur looks at the results of testing and asking himself "Is it with it to make otherguess and try another motors or do I live with this one?" That said acceleration is related to speed. (acceleration) x (time) = (speed) example: (10 inch per second squared) x ( 0.5 seconds) = (5 inches per second) In theory, if you had enough time the speed could be anything but typically the motor only spins so fast and you hit some real-world limit. The bottom line is to test, find where it stops working reliably than to be conservative cut those test results in half, and use that as your limit. On Wed, Jul 22, 2020 at 9:09 AM John Dammeyer <jo...@autoartisans.com> wrote: > > Ho Jon, > > I've changed the subject line to be more relevant and corrected the gravity > value. > > Now we have 1703 In/Sec^2 for maximum possible acceleration given the load > and torque ratings. > > On my system in imperial units I have 2.5 inches/second and I randomly picked > the accel as 3x that. Does that mean I could set MAX_ACCEL to say 1700 and > get away with that or is that number abnormally high? I know I can try it > but I'd like to know if the math is accurate. > > MAX_VELOCITY = 2.5 > MAX_ACCELERATION = 7.5 > What I'm trying to do with this tool is to take out some of the guesswork or > the accidental divide instead of multiply. > > And second question. If someone is using metric units for their system what > units are used to describe MAX_VELOCITY and ACCEL? > Is it mm/minute? Or mm/second? Or meters/second? Is the weight specified > in grams or kg? > > I want to be able to make the checkbox convert the imperial < = > metric > correctly. > > > > Thanks > John Dammeyer > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
