Hi-lead ball screws are capable of 1m/sec (lead equal to or greater than the diameter).
If you want to try multiple drive motors, a rack and pinion becomes a very good option. You can use the multiple motors to take up any backlash free of charge, simply by placing a small amount of opposed bias in the pid loops. Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -----Original Message----- From: David Berndt [mailto:ber...@uberwin.com] Sent: Wednesday, April 11, 2018 11:27 PM To: emc-users@lists.sourceforge.net; Dave Cole <linuxcncro...@gmail.com> Subject: Re: [Emc-users] Large servo selection Hmm. Belting is a pretty interesting idea. Though for my application, the reverse motion of a crank/slider isn't a big negative. I've also been toying with combining a few servos smaller servos to get the work done. I've got no great idea on that yet mechanically or electrically. But taking advantage of the maximum torque vs rated torque on a 750w drive times 2 or 3 would seem to get me into the appropriate numbers and the smaller drives are much easier to find in single phase. Dave On Wed, 11 Apr 2018 22:19:24 -0400, Dave Cole <linuxcncro...@gmail.com> wrote: > Consider using a timing belt drive. Not exactly a timing belt, but a > cogged tooth belt. They make cogged tooth belting specifically for > linear actuators. > You can buy it several inches wide so 6 hp would not be a problem. I > did a servo drive setup to propel a machine carriage with such a belt. > I think the belt was about 2 inches wide. I think we used a 2 kw servo > motor with a gearbox. It could produce about a thousand of pounds of > pull. You can buy the belting by the meter or foot. I think it is > "AT" belting that is generally used for linear drives. Belts tend to > be a bit elastic when pulled hard so you may need a 3+ inch wide belt. > But it can certainly move quickly. The cost for the belting is quite > reasonable. > > > On 4/11/2018 3:21 PM, John Kasunich wrote: >> >> On Wed, Apr 11, 2018, at 3:08 PM, John Kasunich wrote: >>> >>> On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote: >>>> I'm looking to output about 1000lbf in a linear direction via a >>>> crank/slider or ballscrew >>> You don't mention the stroke length. Are you moving a few inches in a >>> fraction of a second, or several meters over several seconds? >> On further thought... >> >> Ballscrew requires unreasonably high RPM. >> >> Crank is very non-linear, and has major problems as stroke exceeds a >> couple inches - longer stroke means longer crank which means more and >> more torque is required. You never use more than a half-revolution of >> the crank, so some serious reduction will be needed between motor and >> crank. >> >> Have you considered roller chain? Keep the sprocket size small so the >> torque doesn't get crazy high, but you can use multiple revolutions of >> the sprocket to cover an unlimited stroke. Still going to require a >> gearbox; for a 1000 lbf load you will need a few thousand in-lbs (few >> hundred ft-lbs) of torque, which is a LOT for any motor. >> >> Interesting engineering problem to be sure. >> > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
