A new single screw 3.5” SD?

[Slats]

Hi guys (and particularly David).

Mike suggested I post this.

One thing I happen to love about the D&E 3.5” SD is the 3:1 offset gear box. The reason I like this is that in the fairly larger diameter submarines (like a USN nuke) in 1/72 scale, you can fit the vast majority of the SD below the WL. In doing so I find the standard ballast tank a tad big, but in its current form, this is no problem as you can lop off a little ballast tank or using the end cap at the forward end – even add if you need to, a little foam.

I find that the new emergence of better battery technology, higher capacity LiPos and NimHs and lower weight, that there is a need for a forward battery dry compartment. Yes you can still run your SLAs wet instead of these newer tech batteries, and you can do what I have done on HMS Trenchant and employ your own dry space (and Mike indeed sells this), I am wanting to know however, if we could get a 3.5” SD single screw that comes with this feature installed i.e. Rear compartment / ballast tank / forward battery compartment – and with a conduit going through the ballast tank linking the compartments?

I would suggest a basic size of the ballast tank of around 5.5 – 6 inches, forward compartment of around the size to accommodate a 7.2 v NimH stick battery – like used in RC cars, and the rear compartment around the standard current size of this compartment on the 3.5” SD.

David and Mike, would this be possible?

Also Mike, on your web page could you please put dimensions up of what the current lengths of the SDs various compartments are?

Best

John

HMS Trenchant -3.5" single screw SD with 3" forward battery compartment. What I am suggesting is a 3.5" SD that has the battery compartment attached to the SD and connects to the rear WT compartment via ballast tank conduit.

[He Who Shall Not Be Named]

Sure, I can do this. And I would make the forward ballast tank bulkhead in a variety of types, each type accommodating a different diameter forward (battery) compartment.

It would entail a re-design of the after ballast bulkhead (incorporation of the conduit tube foundation).

Doable? Sure. Enough buyers out there to justify the work? You tell me.

Good stuff, and food for thought, John.

Anyone else want to pile on with suggested 'improvements' to our product line here in, CaswellWorld?

David,

[Slats]

Well I certainly will buy one.
I need to know more about the real estate and functioning requirements of the torpedo system first but count me in for a new 3.5" SD later in the year.
(The 10 degree angle and firing equipment on the Permit tubes might come across the SD space -so a smaller diameter battery compartment might be required).

I think others who want to run the new tech batteries etc will want one want too. As stated on an early post larger submarines can benefit from Lipo technology too. i'd like to still use NiMH but if the space (dry section is there) I can always switch to Lipos and add ballast later.

best
John

[toppack]

Mike, on your web page could you please put dimensions up of what the current lengths of the SDs various compartments are?

I really Like that Idea! :)
Come on, Mike, it will only take a few minutes and a yard-stick! ;)
In fact, David Should have all that Info on file, in his Super-computer, already? :D

[Kazzer]

I really Like that Idea! :)
Come on, Mike, it will only take a few minutes and a yard-stick! ;)
In fact, David Should have all that Info on file, in his Super-computer, already? :D

Hey! Ho! Already done it last week! We're waiting for our very slow, pitiful web page master (are you watching this Lance?) to get the thing posted.

In the meantime, here is a pdf file of the page.
www.moonrakers.com/Sub-driverwebpage.pdf

[toppack]

Wow! Great Info!
I'm going to do a Print-out of that one and hang it on my wall. ;)
Move over Pin-up Calendar! :D LOL

It's Okay Lance, we forgive you. :D

[Slats]

Mike good info in that file,
AND along the lines of my post here its notable that for the 3.5" SD kits you mention that you might need a forward battery compartment, but believe me its a far nicer unit with this connected to the SD with a conduit through the BT.

The ballast tanks are really massive 9" in length could drop that into a 1/72 scale LA and still have to cut it down. The rear compartments are a nice size.

Now getting back to the post - how many out there would like a 3.5" SD with a forward section - or is it just little ol me?!

I am also thinking that the section might also accommodate (if diameter was large enough) forward push rod / servo for bow planes / or that torpedo firing system.

J

[Nuke Power]

I have an idea or 2 David.
How about modifying the aft equipment tray to include a snort specific mounting point. Just like a sub driver has it cradles why cant the snort. Mine is in there all crooked and it tends to bend the airlines.

A thicker lip on the motor endcap would be nice for strength. That way dumb mechanics can use their screw drivers to pop the end off without damaging the cap.

Also have you ever thought about redesigning the gear train?

[He Who Shall Not Be Named]

I have an idea or 2 David.
How about modifying the aft equipment tray to include a snort specific mounting point. Just like a sub driver has it cradles why cant the snort. Mine is in there all crooked and it tends to bend the airlines.

A thicker lip on the motor endcap would be nice for strength. That way dumb mechanics can use their screw drivers to pop the end off without damaging the cap.

Also have you ever thought about redesigning the gear train?

Good points ... mind your own business, bilge-rat.

David,

[Nuke Power]

"Anyone else want to pile on with suggested 'improvements' to our product line here in, CaswellWorld?"

Hmmm silly torpedoman. ASks for ideas then gets angry. Its not like I said "fire david" or "start over from scratch..without david"
Sheesh. If you want to hear what I have to say about the drive train drop me a pm. Some people I swear.

[toppack]

Man, Am I the Only one on this forum that's Not in a Bad Mood? :D LOL :D

It must be time for everyone to change their medication. :D

[Slats]

"Anyone else want to pile on with suggested 'improvements' to our product line here in, CaswellWorld?"

Hmmm silly torpedoman. ASks for ideas then gets angry. Its not like I said "fire david" or "start over from scratch..without david"
Sheesh. If you want to hear what I have to say about the drive train drop me a pm. Some people I swear.

Have PM'd you re the drive train - got me curious.

I love the gear box and its flexibility to be removed - reorientated etc.

But seriously will this new SD happen? Is there a market for it. Just seems like a normal evolution re battery technology to have the dry space up front for the batteries.

[Nuke Power]

I am for the addition of a battery compartment to the 3.5 drivers. I, like you slats, have just been using an aditional wtc for the battery. Why not offer the variant. If you make it a double ended endcap it would be a pretty simple improvement for you to make david. Ofcourse you would lose the solid tube design, which in my opinion is a major bonus with your cylinder..Oh options options.
As for the gear train. I would like to see the gears move into the dry space. Especially on the mod 2. I am a rickover fan, minimize the hull penetrations.

[Slats]

I am for the addition of a battery compartment to the 3.5 drivers. I, like you slats, have just been using an aditional wtc for the battery. Why not offer the variant. If you make it a double ended endcap it would be a pretty simple improvement for you to make david. Ofcourse you would lose the solid tube design, which in my opinion is a major bonus with your cylinder..Oh options options.
As for the gear train. I would like to see the gears move into the dry space. Especially on the mod 2. I am a rickover fan, minimize the hull penetrations.

Yes that would be the easiest way - double end cap- and you could even downsize the forward battery compartment diameter like David has suggested and I have done in Trenchant. What I am for though is the conduit through the ballast tank. You get a neater result and less to worry about if all your electrics are inside. Also - I do like the idea of being able to have the ESC up with the battery and or other gear - servo for planes / torpedo activation etc.

The gearbox inside is not a bad idea although I still like to see it offset, so the final drive is above the centre line of the WTC, this means you can mount the SD lower and get away with a smaller BT. In large 72 scale subs USN nukes etc you would still have clerance under the SD to the bottom of hull so you would not be mounting the SD on the base of the hull, which I have demonstrated last year in my Oberon to be the worst thing you could do - parking air (boyancy) of an empty tank at the lowest possible point! (Massive instability problems resulted).

A solution to the gear box situation is that David supplies the motor end cap as is, OR blank for the end user to fit their own gear box / motor internally and use a conventional shaft seal where ever you want it.

[Slats]

And as some have mentioned in the turning circles post those with big SLAs forward not suprising have discovered great mass momentum to overcome and turning problems.

A new 3.5" SD can assist with this.