Thickstrings and Mat, Your mentioning of domes got me started and I had to make one, It's made from scraps of 1/2" EMT since I have it. I got my info from domerama.com for a 3v 5/9 dome about 12' diameter. I chose there calculator over desertdomes.com because it makes a flat bottom with an odd frequency. I made jigs materials and tools on hand. I'll share more if anyone is interested. Here it is before I made the door opening. <a href="http://s1320.photobucket.com/user/bobwieser/media/Mobile%20Uploads/2014-09-20_15-44-39_154_zps034fa6c0.jpg.html" target="_blank"><img src="http://i1320.photobucket.com/albums/u529/bobwieser/Mobile%20Uploads/th_2014-09-20_15-44-39_154_zps034fa6c0.jpg" border="0" alt=" photo 2014-09-20_15-44-39_154_zps034fa6c0.jpg" style=""></a>
Bob.