New Los Angeles Class Build Questions

[Marylandradiosailor]

I'm starting my first build and am looking for suggestions on two items..

1) From reading it seems the real LA has a propeller speed of 150-200 rpm? I'm planning on gearing down a brushless motor, what do most folks use as a good maximum prop speed for a 1/72 scale model? I'm assuming as fast as possible isn't the right answer and scaling down 150 rpm also isn't the right answer?

2) To have a flooded outer hull I will have to have holes at the top and bottom of the hull for the water to enter/exit. The LA has some grates/grills on the top which should work but on the bottom the openings are small in number at the front and rear of the hull and I am not sure if these will be sufficient. Are these sufficient or will should some additional holes or slots be added at the bottom even though they will not be scale like?

Thanks for any assistance. Khim

[SubICman]

The flood holes that exist on the bottom are more than enough to let water in. You can model a 1/72 scale 10 inch hole about 6 scale feet behind the scopes located on the keel. That would be the trash disposal tube. Another scale 10" hole on the keel 30 scale feet behind that, representing the depth control hull valve suction/discharge. That gives you 2 more water inlets, all be it small ones.

The part that needs to be creative is disguising the top half holes within the existing features to let the air out. There are a couple areas where they make sense when compared to the real thing. Air bubbles within the hull will mess with your trim.

I am not versed in reducing brushless motors as I am still in the dark ages using brushed motors. I reduce them around 3:1, although some guys do direct drives. I will defer to the other experts here as there are many ways to skin this cat

Tim

[He Who Shall Not Be Named]

I'm starting my first build and am looking for suggestions on two items..

1) From reading it seems the real LA has a propeller speed of 150-200 rpm? I'm planning on gearing down a brushless motor, what do most folks use as a good maximum prop speed for a 1/72 scale model? I'm assuming as fast as possible isn't the right answer and scaling down 150 rpm also isn't the right answer?

2) To have a flooded outer hull I will have to have holes at the top and bottom of the hull for the water to enter/exit. The LA has some grates/grills on the top which should work but on the bottom the openings are small in number at the front and rear of the hull and I am not sure if these will be sufficient. Are these sufficient or will should some additional holes or slots be added at the bottom even though they will not be scale like?

Thanks for any assistance. Khim

[RCSubGuy]

In my experience, something like 3000 to 4000 rpm will get you what you want in terms of performance at max throttle. It will be tricky finding a low kV brushless that will work on a standard 3S LiPo. at 11.1V, you'd want something in the 360kV range. At 2S, options increase (slightly) as your kV rating is more like 540.

Gearboxes could drop your RPMs, but you increase complexity.

[Marylandradiosailor]

Thank you all for your assistance, the photo's are most helpful. I'll work out the motor and gearbox given some idea of where to start. Khim

[Marylandradiosailor]

Continuing my build modeling the San Juan .... I'm trying to get the lighting correct.

I assume there is a RED light on the port side of the sail and a GREEN light on the starboard side of the sail, are these lights under the clear covers as per the arrows ?



I assume there is a yellow light on top of the snorkle 1 flash/sec for 3 seconds then off for 3 seconds and a white stern light on top of the rudder ?

Is there a white mast head light ? located where ?

Thx for your help, Khim

[He Who Shall Not Be Named]

Continuing my build modeling the San Juan .... I'm trying to get the lighting correct.

I assume there is a RED light on the port side of the sail and a GREEN light on the starboard side of the sail, are these lights under the clear covers as per the arrows ?



I assume there is a yellow light on top of the snorkle 1 flash/sec for 3 seconds then off for 3 seconds and a white stern light on top of the rudder ?

Is there a white mast head light ? located where ?

Thx for your help, Khim

The port and starboard running lights: The lens (covers you call them) are tinted, the bulbs are white.

The 'submarine identification light', atop the snorkel, has an amber lens.

The anchor/stern light is white.

The mast head light is portable.



David

[Marylandradiosailor]

Thank you HWSNBN...


You mentioned that "The mast head light is portable." - I'm trying to better understand what you mean, does that mean that it is not attached to the hull and a crew positions it as needed or plugs it is or ?

[He Who Shall Not Be Named]

Thank you HWSNBN...


You mentioned that "The mast head light is portable." - I'm trying to better understand what you mean, does that mean that it is not attached to the hull and a crew positions it as needed or plugs it is or ?

Yeah, it's probably stowed in the trunk between control room and bridge when not needed and has to be mounted topside as required.

David

Op's. Bum dope on my part (assumptions made from TENCH and LAFAETTE class boat experience). Thanks for the correction, Bill.

[wlambing]

On 688s, the masthead light and sub ID beacon are both on a retractable mast that is hydraulically raised and lowered. We had a running gun-fight with an idiot officer who got blessed off on his OOD and SS quals on a 637, 'cos coming from a 688, he couldn't fathom that the masthead light on the 637 was hand-cranked up from the lookout pookah!!! Most childish acting, spoiled brat I've ever seen in Naval service. Eventually, he got forced to resign. Good riddance!

[Marylandradiosailor]

Thx for the information again folks.