So i had to stop working on the printer for a while, as all of my spare time had evaporated.
So My Friend who i work with at my day job is a contract Mech Eng, he starts sending me lots of SMS's messages asking if i have any spare time that i could help him with a project, he got him self a contract on the side as we had nothing for him really to do. so as i was approaching the office i tell him that i am 2mins away, and he keeps sending me more sms's asking more questions. so i finally arrive in the office and we gets talking, he explains that he cant tell me a lot as he is under a NDA, as i kept asking questions he relented and took me to the factory, where i immediately signed a NDA so i could find out more of what was required of me..
As I walked into the factory area i see this great big mass of fiberglass and steel, and i turn to dave and say that looks a bit like a submarine! he then proceeds to tell me that its going to go to the very bottom of the ocean. the Mariana Trench.
Dave then took me around the factory and showed me what was what. then he started to explain what the problem was that he was getting me to help fix. The problem was that when the submarine goes to great depths like the bottom of the ocean the temps will drop to about 2'c whit the internals of the sub being about 15'c. with a human in the sphere there is a lot of condensation on all the cold surfaces. as James Cameron wants to film through the window we had to device a way to keep that window perfectly clear.
Taking what i had learned about making PCB heaters for the 3D printer i determined that the best way for us to go forward would be to place a PCB between the glass and the mounting frame, this PCB would have a single track etched onto it in a zigzag pattern in a circular pattern, this is then fed with 3.3volts, witha resulting resistance of 2.5 ohms the resulting power is about 4.5watts of heat applied to the glass in the viewing portal. this window was attached to the outer window with a sealed section of nitrogen to purge all the moisture from between the two windows.
Once powered up the Glass window gets to about 30'c in ambient open air. when installed the mounting frame takes out a bit of that heat resulting in s nice 20'c difference between the air in the sphere and the glass.. and this positive difference prevents any condensation on the viewing window.
Dave Saw how easy and quickly we had solved his demister problem and asked if i could stay on for a little while, this little while turned into a long time 14weeks!!! As soon as we solved one problem another arose elsewhere in the project and as everyone was already assigned to solving issues of their own i ended up working on a lot of very different systems. These varied from Fiber optic cabling, 3D Cameras. Making up some very top secret Penetrators that could with stand 20,000psi pressure differentials. I used a wide and varied selection of test equipment ranging from fiber optic OTDR's to Pressure chambers that could test objects upto 22,000psi (styrene foam does weird things at high pressures).
Working with James Cameron was a Great experience, He was not just simply paying the bills for this project but he actually came up with a lot of the designs and solved a lot of problems that we had run into, his ability to not only visualize and understand the problem but to be able to communicate that to the engineers and technicians was refreshing. While at time his requests may have been demanding they were not unbearable, and he is quite sane, i thought anyone that wants to go that deep in a submarine had to be a little crazy...
If anyone has any questions i am happy to try and answer them, please note there are some things that i cannot disclose due to a NDA that i am still obligated to adhere to.