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Merriman's Submarine Modelling

merriman

David Douglass Merriman lll
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You SOB!!!!

You know what buttons to push, don't you!!!!!!?????

Keep twisting that knife, Scott.

You sucked me into this f'n rabbit hole, and then you back-fill with quick curing cement!

I should have seen this coming.

David
 

merriman

David Douglass Merriman lll
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Well, Grey Havoc, I'll give Scott this: he did use the sharp knife!

David
Still To Hot To Touch!
 

merriman

David Douglass Merriman lll
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The larger volume ballast tanks of the Modular SubDriver (MSD) require a higher rate of air flow during the 'blow' cycle. My Boss sent me two large air-pumps to play with, the goal to optimize them to fit and mount within the tight confines of a 3" Lexan cylinder.



I had to hack and slash at the pump-motor housing to get it to fit within the cylinder. I found the best means of mounting the pump-motor unit to the cast resin ballast tank after union was with two lengths of K&S L-beam, everything secured with 2-56 machine screws.







Here I present the modified pump-motor and one stock, yet to be molested by the shop machine tools.







I have yet to affirm that this single-stage diaphragm pump will move water as well as air without leaking into the cylinder. That investigation to happen tomorrow -- but I'm confident, after examination of the seals (both diaphragm and check-valves) that no modifications will be necessary … we'll see.

The big issue is the need to come up with a snorkel valve and safety float-valve that can deal with the high flow rate and higher differential pressure -- that's gonna take some work!

David
 

merriman

David Douglass Merriman lll
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I'm brokering a ready-to-run r/c submarine for a friend. He's a bit disabled, but a good guy and a very competent model-builder, but is down to one hand now. So, another friend, Tom Chalfant, has provided this guy with a 1/72 SKIPJACK r/c submarine; I'm in the middle integrating a new r/c unit with the existing SubDriver system, checking out, and getting the boat operational before sending it to its new owner. This is some of that work:







And I continue to produce new masters to support our new Modular SubDriver (MSD) product. We're adding 3" unions and bulkheads that will increase the adaptability of the product:

















From these completed masters I'll make RTV silicon rubber tools from which I will produce cast resin production parts.
 

merriman

David Douglass Merriman lll
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Tool making took up most of today's shop time, but I did get in an hour to identify and correct one leaking pushrod seal in the SubDriver that goes with that RTR 1/72 SKIPJACK model I'm readying for a friend.

The leak identified after submerging the SD in the test tank and applying a little pressure -- if there are any leaks in the system they evidence as a stream of bubbles emanating from the problem area. Sure as shit, one of the seals was leaking. It was identified, the SD pulled out of the water, dried, and the bad tooth pulled and replaced!



As the pushrod seals are secured with RTV silicon gasket adhesive, it was an easy matter to push the bad pushrod seal out of the motor bulkhead and replace it with a new pushrod seal.



After the RTV had cured hard enough to reinstall the pushrod, I did so and made up the servo bell-crank to the pushrod and did the leak-test again to insure everything was water tight.



Time had come to mount all the MSD bulkheads, unions, and servo foundation masters on their respective mold-boards and prepare things for the first half of the RTV silicon rubber tools.

















 

merriman

David Douglass Merriman lll
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I receltly got an order for fittings to complement the GRP hulls of 1/96 KILO and BLUEBACK r/c submarine kits needed by my boss at Nautilus Drydocks. Typical resin casting job, but a nice departure from the boring MSD work I've been doing for so many weeks now.

These three beauty shots are of my personal KILO and BLUEBACK boats that I run for fun. Both are sterling performers on and under the water. And their relatively small size permits me to operate them in almost any body of fresh water. my go-to play toys!







And here are the gory pictures of the fittings being cast up and prepared for shipment.

















 

merriman

David Douglass Merriman lll
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The last few weeks have been invested in producing 'fittings' for r/c model kits. What I'm doing here is casting up resin and metal parts that -- when integrated with GRP hulls (produced by another manufacturer) -- will become commercially available kits; fittings for the Small World Models 1/96 KILO submarine kit.









I employed simple two-part rubber tools, and a more sophisticated three-piece tool to cast the stern-cone, sail, and appendages for the fittings kit.











What is it with Island-Girls and yard tools??…



The white-metal propellers were gravity cast, and the smaller detail metal parts were spun-cast in a modified blood-separation centrifuge.













The white-metal fittings that required machining -- taping, boring, and inclusion of set-screws -- were secured within specialized holding fixtures.





 

merriman

David Douglass Merriman lll
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A quick recap:

Bob Martin and I have collaborated in the development, production and sale of an improved SubDriver, the Modular SubDriver (MSD). A system that controls, propels, and manages the variable ballast water of an r/c model submarine.

The MSD's advantage over the other system is the interchangeability of the three spaces -- one at each end which are dry, and the center space comprising the ballast tank. Whereas the SubDriver employed only one length of Lexan cylinder the MSD uses three lengths of cylinder. And the MSD does not make use of any mechanical fasteners to hold the internal bulkhead in place -- those bulkheads replaced by unions that permit like or varied diameters of cylinder to be joined as a unit.



The three cylinder sections are easily removed this permits easy access for adjustment, replacement, or normal preservation. Each cylinder section is cut to the ideal length to fit the boat the system will be used in.





I've provided for the use of three different diameters of cylinder -- the diameter selected for the three sections can be constant or varied depending on the size of the model as well as its length-to-beam ratio. The diameters available are 2.5", 3", and 3.75".



I've been at this project for over a half-year now and am nearing the final refinements of the MSD. Additions to the system that further increase its utility, no matter the application. A gear-splitter to develop two counter-rotating shafts from a single motor is one example.



The last of the work is development of masters for unions and bulkheads that will adapt 3" Lexan cylinder sections to the system. Here's that work:











 

merriman

David Douglass Merriman lll
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MSD beta-testing is about done -- that first pre-production set of tools put to use making Modular SubDriver parts which were assembled into systems, sold, customer critiques noted, and changes made.

I've modified the masters and now pouring production tools and manufacturing production parts. We're underway. Finally!



















 

martinbayer

CLEARANCE: Top Secret
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Were you really just smooching that casting in the third picture down in your most recent post right there above while cradling it fondly, and if so, does your spouse know about that?! Because that really could give the term "casting couch" a whole new different meaning...;)
 
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merriman

David Douglass Merriman lll
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Were you really just smooching that casting in the third picture down in your most recent post right there above while cradling it fondly, and if so, does your spouse know about that?! Because that really could give the term "casting couch" a whole new different meaning...;)
I DENY EVERYTHING!!!!! (please don't tell Ellie).

What I'm doing… Mr. smart-ass... is pressure testing the tool to insure that I have a leak-proof seal between the tool halves before pouring the catalyzed polyurethane casting resin.

David
 

martinbayer

CLEARANCE: Top Secret
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Were you really just smooching that casting in the third picture down in your most recent post right there above while cradling it fondly, and if so, does your spouse know about that?! Because that really could give the term "casting couch" a whole new different meaning...;)
I DENY EVERYTHING!!!!! (please don't tell Ellie).

What I'm doing… Mr. smart-ass... is pressure testing the tool to insure that I have a leak-proof seal between the tool halves before pouring the catalyzed polyurethane casting resin.

David
Well, I have a strong suspicion that it was actually your wife who took the picture in the first place anyway, so whatever this was (and sure, let's go with your explanation) was apparently consensual, so who am I to judge :).
 
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merriman

David Douglass Merriman lll
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Now, after seven months of continuous development, and pre-production work, I now hit the ground running as I get into the production phase.
Working up two and single motor bulkheads for the 2.5" Lexan cylinders:









Specialized templates and tools to speed production work of the Motor Bulkheads (MB).



Use of a low-torque drill motor, with adjustable ratchet clutch, to drive home the motor foundation support struts. The tool itself was turned from a length of 1" machine brass round stock outfitted with a big brass gear to give me something to grab when torqueing things down by hand. The end of the tool is drilled and tapped to engage the end of a stud.





 
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