John Carmack, I was wandering if you folks had any concerns about the deep enclosure around the jet vanes? It seems to me it may cause some problems with the gas dynamics for controlling the thrust vectoring. It seems that as the vanes deflect a significant amount the gases are going to impinge on the side of the box and basically have the steering effects basically canceled out. Also it would seem that at extreme vane deflection the back pressure behind and to the side of the vane and the box could be the cause of the stress failures of the shaft and vane that might not of other wise have happened in such a constricted volume.
Have you considered instead of the shielding box, instead covering the bearing and servo motor with a low profile as possible high temperature flexible thermal insulation blanket, perhaps made of fiberglass or nominex? Also perhaps the servos could be moved further up and away from the exhaust backwash by coupling them the the vane shaft by a universal joint and thus moving the servos up and way, say up to 60 degrees. I know that the system is now an experimental steeping stone to your next vehicle, and thus your trying to keep it as simple as possible. The landing gear looks to have a very narrow foot print and only a modest amount of sideways motion on touchdown would result in the vehicle toppling over. Have you considered for at least the first free flights putting 'training' struts out on the landing structure? I know its probably going to be a while but when you plan on having the vehicle going to higher speeds and altitude, have you considered putting a angled down facing camera with a RF link? The idea is that if the vehicle encounters control problems or unexpected drift and possibly has to land out of direct view of the ground control station, such as having to land it on the other side of a hill or tree. This would make possible last minute adjustment to avoid undesirable landing locations that the auto land code would have no way of knowing about. Also along those lines any thoughts about some sort of close range terrain sensors such as a IR or ultra sonic ranger. I know you have a GPS system but it can't take into account the odd little topography issues if you have to land further away from your takeoff point. Just some thoughts, from my own experience in technology developments I empathize with you on the frustrations and joys of such an effort. - Edward Rupp _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
