That seems to be the design philosophy of the VEX guys. I promise (well, a weak promise) that I won't waste more time bitching about their horrible "close source" design decisions. But someone has to say something. Of course I used their stuff to prototype my project since I had bought 5 or 6 kits with the hope of actually using them for the final project. Now, to be fair, their nuts and screws are first rate and I have no complaints, as well as their cute chain transports if you use their square shafts of course, but the rest...
It was obvious pretty soon that the electronic/hardware side would not work due to their very flimsy nature and weak linkage (or lack of it). Take their servo for example. Not only is it far from standard, so that you cannot mix with any other brand, but it lacks fundamental elements like a horn or attachment plate of some sort so that you can drive something more than their absurd square shafts. Guess what, you cannot even screw anything to it, you can only use their "clutch" (the small cylinder with a short square stub) to attach another square shaft to drive any square holed device! BTW the clutch and therefore anything attached to it, will simply fall off if you turn it upside down. Am I missing a screw here?
You cannot see it in this next picture, but those arms or extensions that I need to drive the limbs of the marionette with have as much strength and stability as an apple stuck on the tip of a drinking straw and balanced on the edge of a glass, can you picture that? perhaps David Copperfield could use such a trick. The main reason being that as I explained, the servos connect to anything else through the wimpy clutch mechanism that cannot stand any side pressure, only direct transmission to a wheel at the most.
To be fair, after a great deal of literally hacking away with a saw, drilling and cutting and bending, I was able to put together a somewhat functional scaffolding for the stage. If I had the money I would simply make everything from scratch out of aluminum and some steel pieces. And, yes, chuck those servos away. I opened one to convert it, I was so shocked by the poor craftsmanship inside, probably built on a Chinese sweatshop (badly soldered by hand), that I just closed it and proceeded to order a set of excellent Hi-Tech servos.