Ray Mason Nautilus Build

[Davjacva]

A lot of it depends on the nominal angle you put on the pitch in "neutral". If they're aligned to the longitudinal axis of the boat, you'll get diving action under speed. If you angle them up slightly (which yours were by quite a bit), you can override that tendency. Like Dave's Seaview, a tiny bit of upward pitch will override the tendency to dive and keep you at neutral pitch under power.

Except for a couple of times during the event Thursday and Friday. I had neither planes or pitch control, but when I had them, holy smokes what a difference it made. Since I had neither, I both were in neutral, which didn't take any effort with the pitch as it just defaulted that way. This was the first time that we got to see what our efforts did as running at the pool previously was almost as bad as not running at all...and we now had a 4-blade, 5-bladed prop to boot. As a former COW/ DOOW, I wanted to see what this thing did, so I ran the snot out of it, both forward and reverse, surface and submerged. This was all straight-running with absolutely no rudder.
This was my testing:
Surface: Running forward it would run great until you gave it a flank bell, then there was fluid shift and it would run a nose-dive, and a prop-wash would start...so back down. A backing bell, had no problems at all and steerage was pretty good. After a surface trim loss after running flank, I'd start the LP blower and get back up to surface trim. Funny, this is what a real sub does surface-transiting every hour :)
Submerged: The submerged trim it turned out was slightly heavy, and this turned out to be advantageous. There were air pockets behind the 'gator eyes' and I could get rid of them, but doing a submerged backing bell which made the sub take a 45-deg dive rearward. Now with all air purged it was ready to go. I would only run rearward submerged to do this as it served no other benefit. Going forward from a dive, this was with no ability to shift planes or pitch, the sub would dive, but not fully. When you cleared the air, then the sub would dive when it had about a 1/3 bell or less. Any more thrust, and the sub would porpoise to the surface. So with a slow bell on, the sub would submerge, and you could maintain depth with speed, or surface, or just slow down and you'd sink. At a certain speed, you maintained depth perfectly. Not rocket science. It would act this way all the way to the bottom, and I could run it at depth this way, as long as I could see it (during the bright of day).
So to me, taking the simple 'planes, angle, speed' approach, it worked pretty well. I lost my rudder control three times, as the magnet on one side was repeated pulling the other out of the housing...even using JB Weld. Merriman was shocked, so suggested wiring it in place, which I did and that was that. One thing about the rudder control, we were surprised by how much response we had to the throw we had. It's not going to turn in a pool, but it sure beat Dave's Seawolf in the turning contest.
When I finally got pitch and plane control late Thursday, it was shocking how much each affected the performance of the sub. I didn't have to worry about clearing residual air...nothing. That sucker would dive like nobody's business using the pitch control only. Using the planes only, the sub would change depth noticeably. Not great, but it did. The servos were apparently a big problem. Dave thought it was something else and it just became apparent on Saturday, what the problem was.
After the fixes are to be made, won't be able to find out the theory to practice puzzle till next year. Thanks for the feedback Bob.

[Das Boot]

Are you going to New London? I hate New London, but I'll suck it up.
BTW, my e-mail is davjacva@gmail.com.
Jake

I’d love to, but it’s too far, and the wife and I are taking a train to New Orleans about April or May.

[Davjacva]

Puts some lighting in the Nautilus. Merriman put a power outlet out the front of the WTC, so I made a protection module for the LED lights. The first time around, even though I had it drawn with the resistors on the parallel side, I put them on the series side (the lights themselves were still parallel), so I was getting only half the amperage and if one light died, the other would blow. Anyway, I did the two types of circuits on a breadboard. The LED lights in parallel with the resistors on the series side are on the left of the photo, the ones with the LED's with the resistors with them in parallel are on the right. You can see the difference very well. The ones on the right have twice the current and well within spec. Both circuits have a voltage regulator, and 3 capacitors, so no matter what batter gets hooked up, the lights are protected.

[Davjacva]

The last time I ran subs with Merriman we went down to Mud Lake, I think it's really called City Park Lake. It's down in North Carolina right across the border from us. It's hosted by the 1/96 skimmer club, but this was an open event. The lake is pretty shallow and I made the mistake of diving with the Nautilus and the teeth on the bottom immediately get stuck in the mud on the bottom. Twice we thought I was going in, but it'd pop up after a few minutes. Switched over to drive the 1/96 Skipjack, and even with it's round hull it got stuck. So, diving was a PD only, or be a surface runner and test out the range check on the receiver...:} Any, through the dog and pony show of trying to launch the subs (arms length, on your belly), and all the other hoopla, we lost another blade on the Nautilus prop. So Dave said screw this and proceed to make a set out of white metal. At the same time I asked him to make me a new brass replacement blade and that I was going to use the resistance soldering unit this time, vice a flame. Well, the white metal blades needed to be filed back, so in this photo, I've filed the blades to their new shape and cleaned up all the props including the initial brass one. For photos of the work casting them and after they were painted and one mounted on the Nautilus, go to Merriman's page and it's all on page 132 to see all of that work (casting, resistance soldering, and after they were painted).

[He Who Shall Not Be Named]

The last time I ran subs with Merriman we went down to Mud Lake, I think it's really called City Park Lake. It's down in North Carolina right across the border from us. It's hosted by the 1/96 skimmer club, but this was an open event. The lake is pretty shallow and I made the mistake of diving with the Nautilus and the teeth on the bottom immediately get stuck in the mud on the bottom. Twice we thought I was going in, but it'd pop up after a few minutes. Switched over to drive the 1/96 Skipjack, and even with it's round hull it got stuck. So, diving was a PD only, or be a surface runner and test out the range check on the receiver...:} Any, through the dog and pony show of trying to launch the subs (arms length, on your belly), and all the other hoopla, we lost another blade on the Nautilus prop. So Dave said screw this and proceed to make a set out of white metal. At the same time I asked him to make me a new brass replacement blade and that I was going to use the resistance soldering unit this time, vice a flame. Well, the white metal blades needed to be filed back, so in this photo, I've filed the blades to their new shape and cleaned up all the props including the initial brass one. For photos of the work casting them and after they were painted and one mounted on the Nautilus, go to Merriman's page and it's all on page 132 to see all of that work (casting, resistance soldering, and after they were painted).

Notice that the 'new' white-metal propellers are left-handed pitch -- as per the studio drawings and full-scale propeller (seen in the 'repairing the rudder' sequence of the film) -- not right-handed as is the brass propeller I manufactured so many years ago (only those godless Commie's are into left-handed single screws on their submarines!).

Hey, Ray: I have two finished propellers sized to fit your NAUTILUS kits -- want 'em?

David

[Davjacva]

Today, I got with Merriman to address an on-going rudder issue we had on the Nautilus that started Friday while at Cohutta. We thought the issue was corrected, but it kept rearing it's ugly head and Dave had an idea to finally kill it, so today that happened. Dave made a new interface between the actuation of the servo to the rudder which incorporated a much larger magnet. The magnet was also shielded by a u-shaped piece of brass sheet. Before the rudder linkage was coming uncoupled from the magnet on the operating arm from the servo. This was very much high-lighted when running in reverse. I'm confident that this will be more than sufficient to adequately control the rudder. Still have to test it.

[Davjacva]

Part of the Nautilus's re-work following last years two events, is a partial re-paint. These were areas that the spray foam crept out and went on mostly, but some dinged areas as well. No biggie, I wrote down all the mixes and processes. After Dave had correct the issue above with the rudder control, it became apparent that the current green foam stand that I had been using since the initial build was too topsy to keep going, so a new and proper stand needed to be made that lowered the cg and was less tipsy. Did one for the SSN-591 as well.