Albacore continued

[greenman407]

Here is a short video of her today. At about halfway thru the video you can get a glimpse of her below the water speeding along at about 3/4 throttle.http://www.youtube.com/watch?v=FI5dj...ature=youtu.be

[greenman407]

Today we got in a little run time with her. Then surfaced a re-occurring problem. The dive planes are jittering too much again. You could probably get away with it on a standard cruciform rudder sternplane arrangment, but not with an x tail. Its just too sensitive. If you operate at slow speed with her you have no problems. As you increase speeds she starts the "Up and Down" movements again. Whats interesting about this is, a couple of weeks ago she went full speed with no problems. Now we are back to jittering again. As you know I detected this early on and for that reason I tried multiple ADF2s as well as a Thor pitch control. But to no avail. So I put it up front with the Battery. I guess its picking up on vibrations again. I think Ill try a layer of thin bubble wrap between the battery and the shelf that the ADF2 is mounted on. I have to get this problem solved once and for all. There is no need to buy new more powerful motors If I cant use them.

[Slats]

Can do on the 3.5 SD's. But not likely on the 2.5 and 2 SD's as the larger diameter conduit tubes gets in the way of the gas and/or safety float-valve.

David

Understand David
but can you do it on the 3" as well?

J

[He Who Shall Not Be Named]

Can do on the 3.5 SD's. But not likely on the 2.5 and 2 SD's as the larger diameter conduit tubes gets in the way of the gas and/or safety float-valve.

David

[Slats]

If it's any help, you can cut that down to five wires, as the red and black wires are superfluous from the ESC (controller already grounded via battery and +5 not required with a separate BEC). Also bear in mind that most people run much larger diameter power cables than they need for the current required. That's not a problem when you have plenty of space, but if things are a squeeze, then it's an advantage to optimise.

The cables that are usually soldered into ESC's tend to be way thicker than required for scale models.

20AWG cable will safely carry 10A, which should be ample for the size of boats being built here.

If you really wanted to be frugal, you could use the tube itself as a ground conductor, that would cut the wiring down to just four wires!

Andy - my wired minimum could be in light of your superior electrical engineering a bad example. BUT we need a bigger diameter as its not as simple as what you suggest. I'm not sure if you actually have a Casewll Sub Driver but in my experience (I have had 5 of them at last count) you need to have give in the wiring flowing through the conduit and / or separate connectors for this umbilical for opening up and removing the motor tray and the battery compartment. I have reduced the size thickness of all my cables down to the size you suggest and am still running into catching problems with the minimum wires I'd like to run through the conduit and ONLY when I have to get into the SD. You cannot control the wires movement along the conduit from outside of the cylinder AND given the large length between the cylinder end and the conduit on the walls of the ballast tank, its not that easy to re-guide them through with your hands, a hemostat or long fingered pliers / tweezers, once the end caps are off. A bigger diameter is needed for basic practical reasons -ergonomics, and making its more simple to access the abundant forward real estate, and allow give in the somewhat unpredictable movement of the wires.

Moreover given you need easily removable connections for these umbilicals. (i use simply servo connectors male and female for the RX control for the ESC). I did know that you could just go with a one wire signal - but the very first time I unconnected this to a servo connector I snapped the wire. I then did it twice again! When I have ran the ESC in the forward compartment since, I run all three wires through the conduit of as its a stronger connection and the pathway it takes through the conduit is a heck of a lot stiffer and more predictable as all three, like any servo wire, come pre stuck together. The red wire from the ESC is made redundant only on the RX plug at the RX in the motor tray compartment. For the separate BEC / VR, when I has this in the battery compartment ,I ran servo wires (using just 2 wires) and again used servo connectors at the motor end.

In my last post I made a mistake and left out two wires - these run 7.2 volts to the LPB pump. These are about half the thickness of the 20AWG cable that I use between the ESC and the Motor. A way around this is put the BEC /VR in the motor tray area - eliminating that umblical, and getting the BEC to pick up the 7.2v supply going to the LPB pump, but I wanted to keep the BEC well away from the RX

Sorry but not prepared to try the conduit as a ground connection, have had a decade of wet connections experience like this (albeit on a small scale) and had a decade of headache glitches. I will not run a wet electrical connection on any RC submarine ever again, and a key reason why I pushed David so hard to put the conduit through the guts of the Subdriver on the 3.5" -to keep it all dry. The two lakes I run in have proved time and time again that they punish submarines with anything exposed to their specific mineral content in the water (and its by no means brackish these are freshwater dams). Ask David about the hell I went through with the wet connections of the torpedo pneumatic controller (which were thoroughly greased up and worked 100% of the time in the pure water of my test tank) and failed 95% of the time where I sail.Those connections were all GRN connections!! This is a key resaon why the Torpedo system I run in my boats is of the mechanical launcher type - works every time:)

So thanks but no thanks Andy, David please proceed as Mark and I suggest.

[Subculture]

-3 wires from ESC to RX
-2 wires from ESC to motor
-2 wires power supply to feed 5v to RX and the LPB unit
(7 wires in total).

If it's any help, you can cut that down to five wires, as the red and black wires are superfluous from the ESC (controller already grounded via battery and +5 not required with a separate BEC). Also bear in mind that most people run much larger diameter power cables than they need for the current required. That's not a problem when you have plenty of space, but if things are a squeeze, then it's an advantage to optimise.

The cables that are usually soldered into ESC's tend to be way thicker than required for scale models.

20AWG cable will safely carry 10A, which should be ample for the size of boats being built here.

If you really wanted to be frugal, you could use the tube itself as a ground conductor, that would cut the wiring down to just four wires!

[Slats]

I know which horse to put money on, pal. You came through in the streach.

David

[ATTACH=CONFIG]17546[/ATTACH][ATTACH=CONFIG]17547[/ATTACH][ATTACH=CONFIG]17548[/ATTACH][ATTACH=CONFIG]17549[/ATTACH][ATTACH=CONFIG]17550[/ATTACH]

Drooling. -
Was wondering about the phase 2 removal of the Dorsal rudder.
The Albacore page, http://www.ussalbacore.org/html/albacore_story.html
says the Dorsal Rudder was removed during phase 2 - which had the cruciform rudder and stern plan arrangement BUT my question is was when did this occur? I.e. Was the Dorsal removed right from the get go or was it something they lopped off after the planes and rudders of the cruciform initially were tested?
J

[Slats]

Could you guys live with about 1/2" ID? Bigger and I start to crowd things on the after ballast bulkhead.

David

What is the current size David?
i.e. how much bigger is 1/2" to the current size we have?

Currently I am just running 2 wires through the conduit (have given up on more than this due to snagging wires). These wires are that from the battery.

At a minimum, I'd like to comfortably put in the battery compartment forward:
The battery
The ESC
The separate BEC.
To do so means I'd be running through the conduit.
-3 wires from ESC to RX
-2 wires from ESC to motor
-2 wires power supply to feed 5v to RX and the LPB unit
(7 wires in total).

Could you go up to 5/8" David? K & S do have brass tubing that size.


Thanks

J

[He Who Shall Not Be Named]

David
just found this K & S product sheet: http://www.ksmetals.com/resources/cuttolength.pdf
Would seem they do 3/4" OD in brass tubing, but with three lots of wall thickness ranging from 0.011", 0.020", 0.029"
You could for the bigger diameter SD's (3" and 3.5"), go to their 7/8"OD without compromising too much the ballast tank capacity. - Guess it depends too on what o'ring sizes you can find to seat inside the bulkheads.


Best
J

Could you guys live with about 1/2" ID? Bigger and I start to crowd things on the after ballast bulkhead.

David

[Slats]

David
just found this K & S product sheet: http://www.ksmetals.com/resources/cuttolength.pdf
Would seem they do 3/4" OD in brass tubing, but with three lots of wall thickness ranging from 0.011", 0.020", 0.029"
You could for the bigger diameter SD's (3" and 3.5"), go to their 7/8"OD without compromising too much the ballast tank capacity. - Guess it depends too on what o'ring sizes you can find to seat inside the bulkheads.

Best
J

[He Who Shall Not Be Named]

I know which horse to put money on, pal. You came through in the streach.

David

[greenman407]

Digging thru my Archives , I found these. I believe, if I remember correctly, that these pictures are of Skip Assays duo prop Albacore showing two motors with belt drive in the wet. Looks like he has put clear sleeves around the motors. He never mentioned whether it was successful or not. I also want to mention that the credit for the mechanics of my installation go to HWSNBN(He Who Shall Not Be Blamed). When I inquired as to the feasibility of such an installation several years ago, Dave responded with parts and a description of how to do it. With very few changes, I have reproduced his design. I bet he never thought that I would complete it since I usually work at a snails pace and am easily distracted. Thanks Dave for the good stuff!

[He Who Shall Not Be Named]

OK, this from two guys who's opinions carry weight with me. I'll look into it, guys.

David

[Slats]

I would venture that the present conduit appears to be 1/2". Perhaps a 3/4" would provide more space without impenging too much on the ballast tank

I concur 3/4" would be very helpful. Do K&S Brass people make a tube that diameter? If so...David please make it so. I for one would be happy to buy upgraded ballast tank bulkheads for my existing 3.5" Subdriver with this larger conduit. If you could supply these too as part of the 3" SD from the get go that would be great.

J

[greenman407]

I would venture that the present conduit appears to be 1/2". Perhaps a 3/4" would provide more space without impenging too much on the ballast tank