today's work

I started a 3" motor-bulkhead master. This diameter is just big enough to get intermediate sized brushless motors in there, side-by-side.











A forward 3" bulkhead, outfitted with two servos is the objective of this work. I'm mocking up such a unit, once validated for correct operation it will be taken apart and the parts used as masters to make tools for resin casting of the production parts.

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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

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.

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.

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!



https://youtu.be/W9Pg0zGb5Wo





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