RC Submarine build log

This project started when Pete Schumann (Mtflyr) sold me 1/72 Revell U boat type VIIC plastic model kit and David Welch(aka Big Dave)’s Experimenter’s kit for XXX dollars.

Experimenter’s kit is equivalent of ‘short kit’ in model airplane world. It is a noble way to say “you will do a lot of work and you will add a lot of your stuff “.

  • The kit content:
  1. 4 large end caps and 1 smaller end caps without any opening.
  2. 4 cylinder’s about 8 inches long and one smaller one 1 1/2 inch long.
  3. 2 vinyl bladder , 1 pump

1 CD with instructions – 2 pages long word document with some photos (Pete says it was extra $10). In my opinion, it had less information than typical RCgroups.com thread. Not much was helpful since I thought of adding ADC (automatic depth controller) and different propeller drive system.

  • Shopping list (beginning):

Remind you, what I had was 1st generation kit (v1). There are several updates and there are significant improvement over the kit I had.

The kit is not designed for Auto depth controller(ADC) but I wanted to see how it works and wanted to have it in my boat. It takes quite a bit of real estate inside the cylinder and restricting install requirements made things even harder.

  1. 3mm shaft seals (control rod and motor output), grease, propellers from Alexander Engel in Germany.
  2. Drive shaft – Tamiya 3mm shaft set.
  3. Electronics: Automatic depth controller (ADC) Automatic Level Controller (ALC) and electronic switch (SFS) with amplifier mosfet which I really didn’t need. It was package deal. I bought these from Subtech in Singapore.
  4. Dumas Coupling Rod and cups 1/8″ diameter
  5. Gearbox: Complete Gearbox: Mini Cub
  6. Three servos: I recommend small high torque (21 oz-in, 1.5 kg-cm) servo Futaba S3114
  7. 7ch Receiver
  8. Deck with openings (later, I cut my own deck with laser cutter)
  • My board

I designed a board with two ESC on board using PIC 16F628. It was designed for RC tank with two H-bridge. For RC submarine it could be easily converted. One bridge powers propeller forward and reverse and the other bridge controls a pump (forward) and a valve(reverse).

Later I added Static depth control system. I didn’t need it to be variable but I wanted my boat can maintain its depth at 6″ below surface when it is not moving. 6 inch is periscope depth of 1/72 scale Uboat VIIc.

Commercially available Auto depth controller (ADC) is capable of maintaining the depth at 6″ below surface by manipulating bow plane, but the boat has to move to make things work.

To be continued…

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