Well from what i have been playing with you want enough space between gears so they dont rub against each other and you dont want to much play inside the mechbox so the gears dont grind. But your gears should spin freely inside the mechbox when the box is screwed together, I would have to say is the most time consuming thing you have to do. Or just buy a modular gear set, HEHE!
watch this on Mechbox.com Where I learnt alot,
http://www.mechbox.com/mechbox/v2-me...g-upgrade.html
