What's the 401? Well, the best way to answer that is to see it moving — check out the YouTube video to the right, or take a look at the high quality version under 'media'. It looks a lot like the 301, but its capabilities are far in advance — because, for simulating a vehicle, its rotation is incredibly important.
You probably know, intuitively, that when you're driving a car that's sliding all over, it's the rotation that tells you when things have gone wrong. Research in this area generally says that physical sensations take the lead over your eyes by about a tenth of a second when you need to react to something like a car sliding — and without feeling this rotation axis you rely on your eyes (or, in the 301, the secondary sensation of lost lateral grip) to tell you what's happening.
The standard 401 gives you plus or minus 90 degrees of yaw, enough to provide excellent cuing: A rotation ratio of roughly 50%, and washout times of around five seconds — as opposed to less than a second for washout with most 6DOF platforms.
The 401cr goes further, with the ability to rotate forever without 'winding up'. Essentially, it can do two things no other simulator can: It can provide a perfect one-to-one ratio between vehicle rotation and simulator rotation, and it can do so without washouts or any inverse forces.
While long, difficult-to-feel rotations can be 'washed out' in a limited-rotation simulator (and washed out more effectively in a large-rotation simulator like the standard 401), washouts mean changes of direction — and changes of direction can be felt. The lower the rotation range, the worse the problem is. When you feel nothing during a long corner in the 401cr, you're feeling nothing when you're supposed to be feeling nothing.Feeling something when you should feel nothing is the only thing worse than feeling nothing when you should feel something.
The 401cr can give you exactly — and only — what you're expecting, leaving you free to drive instead of translating the simulator's cues.
So, this is great! But what we found when we started testing the 401 is this: Not only is it important to feel the rotation of the car when you've broken the rear end loose, or in a four-wheel drift, but it makes an incredible difference even when the car's glued down to the road. The ability to feel the rotation of the car through the corner means you know where you are in space; that sense of turning tells you even more than your eyes how close you are to the apex.
I have a tendency to apex too early in the 301; even more so when driving a desk. The feeling of positioning left-right on the road with the standard 401 is vastly improved — and with the 401cr, it's downright uncanny.
The rotation axis actually gives you a physical sensation of position on the road, something we didn't anticipate when we started out.
We haven't heard other people talk about this, and we think this has to do, again, with the large rotation range provided by the 401 and 401cr. The ability to accurately replicate long, medium-speed turn-ins, and in particular the turn-in leading up to the apex, requires a very large rotation range, something that standard 6DOF platforms can't provide. We think this feel for positioning is essential to fine car control, and for training and serious simulation, we're confident this puts the 401 series head and shoulders above other platforms.
So, take a look at the video. Read up on the specs, and find out about the 301 (the 401 has all of its capabilities in addition to the rotation axis). If you're interested, give us a call and come try it for yourself: pictures are good, and videos are better, but there's nothing like actually driving it.