Yeah, I know this setup is a bit unorthodox but that elbow is a 1/4" copper plumbing fitting so it's pretty big inside (about 9/32"). With the 3/8" brass tube, there is no reduction in internal diameter until the nozzle. The large internal diameter of the discharge also means the flow through the bend and up-tube is slower and at a higher pressure. That's what you want when going into the nozzle which trades pressure for higher fluid velocity. This setup with my latest nozzle is doing better than 2GPM with a generic no-name motor. In tests it primes well but only battle testing will tell for sure. What I really like about the mounting is that the complete pump assembly (with nozzle) pops right out.
Finished up with the waterproofing. All exposed lumber gets the Titebond2 gold treatment The motor keel coolers are installed.
Started work on the brain box. I'm using 3/4" 6-32 aluminum lugs and nuts for the wiring penetrations. Threads are sealed with green Loctite. Motor and pump ESC's, Rx, and firing board will be packed in here.
Looks very neat and clean. Have you used this system before? With the heat I always plan the ESC's to be potted and placed in the bottom of the hull. My friends help me to keep it cool. With 3 of them packed in a water/air tight box, do you worry about the heat?
Done this before? Nope, it's a first for me. For heat I will be bonding an aluminum plate to the bottom with some aluminum blocks coming up inside with the ESC's attached to them (similar to the motor cooling setup). Just haven't gotten that far yet.
I make not claim at being an engineer. I am pretty good at "monkey see monkey do". I am pretty sure that the ESC's have a temp shut off. I would hate to see you dead in the water.
The h-bridge board I'm using does have a heat cutoff which works quite well (we tested them on tank motors). For heat dissipation, besides the aluminum heat sinks that will be installed, I was also contemplating filling the box with mineral oil but that just seemed so messy.
Steve, I am seeing more and more people spending more effort waterproofing the components and less effort on the waterproof box. I am moving in this direction (Monkey see Monkey do). I have seen the electrical boxes periodically in the past. They do not seem to be copied enough to give me confidence. I never seen a good way to seal the lid and still be able to do maintenance on the electronics. Very prone to leaking. We used the Otter Box for years over here to great success. (Monkey see money LIKE). I can’t find the Otter Box any more, but the GSI box is what I am currently using. http://www.backcountrygear.com/gsi-lexan-gear-box.html?gclid=COSH2Pvguc0CFQFsfgodubkCbQ . Hinged lid with a seal.
I hear you (fyi, I'm also waterproofing the individual components). The reasons I'm going down this road is that 1: I've never done a waterproof box , 2: the compact and neat installation appeals to me, and 3: it will be very resistant to bb damage and copper sulfate issues. As far as maintenance, if setup correctly, there shouldn't be much need to go into the box all that often.
We don't have the Sulfate issues here. On the other hand every body of water is a pristine salmon habitat. Your not going to put BB's in the water are you.
Cooling upgrade to the brain box. An aluminum bar is epoxied to an aluminum plate with a very thin layer of JB Weld. According to several over-clocker forums JB Weld has some decent heat transfer capability. Hole cut in the bottom of the box Plate bonded to box with E6000 Huge radiating area (especially when wet) ESC placement
Tested the watertight integrity of the brain box today. The test rig 8' down (.00244 kilometers for you metric types) After four hours, not a drop inside.
