1/72 Seawolf -2 separate sets of stern plan axles?

[Slats]

Guys,
with Joel's permission I have posted herein for discussion 3 of his Facebook photos pertaining to the axle layout of the Stern planes.







What you can clearly see is that there are 2 stern planes on each side of the boat (4 planes) controlled by two sets of axles.
Whilst Joel's engineering is stunning, I am wondering if this arrangement is overkill.
First following a KISS process - would it be better to have the outer stern plane simply connected to the inner one and therefore only requring one push rod link?

Second - given the sensitivity of stern planes to effect pitch, could the inner planes on their own be sufficient - thus leaving the outerones fixed and one push rod link only?

Third, Joel shows here the setup which needs to be installed prior to the upper stern hull being connected to the hull.
For the sake of access / repair / realignment of the planes - which IME will need to occur from time to time, any ideas on making access hatches etc?

Thanks



John

[ADDINGTON]

John,
I have trouble viewing the facebook site so many thanks for posting these shots.
Here is my take based on a build of Seawolf in 1/96:
All four of my stern planes were ganged to single pushrod. After trying multiple rods and other variations it was indeed the best way to go. During linkage experimentation I drove the boat with only the inboards operational, then tests with outboards only. The outboards actually had a perceived advantage in pitch control.
1/96 makes for a very cramped space and adjustments/refits are maddening.
Maddening.
Bottom line,
Joel's pictured hardware is EXACTLY what this model needs.
While I am a devotee of KISS, in this instance I must wholeheartedly endorse engineering and OverBuilding the stern plane linkages.
By all means-do it.
This design to me has the promise of 'set-it-and-forget-it.' Maybe a little lube oil now and then.
Certainly mechanicals all wear and fail, you can add access hatches or make part of the sterncone removable if you feel the need.
Joel has, from my view, elegantly addressed the single most confounding element of building and operating a Seawolf, and this kit design continues to take the whole art to a new level.
-Kerry

[Albion]

is that single pushrod to control both, or two rods, one for diving and one for pitch?.

Very cool whatever it is. The 1/72 boats just have so much more space

[Slats]

John,
I have trouble viewing the facebook site so many thanks for posting these shots.
Here is my take based on a build of Seawolf in 1/96:
All four of my stern planes were ganged to single pushrod. After trying multiple rods and other variations it was indeed the best way to go. During linkage experimentation I drove the boat with only the inboards operational, then tests with outboards only. The outboards actually had a perceived advantage in pitch control.
1/96 makes for a very cramped space and adjustments/refits are maddening.
Maddening.
Bottom line,
Joel's pictured hardware is EXACTLY what this model needs.
While I am a devotee of KISS, in this instance I must wholeheartedly endorse engineering and OverBuilding the stern plane linkages.
By all means-do it.
This design to me has the promise of 'set-it-and-forget-it.' Maybe a little lube oil now and then.
Certainly mechanicals all wear and fail, you can add access hatches or make part of the sterncone removable if you feel the need.
Joel has, from my view, elegantly addressed the single most confounding element of building and operating a Seawolf, and this kit design continues to take the whole art to a new level.
-Kerry

Thanks Kerry.

I can see the utility of the larger surface area outer and inner planes as opposed to inner only.

If the planes all move in the same direction, my concern is I'd rather have 2 securing a grubs screws to maintain on 2 axles rather than 4.

My boat hull No. 002 will be jetting its way here soon enough so no doubt nothing like having it in your hands to review.

Best
J

[Slats]

is that single pushrod to control both, or two rods, one for diving and one for pitch?.

Very cool whatever it is. The 1/72 boats just have so much more space

Its a single push rod back to the WTC.
A very short double Z bended push rod connects the two axles together, so both axles move together and at the same rate.

Its just 1/72 here at play its the fact its a Seawolf, the biggest / fattest SSN on the planet.

Best

John

[spankey]

As far as I know, those outer sections of the stern planes act as roll dampers when the boat is operating at high speeds. Torque roll is already lessened by the pump jet, but the snap roll which is induced during turns at high speeds needs to be countered. These outer planes act as roll stabilizers (During high speed operations and on or near the surface)... At least thats how it was esssplained to me when I was standing under this thing in the drydock...

One thought is to purchase one of Caswell's angle keepers (like the ones we usually use on our stern planes), and instead of mounting this device longitudinally in the boat, you mount it in the athwartships direction. Using a bellcrank, you use a single servo which is driven via the angle keeper, to drive both of those planes, (like Ailerons on an airplane) and will operate your outer planes in the fashion that they were designed for.

This is what I plan to do when I get one of these boats.

[Slats]

The snap role might be a problem in the 1/1 scale world but we are not scaling water.

In my opinion of running subs these last two decades, snap roles tend to only occur at high speed with hard rudder, and in cases where I have experienced that a yank and bank of the stern planes is sufficient for fun, else reducing the rudder input. So in short its not a problem as its completely controllable.

I had thought however that the thing that will plague (possibly) this boat would be its turning circle. To that end I am toying with the idea of linking the outer planes to rudder controls, so you have a rudder over and aileron type input to thus banking the boat deliberately over. Think X fin rudder control but in cruciform.

[spankey]

It could work good. I like that also, and it definitely would help you turn the boat....roll the boat, then pull it through the turn. Yup, also a good option.

[Slats]

I'd be interested to hear what God has to say about it.

J

[ADDINGTON]

Spankey,
Thanks much sir for the insight regarding the outboard planes function.
If the outboards can aid the turning ability of a model, may I offer that it is definitely worth a try.
I have no knowledge of performance in the Trumpeter 1/144 scale, but anyone who has driven a 1/96 Seawolf will tell you the turning circle is horribly huge. I believe Mr. Eno has similar experience with his 1/48 SSN-23.
At the SubRegatta, I saw one 1/96 builder improve it greatly by tacking a clear acrylic extension onto the lower rudder, but let's assume that is an intolerable option for this 1/72 Ultimate Wolf.
John,
I read you loud and clear about grub screws on the stern plane axles/shafts. For my 1/96, I elimated the need for such by using a section of square tubing in my bellcranks and square rod for the plane shafts. This is now my preferred style for all dive plane/rotation applications. Shouldn't be too much of a mod if you wish.
And by the way,congratulations on landing command of hull # 002.
-Kerry

[Slats]

Thanks Kerry,
I purchased my Seawolf when it was on paper. Joel is an exceptional craftsman and I had complete confidence in him, so much so, and here is an exclusive for the SD forum, that Jim Russell and I have commissioned the first two 1/72 Astute class kits that Joel will be offering up as the next evolution to his kit line up. Jim and I have bought and paid for in full up front and "off the plan". Unlike some kit makers who announce products that go no where, Joel delivers. It did not take much arm twisting, I procured and sent Joel plans and he jumped at the chance. Both my Seawolf and Astute will utilise the Merriman Subdriver and torpedo system.

Turning is something that I have been able to improve via better all up weight reductions, and proper positioning of the WTC around the COG / COR. That said I'll experiment with the outer fin aileron type setup. The brass square pieces will be something to try.

Thanks
J

[Slats]

Am thinking that a problem that might arise with an aileron setup on the outer planes is that it could do weird things to the pitch of the boat and might be in conflict with the APC.

J

[Albion]

1/72 Astute class kits

:wink::biggrin: wah, there goes more pocket money, wont have any left for sweets now

[Slats]

:wink::biggrin: wah, there goes more pocket money, wont have any left for sweets now

Yeah its all sweet alright

[ADDINGTON]

John,
Are you using David's 3.0 or 3.5 SubDriver?
Either way, in 1/72 you'll have acres of space opportunities, annualar and elsewhere,for weight and foam distribution.
No doubt you will be able to improve/maximize the balance center relationships for better turning.
( My 1/96 used a 3.5 SD )
I guess the goal would be to achieve scale turning circle approximating( or better than ) the real boat?
-Kerry