I am designing a Helmholtz coil system in autocad 2014. I mirror copied one of the coils so that I could have 2 coils making up the Helmholtz coils. Everything was okay at first, no problems. However a few days later I noticed one of the coils, disappeared on zooming in. Then a week later when I ressumed the drawing, the second coil had completely disappeared! Even in previous versions of the design in different files. Relaoding autocad doesn't correct it nor does restarting the computer. Can anyone help with this problem?
Thanking you in advance,
Brendan Darrer
P.S. the autocad file is attached (3d_helmholtz_606mmThick_4i.dwg) including a screenshot of the 3d autocad drawing - showing only one coil - the second coil is only part outlined by in parple lines that guided the drawing of the second coil.
![Autodesk Design & Make Report](https://forums.autodesk.com/t5/image/serverpage/image-id/1350519iCB55845EBFC43016/image-size/large?v=v2&px=999" "Autodesk Design & Make Report")
