Thanks. I'll whip up a quick app for this. Nothing special. Could be done in as spreadsheet but where's the fun in that? John
> -----Original Message----- > From: Jon Elson [mailto:el...@pico-systems.com] > Sent: July-21-20 1:52 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Need help with Bostomatic BD18-2 to linuxcnc > > On 07/21/2020 02:54 PM, John Dammeyer wrote: > > Hi Jon, > > How did you come up with the constant 0.0318? > Long story. There's complicated formula to compute it from > the helix angle of the screw. > Too much fiddling around. So, if you had a drum with a > string wrapped around it that advanced the > axis as much as the leadscrew, it should be equivalent > (ignoring friction and diameter of the string). So, how big > would such a drum be? The circumference should be equal to > the pitch of the screw, in this case 0.2". So, what is the > radius of a circle with a 0.2" circumference? 2 Pi R = > Circumf. so > R = circumf./2 Pi so, 0.2 / (2 Pi) = 0.0318 > > Now, if you apply 10 in-Lb torque to a 5 TPI leadscrew, you > get 10 / 0.0318 = 314 pounds force. > > > > " So, that 100 oz-in motor (0.52 lb-ft) would > > produce 0.52/0.0318 = 16.35 lbs of linear force (neglecting > > friction)." > And, this was wrong due to a inch/foot mixup! > > 0.52 lb-ft is 6.24 in-Lb, and the linear force would be 196 Lbs. > > And how did you work out the 5G? > > > > "So, if your machine has a 200 Lb table, and the leadscrew > > were to produce 1000 Lbs linear force, > > it would accelerate at 5 G? > > > If you dropped the table on your toe (don't do this at home, > kids!) it would accelerate at 1 G. > if you push on the table with a force equal to 5 times it's > weight, that will accelerate at 5 G. > > Jon > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
