Chop’s PT Boat

[Chop]

O.K., this is my first attempt at building a boat from a kit, and my first scale boat as well. I just wanted something that was a little different than your usual “race boat.”

The model is a Lindberg Limited Edition PT-109. I don’t know if I will keep the 109 designation – it’s probably been way overdone. Maybe I’ll do PT-73 from McHale’s Navy??? Or PT-694, the real designation of the boat used in the action shots for McHale’s Navy.

The hull and parts are plastic.

Powder for the craft will be provided by 2 M.A.C.K. Products 3150 brushed motors (12v, 4.5 amps – max.) and the ESC is a Proboat Riptide (Continuous Maximum Current: 40 amps, 4-10 cells, w/ BEC & reverse)

The Photos are the parts out of the box and the beginning stages of construction.

[Jimmy Sterling]

Can I ask where you got the kit from

Thanks
Jimmy :tiphat:

[Chop]

From Mack Products (http://www.mackproductsrc.com/index.htm).

Seems like a pretty good store. You can't order on-line though, but if you call you can talk to them and ask questions. You can then order over the phone.

[Chop]

The deck of these boats were made of wood. From what I understand much of the boat was in order to save steel. The picture on the cover clearly shows this. I was not sure how I could transform the green plastic into wood without too much work. I finally settled on a wood grained shelf liner picked up at the local building supply store. I think with a good layer of polyurethane it should seal pretty well.

It doesn't look too bad either.

[lomdel]

Try adding some closely spaced deck joining lines along the length of that deck. It'll look like real teak decking. major challenge to get the lines spaced evenly. Maybe score them with a scoring tool or blunt knife and fill the small grooves with black paint and wipe off residue... Or just draw them on with a felt tipped fine liner.

[lomdel]

Also read Pat Tritle's article " How to weather model boats " in the Winter 2009 issue of RC Boat Modeller p.52 - 54 for some great ideas to get that scars-of-life look on the battleship.

[Chop]

Okay, worked on the boat today w/my son. Lots of parts put together on the deck. Did some painting as well. Some work on the deck needs to be completed.

The first picture shoes some sub assemblies (the hull, deck and hatch) put together.

Second is a shot of details on the deck and hatch.

Third is a look at the back of the boat.

[Chop]

Lots of the "detail" work is nearly complete.

[Chop]

A couple of concerns here.

1) How far should the prop’s be from the rudder and the end of the stuffing tube?

2) Is the motor location critical? I know that I need to keep the C.O.G. in mind, but as long as I keep it in the ball park I can fine tune with the battery location. This is a 29.5” mono so I should keep it at 27 (7.8") to 30% (8.7") from the transom.

3) Rudders and all connecting hardware is PLASTIC. I would think that I should have new parts made out of aluminum(?) or something else to make them more durable. The penetration through the hull is a plastic tube. If the rudder is aluminum I think that there is enough room to put a sleeve in it so there is metal on metal rather than metal on plastic.

MACHINISTS OUT THERE???

[Chop]

:help:

A couple of concerns here.

1) How far should the prop’s be from the rudder and the end of the stuffing tube?

2) Is the motor location critical? I know that I need to keep the C.O.G. in mind, but as long as I keep it in the ball park I can fine tune with the battery location. This is a 29.5” mono so I should keep it at 27 (7.8") to 30% (8.7") from the transom.

ANYONE???:help:

I'll try to make the rudders myself with K&S parts and solder them.

Pic. shows plastic rudder at top, and what will be the new rudder(s) on the bottom.

[Chop]

Worked on the rudder(s) today. They should be more durable than the plastic ones that came with the kit. All made out of K&S tubing. Also made it small enough that I have a brass sleeve through the hull.

[Chop]

:help:
A couple of concerns here.

1) How far should the prop’s be from the rudder and the end of the stuffing tube?

2) Is the motor location critical? I know that I need to keep the C.O.G. in mind, but as long as I keep it in the ball park I can fine tune with the battery location. This is a 29.5” mono so I should keep it at 27 (7.8") to 30% (8.7") from the transom.

:help:
Come on guy's, just lookin' for a little help here.
:help:

[Viking]

Hi Chop;
Nice job on the rudders, I am still running the plastic rudders that came with the boat.
This was the first project boat my sons and I built 30 years ago. It came with a 400 size motor and some plastic gears to spin both shafts.
I built stuffing tubes of brass and used 1/8" brass rod for the shafts. I put a short piece of 1/8" inside diameter tube in each end of the next size larger tube, and soldered them in place, this drastically reduced the contact area of the shafts in the stuffing tubes. I also added oiling risers so I could oil the shafts. I threaded the end of the shafts and used a counter rotating brass props. I put a nut on the shaft then the prop and another nut and jamed them against each other, this was before nylon stop nuts and locktite.
The props would be quite close to the rudders, you have the motors where I have mine, I built an aluminum bulkhead to mount the motors in and glued it where the plastic bulkhead went.
Good job so far. You can see my PT109 here www.dickieeng.com/PT-109-RC-Model.html
Viking

[Chop]

Thanks for the info Viking.

Since no one else seems to want to help out here, I will take a guess locate the motors so that the props end up as they are shown in the attached photo, about 1/8" from the end of the stuffing tube.

[Chop]

Hi Chop;
Nice job on the rudders, I am still running the plastic rudders that came with the boat.
This was the first project boat my sons and I built 30 years ago.
Viking

If the plastic ones lasted 30 years maybe I didn't have to go through all the work to make mine.:glare:
I must say that I like the looks of mine better though.:biggrin:

[Chop]

The boat is ready for some electronics to be installed.

This isn't going to be a speed boat, but I do want it to go fast. One small thing I can do is to eliminate extra connectors (plugs). All of my batteries have deans plugs on them. By changing the plug on the ESC I can eliminate several.

So that's what I did. I decided to wire in the "Y" harness and get rid of that connection too. BUT I MADE A MISTAKE!! I had a Deans with a wire already on it so I used that as the jumper. Then finished the other Deans then wired back to the ESC.

I hooked everything up, was looking things over and smelled something HOT! Picked up a battery to inspect and could hardly hold on to it!! Unplugged everything and grabbed the DuraTrax thermometer. Temps on the batteries and ESC were about 195 degrees F (91C), and that was after only about 20 seconds!!!

First pic, what I would have to do without rewiring the ESC.
Second, What I had when I was done with the wiring modification.
Third, the OOPS!

[Chop]

Here are some pictures of the inside components.

The motor mounts are held in with servo tape. Is this going to be sturdy or durable enough? I could 'glass them in place. I would need to do that before I glue the deck down.

[Rex R]

personally I would use silicon (aquarium cement) to attach motor mounts if I wanted a semi-permanent solution. servo tape has its uses...but, not(imo) for a possibly wet area.

[Chop]

Eventually, I fiberglassed the motor mounts in place.

I also need to find some brass props. I believe that these are 1/8" threaded ones.

I am still trying to find cloth flags, but for now the paper flags will have to do. Does anyone know of a source for a 2" x 3" American, 48 star flag?

Here is the (nearly) finished product. I will try to get it into the water in the next few days and get a video of it.

[Jesse J]

Great job, Chop! looks great. Poor guys look like they are getting it from all sides... I wish em luck. at least they have some BIG torpedos to send off.

Can't wait to see her on the water!!!

[sailr]

Nice job on the boat! Have you bathtub tested it for a float test? That boat doesn't have a lot of freeboard and if she sits too low in the water it will swamp and sink pretty easy. My son and I built one of these also, about 30 years ago. Problem was with that boat there was one motor driving the two prop shafts. The plastic gears lasted about 30 seconds. My son has had it on his shelf now for all those years.

The PT's were mostly made by Higgins Company in New Orleans. They were almost entirely made of plywood. This made them cheap to build and also allowed them to be really light weight so they were a fast boat! I visited the Higgins factory in 1960 before they went out of business. My Dad had an 18' runabout made by them with a Ford Interceptor v8 in it. It was a rocket. Over 50mph. We loved that boat! It was all plywood also.

Keep us posted. Post a video if possible when she is running!

[sailr]

The servo tape isn't going to hold the motors I'm afraid. I'd use some silicone glue or gorilla glue. F'glass cloth with epoxy (don't use polyester resin, it will eat the plastic hull!) would work too but you'd need to scratch up the hull to give the epoxy something to grab onto.


Here are some pictures of the inside components.

The motor mounts are held in with servo tape. Is this going to be sturdy or durable enough? I could 'glass them in place. I would need to do that before I glue the deck down.

[Chop]

The maiden voyage was successful!!! I need to adjust the rudders a bit, it doesn't want to turn right as well as it turns left, but that's minor.
Video, as requested:
http://www.youtube.com/watch?v=Aqx7aF4VH8M
Get a load of this: there is a dragonfly in the lower right corner of the last picture. Is it on a strafing run?

[wolf IV]

Great looking boat!!! Love the pics but thevid link is inop..

[FastVee]

I belive this is the correct video?
http://www.youtube.com/watch?v=Aqx7aF4VH8M

[sailr]

The boat runs great! Nice job all around. My son and I built one of those same kits about 25 years ago. We weathered it, gave it some battle damage, etc. The first time we ran it the plastic gearbox crapped out. It is now a shelf queen at my son's house!


The maiden voyage was successful!!! I need to adjust the rudders a bit, it doesn't want to turn right as well as it turns left, but that's minor.
Video, as requested:
http://www.youtube.com/my_videos_ed..._id=Aqx7aF4VH8M
Get a load of this: there is a dragonfly in the lower left corner of the last picture. Is it on a strafing run?

[Chop]

I belive this is the correct video?
http://www.youtube.com/watch?v=Aqx7aF4VH8M

Thanks FastVee, that is the correct link.

[wolf IV]

got it, awesome.!!!