Great design. I did have to file out the holes to make the axles fit through, but not a lot. It starts quite tight and hard to turn, but loosens up nicely as it is worked. Love the clips to hold everything on the axles. Very easy assemybl I thought the gears looked better flipped the other way than how the designer built his. The "neck" on the gears is the same size as the larger part on the axles - so it looks like a large axle that goes through. (This editor is terrible - it keeps moving the 'y' from the word "assembly" to the end of the text)..y.