ears1919

After looking at one of the artwork hanging in the workshop, decided to recreate the scene.

Its pencil artwork by Rene Gannon showing Higgins engaging with S-Boat....

ears1919

On the Higgins, decided to go with Peter Miller's free plan from August '04 issue of Model Boats magazine after seeing couple builds by others based on this plan...

Tried to find a copy of August '04 Model Boats magazine without any luck but found the article online and obtained .pdf copy of the free plan that was included with that issue...

Shown is what I printed from my computer and took the .pdf file to Kinko's to have them print me a copy on their plotter in full scale, cut out all the ribs templates. (Made 2nd copy of all templates to keep in my files)

ears1919

On the Schnellboot, I have old unbuilt Accuscale (Formally 32nd Parallel) Schnellboot kit but wanted to build wooden hull along with Higgins...

Needed Hull Lines and the Accuscale Plan doesnt show any Hull Lines, I was going to copy the contours of the fiberglass hull from the kit but luckily found a plan showing top view, side view and all hull lines that I need. Its in 1:50 scale so I'll have it scaled up to 1:32 scale to match the 78' Higgins.

Shown is the Top Views of both Higgins and Schnellboot next to each other in 1:32 scale (Miller's and Accuscale plans) and the last two pictures are of the 1:50 plan that I'll be using as reference for the Schnellboot...

ears1919

Size comparsions:

78' Higgins - 29.25" Length in 1:32 Scale

Schnellboot - 43.125" Length in 1:32 Scale

At first on the paper it seemed to be in similar sizes but in the last post where top view of both Higgins and Schnellboot are side by side. Now thats a bigger difference than I was expecting...

*Note*
This build thread would be in 1:32 Scale but while I'm doing the template works, I wanted to have 1:20 Scale later in the future so thought I'll save myself time and do both templates in 1:32 and 1:20 now. On the paper it shows that I need to do 160 percent enlargement off 1:32 templates to get 1:20 scale which I'm doing off Cannon Copier that I picked up for myself couple years ago.

Higgins: 46.8" Length (1:20)
Schnellboot: 68.8" Length (1:20)

Shown is the difference of Higgins Template #1 in 1:32 and 1:20 Scale...

martno1fan

Hi mate glad you got the plans ok ill keep an eye on your progress,id like to build a larger one myself some day.Been too busy building my glass hulls for gas motors,mainly vees and hydros.Love the scale stuff though so one day ill make a bigger higgins.Good luck with your build .
Mart

ears1919

On the Higgin's plan - It shows that the author used 1/8 balsa for the bulkheads which I prefer to make the bulkheads out of 1/8 ply instead. There's many methods of making bulkheads straight from the plan such as using carbon copy (messy), 3M77 glue spray (also messy), etc...

Here's how I did with mine (Only showing how I made bulkhead #1)

1) Cut out all paper bulkhead templates with scissor...

2) Laid on 1/8 ply and marked dash lines all around the template... (Note: Its easier to do dash lines rather than trying to make solid line all around without moving the template in middle of tracing.)

3) Connected all dash lines... (Note: Dont forget to mark centerline and bulkhead numbers on it to make it much easier for yourself)

ears1919

1) Using scroll saw - Stay 1/16" outside of the line all around then cut the stringer slots right on the line. (Easy to be precise with the stringer slots since its only 1/4" sq)

2) Showing the overall view of the rough work with Bulkhead #1...

ears1919

Sanding the rough-cut bulkhead to the line....

1 down - 9 more to go...

*Note: Left the keel notch uncut since havent decided yet on what to use as keel and want to be sure its a tight fit between bulkhead and keel so will be using the actual keel to mark the slot on the bulkhead.*

fokker fan

How's the Higgins coming along?

ears1919

Fokker ~

Higgins has been going along VERY slowly due to work and wasnt sure if anybody beside Mart watching this build thread...

Managed to put little time on the Higgins but didnt update the build thread until you chimed in so I'm updating it now...

(Work is due to slow down a little starting in Sept so would have more time to hit the Higgins build)

ears1919

Update:

1) Marking the openings on the bulkheads - Showing progress with #5 bulkhead here
(Shadded the area to show what will be removed)

2) Drilled the starting point for the scroll saw...

3) Didnt cut out the cross hatch since will be using Jig to assemble the hull, marked the cross hatch with dashed line for me to hand cut out the hatch after the hull is sheeted and safe to remove from the jig. (Note: extended the cut outside the opening up to the dash line - circled area as shown in the last picture)

ears1919

How the heck the last set of pictures are so huge unlike the previous pictures????? []

fokker fan

I just discovered this thread yesterday but will be watching now. I have the Peter Miller plan and construction article also, and would like like to build it at double size (53.5") for a gas motor. I have a Husqvarna 32cc sitting around looking for a home and always liked the US PT boats.

BIKERBOBW

I am new to the forum; but will watch with interest your build as I too am about to build a Higgins .

The PT boat is at a scale of <st1:time hour="13" minute="20">1:20</st1:time> so therefore will be about 48” long and guessing at a finished hull weight of 2 lbs .I am hoping to get it up on a plane and a run time of 30 mins. Is this run time achievable and realistic?

I am considering Gaupner speed 600 or Astro marine 425 motors running on 12 volts each; with all 3 running forward and only the ctr capably of reverse. Will these motors achieve my desires or will smaller motors work?

What would you recommend for batteries Gel cell or NimH cells? If NimH how should the pack be built to achieve the run time; 10 cells in series = 12 volts but how many in parallel to achieve run time?

Finally can you recommend a ESC that can handle the above? Will I require a ESC for ea motor?
Awaiting your thoughts

fokker fan

A Higgins at 1:20 scale will be 46.8 in long and will displace 11.74 lbs at the scale waterline. In order to achieve a displacement of 2 lbs at the scale waterline you'd need to build it at 1:36 scale (26 in long).

The original engines were rated at 3600hp each x 3 engines. To achieve the same sort of full speed performance at 1:20 scale (11.74 lbs displacement) you will require 3 motors of 335.7 watts each - at 12v that's 27.9 amps each x 3 motors = 83.7 amps. To run at full speed for 30 mins will require a 12v 42 Ah battery pack or to put it another way 175 1.2v 2400 mAh cells wired in series and parallel. Of course you wouldn't run at full speed for the full 30 mins would you? So you could settle for a lower current rating in your battery pack and therefore less cells.

To achieve the same sort of full speed performance at 1:36 scale (2 lbs displacement) you will require 3 motors of 57.6 watts each - at 12v that's 4.8 amps each x 3 motors = 14.4 amps. To run at full speed for 30 mins will require a 12v 7.2 Ah battery pack or to put it another way 30 1.2v 2400 mAh cells wired in series and parallel.

The problem with electrics is that to obtain good planing performance and endurance requires a large power source and a large power source is heavy which in turn reduces performance. So, generally you can have lots of performance and little endurance OR lots of endurance at displacement hull speeds (ie no planing). There is a 3rd option if you have deep pockets - use brushless motors and LIPO or A123 batteries as used in model aircraft. The brushless motors are powerful and relatively efficient and the batteries mentioned are lightweight but with good power outputs. You will also require speed controllers that are designed for these motors and a battery charger designed for these batteries.

Or you could just put a gas motor in it and plane all day

ears1919

Fokker ~ Thanks for the tech info's by answering BikerBob's post.... Interesting!!!!

I'm much more simplier - such as swaping motor sizes, batteries, prop sizes until I achieve what I was looking for. Learning by trails and errors is FUN!!! (Looking at other person build and their selections gives me a general idea on where to start)

In obtaining longer run time without spending truck load of money on high performance batteries/chargers such as lipo's, would suggest looking into gearing the drive train to keep the motor running cooler and extend the running time. Gearing would draw less amp and give more torque, probably would be the best answer beside having to get couple battery packs and swapping them out every 10 minutes. (Just my opinion)

ears1919

I'll suggest to go to Pat Matthew's website....

Go to www.matthewsmodelmarine.wordpress.com

and look for article titled "All Geared Up"

WONDERFUL ARTICLE!!!!!!

martno1fan

Im still watching m8 keep up the good work .
Mart

ears1919

Starting on the Keel....

Looking at the plans, build articles and other's build ~ Noticed that the keel extends past the hull and the bottom planks are butt against the keel, sanding the keel profile after the planking to match the profile. This method is different from what I'm used to and will try this method with this build instead of planking over the keel as usual.

1) Plans showing the keel's around 5/8 inches wide plus/minus 1/16 - 1/8 inches in different spots as shown on the plan. So decided to cut the keel 3/4" wide to work with. (1/4" thick)

2) Got 1/4" thick balsa sheet to cut the keel out of. Note, balsa sheets almost never have a true straight edge in my experience. See in the picture below how much its bowing when butt against a straight edge.

3) Cutting off about 1/8" using straight edge. Other way is to sand the edge but only need to do one sheet so this way is much quicker...

4) Now checking the edge and its true to the straight edge...

ears1919

Master Airscrew Balsa Stripper is one of the best tool I've been using....

1) What I do is to set the depth about 1/32" - 1/16" below the surface and also the width to 3/4"

2) Since my workbench surface is particle wood (Too much drag on the Balsa Stripper) - I put down two pieces of balsa wood under the stock. (leaving space between the cutting line for ease in cutting)

DONT FORGET TO USE THE EDGE THAT YOU JUST MADE TRUE!!!!!

herrmill

I've bookmarked this one as it will be a good thread to follow.

FYI, there's another Higgins build using the same plans over at Modelboatmayhem.

ears1919

Thanks for the heads up Herrmil, now I got to go over to Model Boat Mayhem site and see if I can find that thread you're talking about....

ears1919

Finally found some spare time and here's how I use them...

Finished with the Keel - Didnt cut notch for the stuffing box because wasnt sure if I'll modify the angle of the shaft. Looking at other's builds of this plan, see people saying the angle is a bit steep plus going to start with direct drive but if motor's running too hot or the run time is way too short then would be swapping for geared drive. If I lower the shaft angle then I'll have more room to install geared drive. (Just covering my bases)

ears1919

Building the JIG....

Author's (Peter Miller) build article simply said "Build the Jig" without any additional info on how to do it and looking at other's build which doesnt show how they made their jig either....

So had to come up with my own way and am showing it how I did it step by step here. (Comments or Suggestions on better/quicker way other than mine is WELCOME to post here)

#1. Finding my own "Datum" line, wanting to have bottom of the hull parallel to the jig. Keel between F3 and F8 is straight so chose to use that. (Pic 1)

#2 Using 3 1/2" wide by 1/2" thick Popular wood board as Jig material. (Pic 2)

ears1919

After Marking Datum Line on the plan, next is to figure where to put the JIG....

Since the Jig Board is 3 1/2" wide - selected 5" from the keel to give me ample spaces to cut the slots for the bulkheads. (Pic 1)

Using the Jig Board itself and line it up with the Jig line that I just made to mark the top of the Jig on the plan. (Pic 2)

Plan showing three lines to use as reference point on building Jig, Bottom line is Keel line (Datum), Middle line is top of the Jig, Top line is bottom of the Jig. (Pic 3)

Last check to see if the Jig is acceptable before cutting the Jig Board. Placed Keel and Bulkhead #3 and #8 on the plan. (Pic 4)

Looks good to me so far...