The Binary 2
This is a craft designed to switch easily between VTOL and a standard SSTO but always having the engines and main body remain one craft, unlike many other similar designs. While this does make the craft much more complex in some ways, not having to worry about engine collisions plus the ability to lock in any location make it, in my opinion, worth it.. It is capable of getting an orange tank into orbit, but cannot VTOL with it. WARNING: Advanced Tweakables required
This craft is an improvement over my old, outdated Binary SSTO, which was based on an even older one command join prototype. The craft features an actual cargo capacity over the original, re-dockable spacers, and the ability to lock the engines not just vertically and horizontally, but anywhere in between. This craft works on the principle that the small spider engines are very very weak, and you can easily build a bend into it. This is the same as before. Like before there are to bearings that surround a decoupled spacer that restricts this flexibility to rotation of the engines only. This time however this spacer re docks easily, and the locking mechanism is much more secure.
The engines are controlled by W and S when RCS is on. To lock them in place, for long term or really any maneuvering, auto strut one of the main body parts (i use the cargo bay) to the root part (as the root is technically on the engines) and remove/change the auto strut on the same part to rotate the engines again. The engines will likely re dock to the spacer when set horizontal (this can be a little finicky, but really only matters in space). This is the ONLY time when time warp is supported, and to help with the reliability of the craft, use the auto strut trick even now. The craft can be changed at any point in time (even in flight) but do not be going over ~50 m/s while doing so The reason the craft is able to redock this (even if the engines are on) is the fact that the "spacer" has parts auto strutted to both the heaviest part (main body) and the engines (root part).
This craft took me quite a while to build, mainly because I could not find a happy medium for "soft lock" or what I eventually used the auto strut trick for. Nothing had either the speed, or strength of this, but I usually dislike making the user of the craft click things like this. (IMO a very important part of craft building, especially complex things, is to make them easy to use.) I more favor action groups due to the simplicity, but unable to find a better solution (and KSP not updating action groups in forever, even if we have more tweakables) I believe that this trick should work, as the player can pick practically any part on the craft. It is also the strongest possible soft lock that I could create.
Other than the VTOL capabilities, this craft has a very simple ascent. Due to its inherently high T/W ratio, simply point 10 degrees above the horizon until flameout, and then tilt up to around 25-30 degrees when making the rocket burn. Then simply circularize
For the Action Groups
1) Undock spacer
2) Toggle Rapiers
3) Toggle Rapier Mode
4) Toggle Cargo Bay
5) Decouple Payload
0) Deactivate spider engines (in case you press space by accident)