Spooder Gets Its Legs

For my birthday this year, my family gave me a day: all of 27 October, to build Spooder, the hexapod from Upping the Ante for Next Year’s Career Day. Its frame had stood half-built since February 2024. By the evening five of its six legs were built and a second one was on the frame, and the day ended there only because I ran out of M3×12 countersunk screws.

The strangest find of the day was inside a servo. One of the MG996Rs bulged slightly where it pushes into its printed part, and I blamed the print: I reprinted that part a couple of times before I looked at the servo itself. A loose screw had got into its casing when it was put together at the factory, and quality control hadn’t caught it. I got it out, and the servo is fine after the operation. How it kept working with a screw loose among its internals without shorting anything, I still don’t know.

Without a manual

Spooder has no assembly manual. It’s my iteration over Aecert’s Hexapod V1, and what I went on was my memory of building the first leg in 2024, a design thought out well enough to show me most of the way and, after a while, repetition. The order of operations I learned by getting it wrong. Every joint is a servo turning a metal horn, the arm screwed onto its output shaft, and the horn has to go on while the servo is centred, in the middle of its travel, or the joint starts from the wrong angle. Usually I forgot to centre it first, and the horn had to come off again.

The day stopped on a bag of screws: Spooder takes more M3×12 countersunk screws than I had in the house, so the remaining legs wait for the delivery, and so does finding out what the virtual robot didn’t catch. The screw in the servo was a start.