Thanks. I'll post some more detailed photos when it's completed. :)

Jhautz, yea it has me worried too. I purchased my pinions on the specification from the seller of a 7mm face width, but they turned out to be 5mm wide when I got them. I'm going to try it anyway and see what happens. The spur gear is actually deformed so I'm going to be getting more made anyway - the guys who made this one refunded me for their bad work luckily. It feels like Nylon despite me requesting Delrin, so I suspect it won't last!