Alright, I playtested this a few times, and, it's way too slow for Modern affinity. I wasn't getting enough land, and I found myself not able to cast Master of Etherium or Etched Champion consistently until turn 5 or 6. You seem to be able to afford the Glimmervoid s and the Blinkmoth Nexus , So What I'm going to suggest shouldn't be out of your price range.
Other good additions are Tezzeret, Agent of Bolas , Thoughtcast , Vault Skirge , Signal Pest , Springleaf Drum , and Arcbound Ravager . Although if you go the Ravager route, Don't overlook Disciple of the Vault .
Here's My Modern Affinity deck; deck:cranial-plating-is-bawssauce, Just in case you want to look it over and see something helpful I may have missed.