> > There was much discussion of groupware. Steve recommended >TWiki and UseModWiki. (http://twiki.org/, http://www.usemod.com/cgi- >bin/wiki.pl). Michael mentioned MS Exchange server, of which he has a >copy. Members who do not have Windows could use Ximian Evolution >with the Exchange connector. Dave M has been playing with >phpGroupware. This matter is still under evaluation.
I sincerely doubt that there is any benefit to be had from groupware over just a mailing list at this level of activity. >POGO >---- >Dave M The basic design has been approved. Parts are being sourced. >The team's preliminary estimate is that the vehicle will come within 2 kg >of meeting its mass budget. Currently, the primary concern is throttling >valves: the ones on hand actuate too slowly. Alternates are being sought. The KZCO valves are far and away the fastest DC valves I have found, at 1.2 seconds full open to full close for the small actuator. Their actuator for 1" valves is faster, at 0.8 seconds, but it is quite large. It is worth noting that flow doesn't actually begin at the 0% position, and the last range of travel has negligible impact, so the relevant opening time is actually somewhat faster than the full scale time. If you need them to go faster, you can crank up the voltage. We ran one of our valves at 24v for a while, and it didn't seem to hurt it, and it made it considerably quicker. The various NOS solenoids are in the tens of msec actuation time, although it may still take 80+ msec to get thrust out of an engine after the solenoid signal has been sent. Dan at XCOR mentioned that they are using some pneumatic ball valves that they can bang open in 40 (!!!) msec, but you don't get any proportional control like that. You can always just adopt the same configuration we have, with a slowly throttling lift engine, and rapid solenoid attitude control... John Carmack _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
