> -----Original Message----- > From: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson > Sent: Thursday, January 08, 2009 11:19 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] GPSDO time constant > > Poul-Henning Kamp skrev: > > In message <4965e869.4090...@rubidium.dyndns.org>, Magnus > Danielson writes: > > > >> Ericsson created a rack system in which the bottom of the rack was > >> actually forming a closed container with the floor. > > > > We had that at one place I worked, except it was two small > "dogs" you > > attached front and back a standard 19" rack. > > I never seen it myself, so you have more correct info. I go > back from something told to me way back in time, so details > got a bit fuzzy. > > > Trouble was that you had to wash the floor first, or the dust would > > blow all over the place. > > You also have some rather high requirements on the floor > quality, it needs to be fairly flat as well. > When I worked in the special effects business, we used to use these all the time to move heavy stuff around. It actually doesn't require a "real flat" floor (1 cm grooves aren't a big issue). Think about them as small hovercraft. It also doesn't take much air pressure to lift things (large area * small pressure). For instance, folks build small hovercraft using electric leaf blowers as the pressurization fan to support a disk some 1.2m in diameter which will easily support a couple people.
The lift pads we used were about 30cm in diameter. 1 psi (7kPa) lifts about 50kg. Moving around 1 ton things with 4 pads wasn't unusual. The rougher the floor, the more airflow you need. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
