modified lower bracket for microphone holder

I needed the lower bracket with an M10 nut trapped for mounting to the stand. Additionally, the objects orientation was changed, so the bracket can be printed tilted with the printed layers aligned within the main stress direction. IMHO that makes the bracket arms more resilient to the strain from inserting and tigthening the microphone bracket. As you can clearly see, brick-shaped design is what I like.

2014-05-17: added wingnut (for M6 nut)

note: this thing is just the modified base part of the holder (and the wingnut) - the main holder is from http://www.thingiverse.com/thing:145635 (see attribution under remixed from)