Bringing 1/128 Seaview back to the pond!

[salmon]

Running the air hoses for the SAS system.
On my Gato, I made a holder for 3/32" aluminum tubes that brought air to and from the pump.


So, I already had the mold and as it was, I cast periscopes for my Gato and this part is in the same mold. The resin I used is for a different project I am working on and whenever there is extra resin I cast extra parts. Now I did not have 3/32" Aluminum tubes or 1/8". I din not have any brass tube in 3/32", but I did have 1/8". I cut out two tubes the length I needed and drilled out the holes to fit 1/8".


Cleaned up the flash on the parts and sanded the base of these tube holders against a length of tube the same diameter of the Sub-Driver.


For the meantime, I will not affix these to the WTC tube. I need to see if I like the fact the tubes cross over the vent.


Since these tubes are 1/8" and not the 3/32" it is a little tougher to get the hose connected. Tougher not impossible. I used a scratch awl to widen the end and a flame to warm up the hose. Then relatively quickly push the end over the tube.


It still is a challenge, but persistence paid off.


Time to install the Sub-Driver into the sub and test servo movement and see how the push rods worked out.



The magnet is placed against the deck towards the bow. A vent hole happens to be a perfect locator for where the switch is underneath.

[salmon]

Testing the rudder:


YES! It worked.

Bow planes:


I think that works.

Now the Sail planes.


Two out of three is not bad. This will be a reasonably easy fix.

[bob_eissler]

Nice Job! My bow planes have never worked very well, way too flexy. Most people didn't try to make them work.

[salmon]

Bob,
There is a little slop in the movement that I need to look at. It seems the travel distance is good, but I can wiggle the planes. It will be nteresting to see what happens in the water.

[salmon]

Played more with the sail dive planes and I found the issue with travel. It was interference from the air hoses. When they get permanently mounted and extra trimmed off, there may still be a little more reshaping of the push rod to not bind as it moves forward and backwards. What little I did gave me full throw both ways!

I guess-timated the amount of weight the sub would need and placed it where I thought it would be needed (right below ballast tank) and some towards the bow. Made sure the Sub-Driver was sealed and ready to be tested.

Placed the sub in the water and the aft immediately sank. Lifting to see how much it resisted I could tell I need some bigger chunks of foam. I trim my subs in the submerged state first and then surface trim. Flooded the ballast tank by tipping the sub over to make sure all the air was out. The sub settled to the bottom of the tub. Definitely do not need more weight. So I added a chunk of foam on each side of the Cadillac wings aft. That brought the aft up, but the bow was still heavy. So, I placed one block a lot smaller in size (lifting the bow, it moved relatively easy) under the bow of the sub. The large foam blocks in the back were trimmed down in size until the boat leveled out and the front block I cut in half so a piece can be on either side.


Some fine tuning was done to the front and back foam until it settled lower in the water to this point.


That looked great to me.

Now emptied the ballast tank to see where the boat sat.


I was surprised how much it raised up to. Again, it looked good, but I was not sure if the bow was to be higher out of the water. As it is, the waterline went to the top of the windows.


Moving the foam to below the waterline it lifted the front to where the water was about the middle of the front windows.



Time to take out the sub and record the locations of here the foam is.


We will have to trim again because those large blocks in the aft end, will not just fit into the inside. I will need to shape and install the foam trying to distribute the foam's mass to give the same lift as it does as one chunk. I will try to explain that when I install the foam and document it (please let me know if I am making it clear as mud or not).
Looking at the foam in the front, I might be able to remove another weight out of the sub and forgo most of this foam. I will test that in the next couple of days.
So here is the weight from the original install that I did not put back in.


Until next time.....

[salmon]

There are a couple of ares that came up from the water test.
1. When venting the ballast tank, it seemed to go very slow.
2. I wired my motors wrong.

The vent was a very simple fix. There are 2 wheel collars on the vent servo pushrod. I moved the collars further away from the servo about 1/8". Tested it in the tub and the tank emptied in seconds. However, when the vent was closed it leaked (like a bubble every second or two). To correct this I moved the collars back towards the ballast tank servo a smidgeon. That was just enough to stop the trickle of bubbles.

Tonight or tomorrow, I will get the motors rewired. Also begin the re-testing of trim with another chunk of lead removed.

[salmon]

I did not get to trimming. There were other areas nagging me. I wired the motors like my Gato one turned one direction and the other opposite direction. However, When I tested the forward and reverse thrust, one side pushed and the other, well didn't. Turns out, the props are both right hand turning props (verifies with Mr. Merriman). The motors got rewired.

The sail plane is a odd heavy plane. It flops around and it just annoyed me. I also wondered if it got bumped while running it would flop in such a way that it would get lost from the magnetic connector. To stop the flop, I put a piece of plastic in to prevent the rotation.


That seemed to work.


Another concern was something mentioned by Bob Eissler about volume of air being taken up by the batteries. I moved the SAS air intake valve up higher. Hopefully it will break the surface and open up before exhausting the available air in the cylinder. Just an extra margin of safety (or that is what I keep telling myself). If it works, it was a good idea. If not, well it will go down as another dumb idea.
So, to accomplish this idea, I put a smaller rod into the existing intake air tube and that smaller tube joined another tube that matched the existing air line in diameter (1/8"). Now you might be wondering why I did not take the existing tube out and just replace with a newer longer one. The answer is two fold. First, the tube was securely glued in and I probably could have gotten it out, but it would have destroyed the tube and that leads into the second reason. I did not have any longer pieces of 1/8" brass tube (I used the 1/8" on the WTC air tubes on top of the WTC).


Raising this were the top of the valve touched the top of the sail inside.


Now to secure this to the base made earlier, I cut two more plastic squares and drilled a 1/8" hole in the center. The two squares were bonded together. This was enough of a support to keep the extension from moving around. I used RTV silicon to secure the tube to the new plastic base and secure the new base to the original.


Spacers are installed until it all cures.

[salmon]

The air tubes needed to get affixed to the Sub-Driver tube.
Once I decided the placement, I put painters tape outlining the base of the tube holders.


Then moving the tube holder away, roughed up the cylinder's tube with a course sandpaper. The tape protects the tube so only the area beneath the holder will get roughened up.


Dabbed on some RTV silicon and placed the tube holder back into the location blocked out by the tape.


I used masking tape to hold the tubes and tube holder down.


Carefully removed the painters tape. This then took the extra RTV, that may have oozed out, away before it set. Extra masking tape was place to keep everything secure until fully cured.


I will call this done for today. Maybe tomorrow will be a day of cutting foam and playing with trim. I want to see if I can forgo the front foam by removing the one weight removed.

[salmon]

The large blocks that need to go in the aft area need to be shaped and installed. The blocks cannot just be put in here because we have Push rods, drive shafts, and curved walls need to be taken into account.
So shaping begins.


The inside face of the foam that fits next to the cylinder needs to get a curve too.


Everything gets tested and shaped.


One I was happy, yeah my bar is set low, I placed RTV rubber on. Why am I doing vertical lines? Well, there is a story to that answer. My Gato when first put in water after not being wet will set higher. After being in the water it will slowly settle down. When I was building it, I had strange things happen. One moment it was trimmed well and the next it was heavy. I came with the theory that I have areas trapped behind the foam that slowly release the air trapped there. To test this thought. I put the Gato in the kiddie pool and filled the ballast tank. After a time, I do not remember how long, let's say an hour. I came back out to find the sub sitting on the bottom of the kiddie pool.
Now back to the vertical stripes. My thinking is any air will be able to travel out and not be trapped by any horizontal rubber sealing or slowing air from escaping.

With all the trimming and shaping, I am losing some of that foam. This is some of the bits and pieces trimmed off.

Stacking it helps me work on guesstimating how much more I need to add to make up for what was lost during shaping.
t

Another point about trimming and adding of foam (and weight for that matter). Location makes a difference. Let us say my aft is heavy. If I put 1" cube at the very end of the sub and for discussion sake, that made the trim perfect, if I move the foam inwards say 4", the sub will become heavy in the aft. The opposite is true too. If I put a foam that is 12" from the aft of the boat and the boat is level, if I move the foam further back the aft end will begin to rise. So, I mention this because the chunk of foam I used, I need to try distribute it to match the one piece lift that is now spread over a larger area.

[bob_eissler]

Lifting the float up is a great idea, has to help. I think I have had foam trap air too.

[salmon]

Did some testing on Monday (got sick yesterday - sorry for not posting sooner).

Moving the float up higher did indeed help!
Had to add weight back in. The sub on surfacing has the tendency to roll (like the Gato does) as the ballast tank is emptying because of the large amount of freeboard we are hoisting into the air. Once empty or surface trim it sat fine and fully submerged it was fine, it is just that transition. The way I reduced the roll in the Gato was to add weight and offset it with more foam (increase metacentric height).

I will post photos and more info as I will test again tonight.

[salmon]

There was just a little bit of foam needed to get it level.

I thought great I'm done, but bringing it to the surface i dipped to the side almost looking like it was going to roll over!
I have seen this before.

The Gato sub was a great learning sub for me. This sub has a similar quality, we are moving a lot above the surface of the water and it is a narrow sub. What I learned was you need to add more weight and more foam to over come the tipping or reduce it significantly. I put just one of the weights in, the largest one of the three and went back to trimming.

Several chunks of foam and when it was level, the sail was higher than I wanted. Added a little more weight. The weight was put just behind the sail, but let me show how position can make a big difference in trim. I took a small weight and moved it aft.

Looking at the sail, you can see just how tail heavy it is now.


Now moving that same weight closer to the sail it changes the trim.

The tale of the sail shows a much closer to level trim.


I know the bow area has plenty of room for the foam so minimal loss of foam to make it fit. The aft area is a bit more challenging and you do your best to arrange it and trim it to fit. Once it was all installed, another day and it is time to see where we are at.

Placing the sub in the water the aft was still heavy. Two more blocks are added and attached.

Another day to let the RTV to setup and we will see where we are at.

[salmon]

Back to the tub, the gremlins keep showing up. The entire sub sank. It sits great on the surface. More foam, but more in the center for lift. Maybe a slight bit aft heavy and certainly lower than I wanted.


Added two small blocks to lift it higher in the water and just a bit to lift the rear up.




That leveled it out and I like the height it sits at.


Since I was affixing the foam under the deck, I wanted to make sure air can travel. I suspect some of the variance I am seeing is air trapped. Filed a channel that should work at directing air.

[salmon]

Tested and I think we are ready for the pond!


A brief video.

https://youtu.be/lF-MrFuVll0

[salmon]

A little work before I take the Seaview to the pond this weekend.
I moved one of the straps to the front of the WTC. Originally both were towards the aft and I liked it better being held in place on the extreme ends.


I went ahead and made my own radar for the Seaview.


Now it is fairly delicate (powder type 3D printer) and was post processed with a thin CA glue, but to kick it up a notch, I soaked in Marine grade epoxy.

The extras are for the times I break them (I have a gift of doing that). Maybe I will never need them, but if I do.....
Once the epoxy dries, I will lightly sand the surface to smooth out the sandstone type finish and paint on a flat clear coat.