On Wednesday 18 July 2018 00:57:55 Erik Christiansen wrote: > On 17.07.18 12:00, Gene Heskett wrote: > > On Tuesday 17 July 2018 10:00:36 andy pugh wrote: > > I'm much more familiar with something like lb/ft, how do I translate > > that into what I am currently tightening the er20 nut to?, which I'd > > estimate at 50+ lb/ft. So mentally I can't compare that to 80Nm. > > $ units > You have: 80 N m > You want: ft lb force > * 59.004972 > / 0.016947724 > > It may be hard to mentally convert, but your mechanical muscle > comparison matches exceedingly well. (50+ vs 59) > > > > If the disc is 100mm radius then it needs an axis force of 800N, > > > or 80kg. If the ballscrew on the axis is 5mm pitch then that > > > implies a motor torque of 0.6Nm. So even a relatively small > > > stepper can do it. > > The motor, then: > > You have: 0.6 N m > You want: oz force in > * 84.96716 > / 0.011769253 > > You probably have a stepper with more than 85 OzIn of torque within > reach. > > > That disc I'd estimate was no more than 50mm radius, doubling the > > required motor power. With less than 5.5" of Y motion available due > > to the Y drive conversion design limiting how far forward it can > > move, I'd be hard put to come up with a working 70mm radius for a > > 185 or 190 degree turn. > > That'd need at least a 120 OzIn stepper, or something like the other > link at the end of the comments. It doesn't have to take the nut off, > but could just loosen the one collet, using a separate motor, stepper > or DC. I think I'd like to make the tool magazine linear, along the > back of the table, so as not to eat up table space. If the nut motor > were reversed for odd tool slots, then there's be no need for an idler > gear between slots. > > Erik
i mentioned that reversal earlier. Gets rid of the idler gears and bearings to spin them. On something with table space to spare, yes. My G0704 doesn't have a lot of room as the tables max distance to the post is maybe 5.75". So basically anything I make has to swing in from the side. And TBT, needs support under the far end of the table to reduce the way friction when off center by 8" or more. Add the 15+ lb A axis mounted to the left end of the table right now, and I have to slow the homing final X move so a 425 motor can move it w/o slipping a few steps since the home switch is at the other end of the tables travel. I have even considered rigging a bar across the top of the post to serve as an anchor for a spring connected to the end of the table so the spring helps support the table when its off center. Shoemakers kids story, haven't found my round tuit yet. Been looking for that puppy for 4 decades now. ;-) It got lost when I moved from Rapid City SD to Caroll Nebraska in 1969. Frankly I need to do a bunch of plumbing with weed eater fuel line, and rig it for a 1 shot lube. I have to clean the ways and relube with a cotton ball or similar quite frequently, and the post gets a drink daily to control stiction when moving slow. The one shot would help, as would rigging for coolant. Mist is even better, but really wrecks the air in the shop. Takes hours for the fog to settle. I have, without a doubt, left something out, so post back to this list for clarifications in that event. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ 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
