Power Destroyer Walking Gears

these are my 1st and 4th samples(2nd and 3rd were a failure) of the gear all Hua-Chi Power Destroyers use for walking, it's a definite issue all of these have that the gears to make it walk just split, so i want to change that and give YOU the chance to also own a fully working Power Destroyer.
IMPORTANT: THE 2 STL FILES ARE DIFFERENT SIZED GEARS, SO DO NOT MIX THEM OR ELSE THE ROBOT WILL JUST CLICK. PRINT 3 OF EACH KIND AND TRY WHICH ONE WORKS BETTER FOR YOU.(mine worked better with the 4th on