The lower frame assembly is the next build step. The manual shows the lower frames being built, then the undrcarriage and then the upper and lower frames being bolted together. This doesn't actually make much sense.To build the lower frames as shown in the manual you have to mount the upper frames at the same time. Otherwsie a number of screw have nothing to screw into as the y should be screwing into the upper frames. However, for simplicity of diagrams the manual does a good job of showing what goes where. One task to complete before building any part of the lower frames is to check what screws you will be using to mount your motor. The motor mounting plate is drilled for 2.5mm screws. Some motors (such as the AON) use 3mm screws for motor mounting. If you need to use larger screws then the motor mount should be drilled now rather than later when it is very diffcult to perform this task due to the frames getting in the way. Lower frames parts Lower frames built Mounting upper frames to lower frames Mounting upper frames to lower frames Following the mounting of the upper frames onto the lower frames the undercarriage can be built and installed onto the lower frames. Undercart parts Undercart installed Back / Next