With a slight cantilevered cavity at the base, instrumental as a *nut cracker… o:)) * = time?
> Le 9 sept. 2021 à 18:35, Dana Whitlow <[email protected]> a écrit : > > One might also consider mounting smaller items inside the cylinders of the > engine block, > to get the most out of its thermal mass. > > Dana > > > On Thu, Sep 9, 2021 at 11:03 AM Joseph Gwinn <[email protected]> wrote: > >> On Thu, 09 Sep 2021 03:30:35 -0400, [email protected] >> wrote: >> Re: time-nuts Digest, Vol 209, Issue 6 >> >> >>> ------------------------------ >>>> Date: Wed, 8 Sep 2021 18:54:03 -0700 >>> From: Tom Van Baak <[email protected]> >>> Subject: [time-nuts] in-ground clock room >>> To: Discussion of precise time and frequency measurement >>> <[email protected]> >>> Message-ID: <[email protected]> >>> Content-Type: text/plain; charset=utf-8; format=flowed >>> >>> I am considering a below ground "clock room" away from the house. This >>> will be for some low-drift quartz oscillators and also a couple of >>> precision pendulum clocks. The goal is long-term, unattended, and very >>> undisturbed operation. >>> >>> For scale, assume the room is 1 meter × 1 meter × 2 meters deep. So >>> that's vastly smaller than digging a basement, but much larger than >>> drilling a 8 inch round pipe. Digging down gives some natural isolation >>> and temperature regulation. A couple tons of concrete gives high >>> stability vertical walls for the pendulum clocks. >>> >>> If any of you have personal or professional experience with the design >>> or construction of this sort of thing, especially experience with >>> precast (utility) vaults or poured concrete, please let me know. >>> >>> In case this gets too off-topic for time-nuts, off-list email to me is >>> fine ([email protected]). >> >> As others have said, it may not be economically practical to build an >> underground clock room. >> >> Assuming that you have a basement of other suitable room in your >> house, I'd suggest an insulated box or room containing a big lump of >> iron riding on an inner-tube suspension of some kind. The big lump >> of iron can be a 500-pound truck engine head or block from a >> junkyard, steam cleaned (to remove oil) and painted (to keep the rust >> under control). Drill and tap holes as needed for mounting. >> >> This box/room plus block can be set up as a temperature-controlled >> oven with a few extra components, including a PID controller. >> >> Bolt a thick plywood floor to the top of the iron hunk, and attach >> the clocks to this floor. >> >> Joe Gwinn >> _______________________________________________ >> time-nuts mailing list -- [email protected] -- To unsubscribe send >> an email to [email protected] >> To unsubscribe, go to and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
