FreeCAD: Accurately rotate a object around a different axis of your choice

hi viewers and welcome to the channel and today i'm answering a question about rotation now the question is if we have say a cube in here if we look at where this rotates around we go to view toggle axis cross you can see that our point of origin for our world coordinates is here and this cube has been created at point zero zero zero and if i transform this we can see that when we rotate this object it rotates around this vertex here let's say if i wanted to rotate it around well this vertex or through this edge so these top vertices so it rotates around here how do i do that well freecad gives you a tool to allow you to have more precise control over the rotation you can't do it from the axis here well you can but it's actually quite hard this is not in degrees so if i added 45 degrees here this wouldn't actually work it's come out of our edit mode and i put 45 degrees on the y and 45 degrees on the z you can see this isn't working so how do we set this axis so the problem that we've got is that these values are not in degrees so how do we make this easier on ourselves well freecad gives you a tool so if i click on the cube come up to edit and come down to placement we get this panel here and this gives you a number of options to actually rotate this what i'm going to do is just reset this if i click on reset this object moves back to where it originated from so you've got the x y and z so these are all translations so we can use this to translate our object so i'm just using the mouse wheel to move this up and down to move this across this axis so put it back to where it was and the angle rotation angle if we drop this down this gives us an x y and z to rotate round where we can actually use degrees so we can say 45 degrees around the x and 45 degrees around the y et cetera you can see how that's changing but let's say if we wanted to change this and rotate around a different point so i want to rotate say around this vertex here rather than this vertex this is where the center comes in handy so i can select the vertex come in and select points this changes the center of rotation so you can see we've got x10 and z10 now when i rotate say around the x-axis we can see that's rotating around this vertex here through that and rotate it around y and you can see how that's rotating and finally the z so we can set this to a rotation by using the x y and z and using the center i can see how that's rotated there there's also this supply incremental changes if i click that and hit reset we've got the x y and z here but you can see this is being placed some distance away from this point if we look back to the model and come down to the position this is 4 along the x-axis so what's happened is when we go back to the task you can see that i know it's saying x y and z of zero it's actually taken the placement of this object and just zeroed everything out and used that as the base point so i know that's four millimeters away from that point there along the x we now can translate this say another four millimeters or if we want to go back to the point of origin we need to go minus four so these are incremental changes the same with the axis if this had some rotation at first so let's come into the angle and just place a 90 degree rotation on there let's try 45 so it's 45 degrees like so i'm going to the tasks you can see that has a rotation there got minus 4 back and it hasn't added that rotation on here so anything done from here is one degree more or an increment of degrees more than our original position and rotation let's reset this and i'm just going to uncheck this apply increment and just reset so we've reset the whole object back to the point of origin now we select more than one point to rotate around so i can click this point come round and select this point in here set points you see that the center has changed to 555 and we can start change the angle and it will rotate around those points hit reset and select a different point so if i hit select point this tells you what to select so this gives you a nice description of how this actually works so if i wanted to rotate around say a point on this face here now if i click that it's where the mouse pointer first clicked and if i select points it will actually calculate where that point is and we can make some adjustments in here just to get it into the correct position or we can use the center of mass unfortunately it doesn't show where this point is sitting in 3d space this placement is not carried over and kept when we come out of this so we can apply a rotation say i can apply a rotation around this axis here it's that point and then rotate this let's use the angle same like this apply and hit ok so that's applied but if i hit right click and transform we're still at the point of origin so our axis hasn't changed it's just the rotation around that access so it's a quick video of how to use the placement tools i hope this answers the question and i hope to see you again soon if you like what you're seeing please subscribe to the site i also have a co-fire or a coffee site that you can donate to if you so desire and that's at ko hyphen fi.com for slash min g0 also run a patreon where you can subscribe and get extra content and that's at www.patreon for slash mango jelly solutions any money that's kindly donated will be used to span the channel thanks a lot for watching and subscribing and i'll see you again soon

Channel: MangoJelly Solutions for FreeCAD

Views: 20,933

Keywords: CAD, three, 3D, CNC, Printing, solidworks, autoCAD, freecad 0.19, freecad 19, freecad basics, basic course, fundamentals, learn freecad, freecad beginners, freeCAD 0.20

Id: DZJ_6mkyiLo

Length: 7min 54sec (474 seconds)

Published: Mon Jul 04 2022