Posted by Craig Carmichael on May 23, 2012; 8:57pm
URL: https://forum.librecad.org/Circles-Angles-tp5706676.html

Hi,

I'm trying out L.cad to determine XY co-ordinates for a CNC drill to drill holes in round rotors. (Until now, I've been working out the co-ordinates via sines and cosines in a spreadsheet, and then creating the g-code program by hand from the numbers. Now to make a change I have to do it all over again.)

What I'm trying to draw/find seems simple enough...

1. circle with 4" radius (1 inch in from edge of 10" magnet rotor)
 2. 9 circles of 1" radius evenly spaced around this circle (motor coil positions)
  3. three points within each 1" circle (for mounting bolt holes) at .375" radius, at the outermost point from the main circle center, and 120 and 240 degrees from that.

I can draw the first (4" radius) circle fine. When I go to draw the 1" radius circles they snap to center on the  edge of the first circle (cool!), and I can see the angle in a box at the lower left, but there are fractions and I can't get it to exactly 40, 80, 120... degrees. Nor do I see anywhere to enter the angle numerically. After the circle is made, "properties" shows the x,y co-ordinate of the center, but not the angle WRT the first circle/origin.

Is there any way to get the 9 circles at the exact angles around the first one?

If so, I can try to get to step 3.

Thanks,
Craig