Lindberg PT Boat

Dcp_3579.jpg (383663 bytes)
Still not done, but close.

This boat does draw a crowd, I was concerned when I first put it in the water, the extra weight from the motors and two 6 cell batteries put it pretty low in the water, the plastic is not like today's, this is heavy to begin with.
It cut through the water nice at low speed, when I hit high speed the boat lifted out of the water and ran just like the pictures of the real boat I had seen in old photos. The front half was riding on the top and about mid point was where the water was being pushed out.
The only trouble I am having is water getting in the hull, I am not sure if it is from the drive shafts or the vent on the top.

This is the old original, I also have the limited edition that came out later.

Original condition I received it in

At first I was a little disappointed in the general condition, then I realized that I was going to remove all the damaged items weather they were broke or not anyway.
I found a lot of junk on the inside, even part of what looked like a cheap RC car, the deck was glued on the hull and had separated in some spots, I had to remove it anyway to rebuild the drive system. The original motor (1) for these looks like a 180, something that would power your electric toothbrush, connected to brittle plastic gears that drove twin drive shafts.

I removed the top very carefully with an exacto knife (loss a little blood) and removed everything except the battery holder just in case I could use it, I didn't so it is gone too. 
The drive shafts were unsalvageable, they were seized in the brass stuffing boxes.
I used the original plastic motor plate as a template to make a new one from aluminum. I used two GP thrustmaster T600 motors, these are high torque and high speed motors.

Update: Suggestions on doing your own.
Cut away any excess plastic to lighten it, like under the cabin, leave the edge with the slots so you can still mount it.
Get the shaft couplers first, then size your shaft to them, then your stuffing box (brass tube) to the shaft, make sure you apply a lot of grease or Vaseline; water will travel up the shaft into the boat.
Glue, what to use? It has to be water and oil resistant and stick to this plastic, the motor plate came loose as you see it below, the second time I propped the boat at a downward angle and used half the tube along the bottom and side edges, about a half to three-quarter inch bead, after it dried, I flipped it and did the other side, it has held so far.

 

The drive shafts, 1/8" stainless steal are connected by Traxxas universal couplers, the two wood blocks are slotted and positioned to make the stuffing boxes, brass tubes, line up with the motors.
Shown is a micro switch power unit I made, one switch is a cut off switch, as the servo moves releasing that switch it connects the two batteries in parallel sending 7.2 or 8.4 volts to the motors that are wired in series, which divides the volts in half that each motor will receive, this is half speed. When the other switches are opened the batteries switch to "in series" sending 14.4 or 16.8 volts to the motors, this is full speed. See Controls & Wiring

Update:
I designed the speed control system originally for inline motors, this does not work well with independent motors, I am switching it to an ESC.

The picture above is the prime coat, a lot of work has been done on the deck, I filled the two openings on the back, originally they were for access to the steering linkage.
The deck and hull is secured together with screws, I filled the seam with wood glue as a filler and sanded the edges smooth, the deck can still be removed.

  Dcp_3586.jpg (324199 bytes)

I download a lot of pictures of the real PT boats and made the front 50 cal cage from heavy wire bent and soldered together. The armaments were ordered from HR Products, they are cast from a soft metal with a lot of flash that I removed with jewelers files, they also require assembly, I did not use glue, but carefully melted the parts together with solder. The back deck gun is a 20mm Oerlikon, the barrel was so thin it dropped from it's own weight, I made a new one from brass tapered down by putting it in a drill and using sand paper, I had to make the mounting bracket. The two Twin 50 Cal. Machine Guns require swivel bases that I mad from heavy wire. The original PT109 had a 37mm gun on the front deck, I will be making it from scratch.

Dcp_3588.jpg (345548 bytes)

The plastic mast that came with the boat was broke, I used it as a template to make one from brass, the support brace was designed from pictures of the real boat. The real boat had a large bulb at the top of the mast which was the radar unit. I decided to just add a working light.

 

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