Yesterday's work at the Nautilus Drydocks

[bob the builder]

The DK Type VII is getting into the test tank (aka "pool") today.

Note to everyone building their cylinders. Check, check and double-check everything before you put it in the boat. Submerge and leak-check with the unit out of the boat. Case in point, I was checking the cylinder yesterday and when I blew into the antenna / pressure hose, I had an eruption of air coming from the rear bulkhead. Turns out that I neglected to plug an unused linkage seal opening during construction. Fortunately, blowing into the hose pressures up the cylinder and no water got in. It would have been a tragedy if I'd have stuffed that in the boat and went about trimming. It would have gradually got more and more stern-heavy as water filled the aft compartment, and I'd have been left scratching my head at why I couldn't get the damned trim right.

Aside from leak-testing the cylinder, I also spent some time assembling the prototype pieces for the 571 Nautilus in 72nd scale. Man.. it's bigger than I'd envisioned in my brain.








I also started working on a personal project that I've always wanted to tackle. It will be a massive engineering challenge to get it functional, but I need to try!. Can anyone guess what it will be?:

[crueby]

That last shot, the bow of the sub from League of Extraordinary Gentleman movie?

[skipjack]

yep, what he said!
Nautilus from League of Extraordinary Gentlemen

[QuarterMaster]

The DK Type VII is getting into the test tank (aka "pool") today.

Note to everyone building their cylinders. Check, check and double-check everything before you put it in the boat. Submerge and leak-check with the unit out of the boat. Case in point, I was checking the cylinder yesterday and when I blew into the antenna / pressure hose, I had an eruption of air coming from the rear bulkhead. Turns out that I neglected to plug an unused linkage seal opening during construction. Fortunately, blowing into the hose pressures up the cylinder and no water got in. It would have been a tragedy if I'd have stuffed that in the boat and went about trimming. It would have gradually got more and more stern-heavy as water filled the aft compartment, and I'd have been left scratching my head at why I couldn't get the damned trim right.

Aside from leak-testing the cylinder, I also spent some time assembling the prototype pieces for the 571 Nautilus in 72nd scale. Man.. it's bigger than I'd envisioned in my brain.

That stern looks good Bob! Reeeeeeeal good!

I also started working on a personal project that I've always wanted to tackle. It will be a massive engineering challenge to get it functional, but I need to try!. Can anyone guess what it will be?:

If you get her "Archimedes" propulsors to work, you will have reached the Engineering status of LCDR Montgomery Scott!!

[bob_eissler]

Looks like driving the props is going to be challenge.
Quite a bit of angle for a universal. A 90 degree gear?

[bob the builder]

For those of you who joined us for my LIVE discussion on my Youtube channel last night, I let you know that I'm getting slammed with customer inquiries, emails, requests for quote and (mostly) requests for help with projects. Yesterday alone I sent out over 50 messages via email, text and my site's IM board. That took up over 2 hours in the morning alone.*

I love it, but, man.. it's cutting deep into shop time.

That said, I did get work done, I assure you. Most of it revolved around beginning the trimming process for the 1/48 DK Type VII. What I discovered was that the 12" tank was WAY too large. I determined that I needed about half of that to float this boat, owing to the exceptionally light layup of the upper hull and detail pieces mounted to it. The beauty of the MSD is that adjusting the size of ballast tank, motor and battery compartments is exceptionally easy. The whole process of cutting it down took less than 10 minutes.*

I also performed a linkage update to the ballast servo. I've found from time to time in the past that the linkage comes off the slotted servo horn, requiring surgery to re-attach. The new MSD design allows ample room to put a full clevis on there, eliminating the possibility of it ever coming off.*





Logan and I completed final trimming of the Batsub and did a quick weathering job on the hull. We also added a bright yellow strip along the centerline, which really helps with visibility and also helps to mimic the "Batman" colors of gray, black and yellow.*

The true maiden voyage will be this afternoon with a night run this evening. I should be able to have the video up by the end of the weekend.




The LXG Nautilus is coming along well, too. The files that I'm using were not, in any way, optimized for RC. The entire interior is full of plastic channels and blocks. I've had to manually hog everything out as I go, but it's turning out well. The detail is really good. The 6th hull section is on the printer right now, and the upper hull part of it has failed, but I'm going to let it run to finish out the bottom and just re-print the top next.

Like you guys said, the drive is going to be a challenge. My thoughts at the moment, until I get the rear section printed and see precisely what I have to work with, is to run a pair of smallish brushless motors in the wet. The Archimedes screws will likely be sacrificed in favor of pumpjets, though it would be cool to mount them somehow so that they spin in the jetstream!

[bob the builder]

More shipments yesterday AM. Waiting on a big box of cylinders from His Majesty, electronics from the UK, brass props from Germany, brass from CZ, kits from California. COVID has screwed up delivery times and put a strain on delivery times, for sure, but we're keeping our heads above water!

Most of yesterday spent finalizing the mods to the MSD for the 48th Type VII and getting her dialed in perfectly for trim. This boat will forego the full static dive ability in favor of a dynamic setup for simplicity, reliability and safety. It is ballasted slightly positive. The pump circuit is a closed loop with no internal access to the dry compartments, unlike the full static version which draws air from the electronics compartment to blow ballast.*




Batsub got a brand new battery due to Logan leaving the electronic switch plugged in for a couple of days. It draws a bit of juice to stay "awake", enough that it depleted the already low battery enough that my smart charger declared it DOA when we tried to charge it up. Final pool operation and video above and below water will take place this morning with a night run tonight or tomorrow.*



Nearing completion of printing of the 1/250 LXG sub. Assembly is going well and there is sufficient room in the stern for electronics and drive components if I get creative. One of the first printing flubs on my Dremel printer in a loooong time. It wasn't the printer's fault, but an error in the file that I discovered post-mortem. I elected to continue the print despite the failure of the upper hull. Lost some filament, but saved about 10hrs of print time doing so. Final stern hull section is on the printer now, then it's just control surfaces and conning tower and she'll be ready for final assembly.*

[bob the builder]

A lazyish weekend, at least from a build perspective. Did work around the house. Lots of storms here over the weekend, so we couldn't get the Batsub into the pool for final testing and beauty shots. Hoping to do so later today if the weather holds.

Most of the work revolved around the LXG Nautilus. I completed the printing and did final assembly, filling, sanding and primer. I'm pretty satisfied with how the hull went together. I still have some gaps to fill that the primer brought to light, but that should be a quick process.*

I've been putting some thoughts together in regard to the control system for the boat. The access to the rear section is only about 1.5" wide. I'm thinking of building a clear acrylic box that will house the battery, air pump, receiver and four servos (rudder, rear planes, front planes and ballast). The ESC and brushless motor will live in the wet. This waterproof box will drop in from the top and seal on a foam seal at the bottom. In that way, if there is a leak at the main seal, air pressure will stop the water from advancing more than a tiny bit into the electronics compartment (think diving bell).*

Also thinking about the propulsion more. Those twin pinecones low in the hull aren't going to do anything, and rigging up twin props in a cramped space, while possible, isn't anything I want to play with if I don't have to. What I'm going to do is open up the rear of the hull and put a 30mm(ish) diameter hole in there directly in front of the really cool triple-rudder arrangement. A single direct-drive three-bladed prop will be mounted in a closed tube, drawing water from the interior of the hull and expelling it directly out the back of the boat and over the rudders. This has many advantages including simplified driveline, a stock-ish appearance, and superb rudder control thanks to the water flow going directly over the rudders at any hint of throttle.*









I'm also working on a new locking system for use with the upcoming LA class 3D files. This is a bayonet system designed by Randy up in Canada (the original artist that did up the files). It works really well and the test-print below makes for a solid union with perfect alignment. These were printed in draft quality so ignore the nasty seam that was printed without supports.*