1/48 3D Printed USS Jimmy Carter

[jphatton]

Here is the link to the thread on the Thresher PUFFS arrays for reference

https://forum.rc-sub.com/forum/general-topics/147016-thresher-permit-control-surface-bearing-blocks-hydrophone-end-plates

[jphatton]

David, Steve,

For reference attached are plan and side view projections of the Thresher PUFF's array with dimensions from the Thresher CAD model I made a while back. These were based on photo interpretation / measurement from the Thresher wreck photo's so there is some uncertainty in the actual dimensions, so don't take the 1/4" resolution on the measurements as an indication of accuracy... I need to check my notes again to see if I made some better refinement of the measurements - also I made a post on the forum a few months back with some more details and assessment, I just need to find it again for cross reference (Steve, if I recall correctly this is what you used as reference for your model?).

The Thresher wreck photo's show that the PUFF's arrays were installed on Thresher at the time of her loss. Also there is a drydock photo of USS Barb showing the PUFF's installed, but no other photographic evidence they were installed on other boats of the class.

[He Who Shall Not Be Named]

One more top section came off the printer. Just three more to go and the hull parts will be done. Lots of sanding, fitting, filling and sanding to do.



What are the raised areas on the lower hull? As modeled they have very rounded corners. What images I can find they appear to be less rounded.

Those six (three on each side) stand-off structures contain arrays of hydrophones that are electronically scanned. They are Wide Aperture Arrays (WAA). Passive sonar that, because of the geometry of their positions on the hull, can derive useful bearing AND range of local noise sources; lets you work up a useful solution without pinging yourself. This is the current offspring of the old PUFFS. Pretty slick. As the exterior structure of all modern American submarines are about 70% pressure hull you can't inlay the WAA hydrophones, that's why the arrays stand proud of the hull. Ugly, but serviceable.

Break out the Bondo and soften the edges between WAA structure and hull. A convex, not concave transition.

https://youtu.be/2O8gTIr4lys

David
Task Master

[SubDude]

One more top section came off the printer. Just three more to go and the hull parts will be done. Lots of sanding, fitting, filling and sanding to do.



What are the raised areas on the lower hull? As modeled they have very rounded corners. What images I can find they appear to be less rounded.

[He Who Shall Not Be Named]

You are a frig'n Machine!

[SubDude]

Ok. Tail feathers are done. I now have separate outer tip planes, gudgeons and pintles and inner planes. Next I will work on the control linkages.

[He Who Shall Not Be Named]

Port side is done.

Well done, Steve!

[SubDude]

Port side is done.

[SubDude]

I got the tube (sleeve) today and got it in place. Everything works smoothly as it should. Gudgeons are secured with screws and sanded to shape. Next up will be to secure the tip planes.

[SubICman]

Yeah, I see with PUFFS hydrophones. I am somewhat familiar with PUFFS, but the ones that look like large sharks tooth topside. Good find

[SubDude]

Steve, where did you find that the vertical stabilizers were on the Permits?

Right around page 25. THRESHER went down with them installed. Not saying the Permits had them. I believe they were quickly replaced by better technology. There is also some scuttle butt about whether it went down with a 5-blade Skipjack prop or quieter 7-blade prop. I tried to model mine as she might have looked at the time of her loss. I went with the 7-blade prop for several reasons. Document refers to them as 'puffs'. 0859672.pdf

[SubICman]

Hey, Steve. Would you send me drawings of the THRESHER's vertical stabilizers in relation to the horizontal stabilizers they were affixed to? Thanks. Want to have my 1/96 and 1/72 THRESHER's ready for Red Clay.

David

Steve, where did you find that the vertical stabilizers were on the Permits?

[SubDude]

Echoing Dave, Nice work! That is a good recovery and smart with the screws, allows for easy replacement if required. A lot of our methods don't allow for easy replacement or repair of broken parts

Thanks. Yeah as much as possible I try to build my subs with the ability to remove and repair or replace in the event I prang something.

[SubICman]

Echoing Dave, Nice work! That is a good recovery and smart with the screws, allows for easy replacement if required. A lot of our methods don't allow for easy replacement or repair of broken parts

[He Who Shall Not Be Named]

You are most welcome. Spent time today designing and printing the gudgeons. Got the starboard side roughed in. They will be secured with small screws thus allowing them to be removable. The tubing I need to install for the tip planes will be here tomorrow and once secured I can sand the gudgeon to its final shape and fill any gaps that may remain.

Nice work, Steve! And looking forward to the final result on those tail-feathers.

David