It’s been a while since we last posted an update, but a lot has been happening! First and foremost, we’ve started a new venture to open a laser-cutting shop. Frustrated with long lead-times and archaic quoting processes for custom laser-cut metal parts, we decided to open our own shop and do it right!
We are a few weeks away from having a machine installed and operating, but once we have it, we’ll be able to iterate on new simulator versions in days, instead of months!
In the mean-time, we’ve revisited the simulator design in hopes of optimizing the system. The large version 2 frame allows for a lot of motion freedom, and it is sized to allow for continuous rotation on every single axis. Unfortunately, our drive system design had some issues, and we reverted back to the linear actuator drive solution instead. So the frame worked out to be far larger than it needed to be, to allow for the rotation it was capable of achieving.
We’ll revisit the continuous rotation idea again down the road, when we’ve figured out our custom motor design for a direct drive solution.
In the mean-time, we’ve shifted gears to produce a lighter, more compact, transportable system. Rotation freedom will be reduced a little bit, but the lower cost, ease of assembly, and reduced size will be nice.
The basic idea is to use a crank-rocker (a type of four-bar linkage) to rotate the chair. The crank rocker assembly directly replaces the linear actuators. This design allows for less rotation freedom (+/- 20 to 30 degrees instead of +/- 50 degrees on the version 2 frame), but it is much more compact and easy to assemble.
We may also move the center of rotation away from the head and closer to the center of mass of the assembly. In VR, rotation around the head is ideal for reasons that we’ve discussed before. But rotating around the head takes a lot more torque, which increases complexity and cost. Other commercial simulators avoid that cost and complexity altogether by rotating the base of the chair. While that’s incredibly easy to do in comparison, it is also the worst possible solution for VR immersion, because it whips the user’s head around during motion. You don’t even know how bad it is until you try it, and compare it with our system…
We think that there is probably a middle-ground. Rotating around a point slightly lower than the head, but far above the base of the chair, may simplify the design significantly without breaking immersion. So we’ll be giving that a try on this next variant.
The design is a work-in-progress, but it’s moving along!