I purchased on ebay a 3D printed compound gear that is supposed to enable metric threading on my Heavy 10. ? The gear appears to be printed well, and is equipped with a bronze bushing center for reduced wear and longer life. ? What I didn't get, however, is any instructions.? Can someone give me guidance on how to integrate it into the geartrain, and point me to a spreadsheet or PDF of a new threading/feed chart after the modification?