Dumas Shelley Foss 36" tug build

[Frank v B]

Bow thruster- back to the drawing board.  Arghh!

here is the set-up for the bow thruster. 
This board stands up in the bow.  The servo links to both mouse trap pinch-off loops to select left or right. A bit like the control line combat fuel cut-offs.

Tested the pump.  Two problems:
i) it seems to be weak on 4.8 volts unless on 6 volts. It clearly says "5 volts" on the label.  I can always hide behind the fact a man never reads instructions and use 6 volts.  If it burns out I will have to go back to the drawing board.
ii) It appears it is not self-priming- that makes it tough because the water has to be brought up 4" before it hits the pump*.  May have to talk to Temac's pump expert- Pool Paul.  Will try to source a windshield washer pump but it will need a separate 12 volt battery source.  Not a problem but the boat is powered by a 6 volt lead acid battery.

Back to the drawing board.

Frank


* am trying to keep all joints above the waterline so if it fails it will not sink the boat.

[Frank v B]

Final prep before painting:
- glued in the rudder post.  The tube sits about 3/16" proud of the hull surface (photo 50, right side of photo) so the rudder does not touch the hull.
- shorthened the prop shaft housing once the rudder was in place so I could accurately place the prop in front of the rudder.
- added the prop shaft strut at the bottom of the hull.  Hard balsa, shaped it and epoxied it in place (photo 50).  Wrapped two threads of Kevlar* over it and onto the hull to strengthen it (Photo 51).  Added waxed paper and squeezed everything smooth (photo 52).
- added masking tape on the deck to start getting it ready for spray paint.  The hull will be black, the deck is grey.

Frank

* Kevlar is the gold coloured thread.  I use it because I have it.  You can use unwaxed dental floss.  It is amazingly strong in this application.

[Frank v B]

Building is pretty well done.
- sanded the hull's fibreglass covering smooth.  Wow! Never for a minute thought it would be this easy or this smooth.
- installed the motor, prop shaft and prop in place so everything fits.  The prop does not hit the hull!
- installed the rudder servo and rudder.  It fits.
- added the battery tray and fit the speed control (an RC car one with reverse).

Added the masking tape on the deck- ready for spray painting the hull. 
Only problem- cannot spray inside the house.  I do it on the driveway but not while ice cubes litter it.

Frank

[Frank v B]

Last day of the Shelley Foss build until painting it
- installed the ESC on the side of the hull.  Two reasons: i) water always collects in the bilge (bottom), ii) this boat requires lead to bring it to the waterline.  It is best in the middle (balance) and as low down as possible to reduce rolling in waves.
- installed the on/off switches for the radio and bow thruster.  Purpose- so the boat can be assembled in the car and powered up when in the water.  This boat will probably weigh in the neighbourhood of 15 plus pounds.  My back!!
- wanted the access to the switches through the deck.  Cut a hole below the deck winch, installed the switches and built a raised coaming around the hole.  It is a lip to stop water running over the deck and into the hole.

Frank