Project 641 Foxtrot Update

[herrmill]

Re: Project 641 Foxtrot Update

Here's a preview of the photo etch for decks & grating.

[herrmill]

Re: Project 641 Foxtrot Update

Here are some photos that David sent out today as he preps the hull for running gear & accessories.

As requested by those who first proposed a kit, the hull will be split horizontally at the waterline to allow full access. As you can see, there will be plenty of room for running gear & torpedo launchers should you want to go all out with this beast.

David's prototype Sub-Driverâ„¢ for the Fox with its 3 direct drive motors which will include an ESC on the central shaft that will kick in at 75% power for full ahead & astern applications. Anything under that, the port & starboard shafts would be turning just like the real thing which will also go a long way towards conserving your battery power.

[Guest]

Re: Project 641 Foxtrot Update

Here's my dumb question of the day, although that saves juice, will it make the turning performance worse. As a land lubber I was under the impression that with a prop in front of a rudder it made for a tighter turning circle, as the wash from the prop will assist.

With this being a long skinny hull, i can imagine that the turning circle is going to suck, and have been wondering about a mixer for low speed turns???

[herrmill]

Re: Project 641 Foxtrot Update

Here's David's cabel report along with photos of the new SubDriver for the Foxtrot.



Last week I spent my time developing a purpose built SubDriver (SD, some of you call them WTC's) for the Rick Palumbo 1/72 FOXTROT kit. This thing will be marketed through Caswell Inc., Rick's kit represents what I consider one of the most beautiful boats of the cold-war. The model is just the right size to crame in a full bridge and periscope-antenna array and deck items A detail freaks dream boat!. But, this beast will not be so big as to be a storage, display, and transportation burden.

Two things drove the design of this SD]http://i131.photobucket.com/albums/p292/herrmill/002-2.jpg[/img]

Atop is a completely outfitted, operational 2.5 FOXTROT SD. Below is a broken down FOXTROT SD, showing off the bulkheads, mounting hardware, seals, and fittings that goes into the manufacture of this SubDriver.

As is my practice, the SD is divided internally into three spaces]http://i131.photobucket.com/albums/p292/herrmill/003-2.jpg[/img]

Neither Rick nor I have put an evaluation FOXTROT hull in the water for trials, so right now it's a guess as to how effective differential operation of the port and starboard screws will be in turning the boat. My fear is that without differential use of the propellers, the FOXTROT model will turn as poorly as the German Type-21 the FOXTROT was based on! Further, if the two outboard shafts are toed in, like the Type-21, then the yawing force will be opposite to that which is normal, or there won't be any appreciable yawing moment at all.

So, to find out how effective differential throttle use will be on the boats turning rate, I produced an evailuation motor bulkhead that has all three motors in parallel (starboard motor turning clockwise, center motor turning clockwise, and the port motor turning counterclockwise -- these motors will be driven through one common ESC. This is the baseline arrangement. I get this one.

A second evaluation bulkhead has the starboard and center motors wired together in parallel, and the port motor wired alone. Two ESC's will permit differential use of the starboard (along with the center shaft) and port shafts -- we'll see if differential use of the propellers will effect useful yawing forces. Rick gets that one.

The running gear is simple]http://i131.photobucket.com/albums/p292/herrmill/004-2.jpg[/img]

The three 180 sized motors took up so much area on the motor bulkhead that I was forced to employ threaded studs as stand-offs to support the aluminum device securing platforms and bulkheads. Here you see an early version of the bulkheads and platforms within a cylinder, and a motor bulkhead with the three studs installed just forward of that cylinder.

Note that I glue three micro-sized servos side-by-side. These will later be secured with a single brass strap to the device platform. Took about two days of trial and error to get an arrangement of bulkheads, and platform to fit all the devices in a tight and coherent arrangement.



And here is a motor bulkhead with all devices installed, and operational. Thank goodness for the Sombra Labs 8-channel receiver! It's not only small, but so selective and noise immune that I can put it in what has to be the most terrible of RF environments]http://i131.photobucket.com/albums/p292/herrmill/007.jpg[/img]

Next to the ADF is the bullet-proof little MTronic's ESC. Though small it has the capacity to keep current going to the nearly stalled motors without breaking into a sweat.

At the after end of the after bulkhead you see the green circuit-board of Kevin McLeod's little LPB controller.

The white wire making up to the forward face of the motor bulkhead is the receiver antenna. The lug it mounts too extends through the bulkhead to the wet face of the motor bulkhead where the external antenna makes up to it.

The battery cable connects to the battery and switch after it passes through the conduit tube within the ballast tank. The cable makes up, in parallel, to the ESC, Lipo-Guard, and LPB motor controller. The ESC has a BEC that feeds the receiver bus, that powers up all the devices connected to the receiver.



Looking down on the top of the motor bulkhead The red thing is Kevin's Lipo-guard battery protection circuit, under it is the Sombra Labs 8-channel, synthetic crystal receiver -- the brains of the SD! Just behind the motors, and strapped to the aluminum platform, are the three mini servos that operate the stern planes, bow planes, and rudder.

Pretty tight packaging, huh?!



The device mounting is pretty sophisticated! three motor bulkheads here and the aluminum bulkheads, platform, and brass strap that secures the devices in place tightly, but with good access for adjustment, repair, and or replacement. There is a method to the madness!



Use of production templates, holding fixtures, and jigs insures speed of manufacture and uniformity of part fit.



A snorkel induction tube atop the FOXTROT SD will run up into the after fairing atop the FOXTROTS sail. Induction air will be pulled from atop the sail as it broaching the surface. That air, pushed into the ballast tank by the LPB, empties it, pushing the boat to surfaced trim. The on-board bottle, with its charge of liquefied gas, is only used in emergency -- when, for whatever reason, the boat can not broach the sail. The emergency blow ballast sub-system is either actuated remotely, through the transmitter, or locally, through Kevin's missing pulse detector -- an element of the ADF device.



As tightly as I packaged things in the FOXTROT SD's after dry space, I still left a two inch space between the devices and the after ballast bulkhead. This space for 'future growth'. Who knows?!



My FOXTROT SD. Rick's goes out Tuesday!

[herrmill]

Project 641 Foxtrot Update - The Home Stretch

Well guys, we're in the home stretch now & Project 641 "Foxtrot" is nearing completion.

Rick's work on the mold is complete making this, without a doubt, one of the most detailed GRP hulls on the market & kit production has commenced this week, while David's back to finishing his prototype model after getting it wet for the first time.

More details & photos can be seen at:

http://forum.sub-driver.com/showthread. ... production

http://forum.sub-driver.com/showthread. ... d-Merriman

[greenman407]

Re: Project 641 Foxtrot Update

Herrmill, looking forward to seeing yours in the water and your trimming process.

[tom dougherty]

Re: Project 641 Foxtrot Update-Whatever Happened to this project

OK, since I have an interest in the Foxtrot/Golf class of Russian subs, I was following this project along. Now things have gone dead silent for more than a year. Is this still on track for production, delayed, defunct? Anyone know?

[thor]

Re: Project 641 Foxtrot Update

I'm not sure, but I think the project was terminated by the producer of the kit.

[tom dougherty]

Re: Project 641 Foxtrot Update

Thanks, Matt.
Wow, after all of that work, another one bites the dust. I think it would have been a decent seller, since it is a bit off the beaten path.

[greenman407]

Re: Project 641 Foxtrot Update

Who was the producer of the kit? The model in this thread, was it ever finished and became operational?

[salmon]

Re: Project 641 Foxtrot Update

Rick Palumbo did the model and was working in a unknown capacity relationship with Caswell and D&E. There were some issues in Rick's life and some people were not getting a sub they had paid for after several years. The relationship was severed. And Rick has started this site with the sub listed:

http://www.scalemodelcastings.com/172-scale-Russian-Foxtrot-submarine-kit_p_82.html

The WTC and fittings kit, I believe, was a D&E (David Merriman) creation.

[greenman407]

Re: Project 641 Foxtrot Update

Thanks a million

[thor]

Re: Project 641 Foxtrot Update

Thats good info. Thanks, Tom. I stand corrected.

Matt

[salmon]

Re: Project 641 Foxtrot Update

I just re-read my posting and the people not getting their subs were Rick's sales and not Caswell. Rick's issues, which I am not sure those have been cleared up, put a spot on a very talented individual. Caswell, to my knowledge, has fullfilled all orders.
Peace,
Tom

[giovanni]

Re: Project 641 Foxtrot Update

Too bad!
I wanted to order the Holland submarine.