JS had the same response. So let's take this fun, and important*, engineering exercise one more rev.
On 2010-08-23, at 3:21 AM, Morgan Sutherland wrote:
Hello Xin Wei,(1) This will not leak with some probability estimate;(2) When it leaks (and it will one day, from any number of places), the water will be contained or diverted from the electrical equipment, and the electrical cables in the room.Chance of leaking is low due to low pressure and time-tested plumbing equipment. Formula for estimate:P(Leak) = P(HumanError)
Therefore it will leak with P = 1.
We must assume that the system will leak (over the expected lifetime of the TML at least, and for good citizenship, of the EV building), and engineer a plan accommodating that eventuality. We must assume that the leak will happen when no one is around, and that it will leak when there is maximum water in the system (tank + pipes + bins), and when there are live power cables snaking over the floor because some student who never met you or any PLSS person years from now is rushing to finish an installation is jury-rigging power bc s/he blew some circuits on the wall far from the cistern, ...
You get the picture. My point is that infrastructure design (and yes, PLSS is an exercise in infrastructure design, for me) impacts those who will come after you, so you have to be concerned with people who will now know what you did or why, and who WILL do things that you do not approve, or even expect.
My raked floor idea may seem pie-in-the-sky, but on second thought, it may be feasible and easy. Just spit-balling here -- for example, when we put the boat back up, we could maybe place it over some board inclined toward the window, along which we'll place some catchment (or absorbent, not too flammable, material that also looks good and will not harbor pests). An aesthetic solution could be to place it over the "piano" table -- if we trust the table to do double duty, and have a way to failsafe the table.
Thinking further on the aesthetics -- maybe we could weave light sculptures into the boat or its rigging. Imagine phosphorescent or flourescent fabric "tendrils" twined with twine and pea tendrils.
The rolling carts, I hope, are engineered against accidents. The rubber material and its seals should be guaranteed by Toby to last say double the expected tenure of TML in that room. I.e. I would like a guarantee of 10 years :)
Xin Wei
Our version Long Now thinking will differ from utopianism in being concerned both with distant vision as well as the interim nitty gritty.
(3) The same for the "boat" which I absolutely adore and wish to see flying on and on. Assuming that the twine will break (and it will one day), what is the system for keeping the dirt from flying all over the place?Due to massive bean death and spatial concerns, the 'boat' has been dropped to the floor for now. It may be resurrected in the future, but in a new form – reinforced++.All piping is far from equipment and everything will terminate in a drip valve. The worst case scenario is a small puddle.
Where and how large will the puddle be if the full tank empties ?
On Mon, Aug 23, 2010 at 6:09 AM, Sha Xin Wei <shaxinwei@gmail.com> wrote:Hi Guys,Thanks -- You can't imagine how pleased I am to hear this! I'm very eager to see the results.Can you please let me know how:(1) This will not leak with some probability estimate;(2) When it leaks (and it will one day, from any number of places), the water will be contained or diverted from the electrical equipment, and the electrical cables in the room.From far away, I don't see a solution to (2), so that worries me. I hope you figure this out :)(3) The same for the "boat" which I absolutely adore and wish to see flying on and on. Assuming that the twine will break (and it will one day), what is the system for keeping the dirt from flying all over the place?My solution to (3) is to run aircraft cable as a second set of wires intertwined with the twine.Good engineering: building systems with over-strength+capacity proportionate not to need but to the damage that would ensue in case of failure.Thanks,Xin WeiPS. Toby, I'm sorry I missed the group! I was unavoidably elsewhere; the week before the start of the IL Y A production run has been incredibly intense. I am now back in SF for the next 10 hours, but will be again down the peninsula... read on!On 2010-08-23, at 1:19 AM, Morgan Sutherland wrote:
Quick status update:- We've received all of the actuators we need to make the automatic watering system. I'm in the lab controlling the solenoid valves with Max.- Laura and I went shopping today and bought what we thought were the proper adapters so that we can start taking water from the cistern, but we made a mistake in measuring the outlet, so we will need to go back and buy another adapter. The system is roughly this: [Cistern] --> [adapter to 1"] --(black tube)--> [master shut-off valve] --> [flow limiter] --> [adapter to 1/4"]. Once we have the last piece, will be able to fill the cistern and sketch the system with drip valves! Next step is to figure out how to jack water from next door and pipe it through a hose to the cistern (it may require removing the faucet).- RepRap parts were shipped this week.