MAS-Torpedo 210cm 35cc x 2 FPV
 

Hello to all the model makers!

We are two Italian boys from Milan. We wanted to combine our passion for model making, boating, engines and technology in general.

The project we are carrying out is a boat (which will then be remotely piloted long range FPV) built for long distances at geande speeds. The will will be to be able to make a crossing or record by participating in unique events. (For example, 100 miles offshore on Lake Como, for real motorboats, see below for this presentation).
The hull must be very reliable, the engine powerful and reliable and the average speed to be able to keep very high (hopefully in 80 km / h, 50mph / h)

In this post we will write about the construction of the boat, entirely designed and built by us:

https://www.rcuniverse.com/forum/spe...cc-x2-fpv.html

Write there!!!!

The hull is a fusion between the hull of an Italian MAS, a PT torpedo and an American Hatteras, 210cm long.
Cortuito with internal truss in marine plywood (7mm), and the entire hull with balsa (4mm)with various reinforcements. The entire hull is covered with fiberglass and epoxy resin fabric. The hull has 6 layers of 160gr/mq, the side parts 4 layers of 160gr/mq, the deck 3 layers of 110gr/mq.

The motorization was a difficult choice.
the first option was an SG 35cc engine with splitter for counter-rotating propellers ... we then opted for a 62cc Honda always with splitter for counter-rotating propellers ... in the end, we opted for double motorization: two powerful Italian MATHE 35cc counter-rotating engines (9hp) each equipped with a centrifugal clutch. Each engine will be cooled by a double cooling system: one with a vacuum pump and one dynamic, the water will finally be injected into the final part of the drains acting as a soundproofing (we are assessing the absence of silencers). The collectors, the expansions and the entire exhaust system will be hand-made to measure to increase the performance, it will be all wrapped with bandages and fiberglass fabric and then covered with ceramic paint.
The transmission will be in the center line with a 5mm jacketed and oiled carbon steel rod with a drop system (as on FSR-V competition boats), double immersed and sharp steering system.
Choosing propellers will be hard work.

The fuel tank will be unique, approximately 5 itri (theoretical). with rapid remote refueling system; with a capacity of 5 liters the hull will have an autonomy of about 30 minutes at maximum speed (each engine consumes 1 liter in about 12 minutes).

Expect many questions from us ....https://www.rcuniverse.com/forum/ima...ilies/wink.gif



Among the friends who advise us in this undertaking is Paolo Gualdi (world champion 5 times in FSR-V 27cc and 15cc)
He himself completed 20 years ago with his friend a huge and difficult test: the Offshore Raid Pavia-Venice with a 15cc hull, 8.5 hours at an average of 41.7mph / h to make 355 km. below the history of the company ... translate it with google which is very interesting!
Gruppo Modellistico Belgioioso

Sounds like a very cool project!! Look forward to seeing it come together!

Hi Justaddwata
Thanks!!
I'm going to move this discussion to "speed - gas boat" in a short time.!!!

And here are the first photos of the hull (without deck)!!

The construction of the hull, for structural and ptratic reasons (assembly of mechanics and hardwear) was divided into three phases:

1- Hull construction and walls. Radio compartment construction. Engine arrangements, propulsion and steering system. Installation of the exhaust system. Cooling system arrangement. Electrical system arrangement. Fuel system arrangement.
2- Widening of the upper part of the calico. Structural reinforcements for complete deck. External covered profile construction.
3- Complete covered construction.


Here we are at 25% of phase 1.
In PHOTO 1 you can see the complete hull (actually still to be finished in this photo), as it will be for this whole phase, divided into 5 compartments: 1 will house the radio compartment, 2 will host expansions, tank and axle output, 3 engine compartment and upper cabin with future chamber and FPV system (insulated) 4 and 5 empty with floating filling.
The length from bow to stern is 210cm. The maximum width is 45cm.
The internal truss in marine plywood (7mm) laser cut from a single sheet of marine plywood of 260x120cm. The laser cutting is extremely precise but all edges MUST be sanded in order to take away the laser burn and be able to work. The CAD rendered drawing, the cut (which lasts depending on the material and thickness of the same) in our case lasted about 35 minutes. Each piece is assembled by gluing with epoxy resin and nailing with 6x2mm brass tacks (one every 6mm apart)

The primary interior of the hull is made up of balsa tablets (4mm) placed perpendicularly. In turn reinforced by balsa strips 4mm thick x 10 wide at a distance of 3cm from each other. These strips are then reinforced by a double transversal strip always 4x10mm (PHOTO 2) each pair of transversal reinforcement strips is finally covered by a last layer of 2mm balsa. (PHOTO 3). All this procedure is by gluing with epoxy resin and nailing with 6x2mm brass nails. Final result e.g. PHOTOS 4 and 5.
This lack of reinforcement even in the middle of the side member will not be done in compartment 5 as in addition to weighing down the bow it would be superfluous for two reasons: the section is shorter than the others and twisted, this gives a natural resistance more than the sides of the previous sections ; another point because there are the intersections between the fiberglass coverings of the hull and the bulwarks, which offer considerable resistance. (PHOTO 6)The entire hull is covered with orthogonal textured fiberglass fabric and epoxy resin with the "wet on wet" technique.
The hull has 6 layers of 160gr / m2, the side parts 4 layers of 160gr / m2, the deck 3 layers of 110gr / m2. (I will put time lapse reeds if I manage the hull cover phase)

Detail of the bow, finished (missing the final calyx of the upper part that "connects" to the deck (Phase 2) (PHOTO 7)

To test the resistance of the hull we built a section of the hull to test its resistance.
The result is a high resistance to twisting but at the same time elasticity. High impact resistance. (repeatedly hammered hard with square head of the hammer and no damage that could compromise navigation.


Thing not to underestimate absolutely: the weight. So complete and coated hull weighs 5.5 kg. We estimate a final weight of the complete hull (hull only) of 8.5 kg. Complete in order of navigation, empty tank, of 18kg; with a weight / power ratio (Kg / hp) of 1/1.https://cimg3.ibsrv.net/gimg/www.rcu...7d73eb977c.jpg
Foto 1
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Foto 2
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And here is the most delicate construction phase.
Positioning and fixing of engines, axles, rudders, hull float filling, main water intakes and carburettor linkage.

In this post the construction of the axles, rudders and main dynamic water outlets.
In the next, the most complex, the positioning of the engines (positioning of the construction, axle supports, positioning of the rudders and water outlets, fixing of everything).


And here is the most delicate construction phase.
Positioning and fixing of engines, axles, rudders, hull float filling, main water intakes and carburettor linkage.

In this post the construction of the axles, rudders and main dynamic water outlets.
In the next, the most complex, the positioning of the engines (positioning of the construction, axle supports, positioning of the rudders and water outlets, fixing of everything).
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Motor positioning (with base construction and support brackets), axle positioning, rudder and water intake positioning, fixing of everything.


Photo 1. Hull drilling and construction of engine support brackets base.
We were forced, of course, to puncture the hull along the axle exit (it was not easy given the resistance) and then subsequently pass the axles. The base construction of the motor support brackets was made by connecting with a 7mm thick plywood board subsequently reinforced by crosspieces that rest directly on the hull, all resin-coated and covered with a layer of glass fabric 110gr / m2. The empty spaces filled with high-strength dense polystyrene blocks (green color, can be seen here even before the positioning of the plywood which will serve as an internal anchorage of the boards, clearer in the following photos), the additional empty spaces filled with epoxy resin mixed with hollow fiberglass microspheres. Note the lateral cut in the engine compartment to make room for very large clutches.

Photo 2. Positioning of motors and axes equalization system.
More complicated and delicate part. The motor supports will be arranged and anchored (provisionally) to be perfectly in line and parallel between them and having the same inclination.

Photo 3. Positioning and fixing of the motor support brackets and of the axes.
As mentioned in Photo 1. last post, the boards are anchored by means of a completely resin-coated steel bracket and fixed to a table top in marine plywood. (see next post for details). The engine brackets are built with 3mm inverted L steel. Here you resinate definitively in the final position also by riveting. They will then be fixed with two dedicated layers of 110gr / m2 glass fabric for each bracket. Note the corrugated profile to keep the motors in width and the replacement, as already mentioned, with high resistance polystyrene, microspheres and reinforcement epoxy resin.

Photo 4. Motor compartment filling and stirrups reinforcements; carburettor linkage passage.
The whole hull area of ​​the engine compartment has been filled with pressed closed cell polyurethane foam (by closing the compartment beforehand and spraying the foam and then drying it, reopen it for modeling). Note the internal passage of the linkage for the two carburettors. The cables of the latter pass inside reinforced tygon tubes and connected to parts of the hull in order not to deform the curvature. This is to be able to have as few cables as possible around the hull and have everything tidier. The cables are 2mm steel braid, the 4mm reinforced tygon pipes.

Photo 5. Grouting and total reinforcement fabric.
Further finishing of the engine compartment, grouting with the now friendly paste of hollow microspheres and epoxy resin. The shapes accompany those of the crankcases of the two engines.
Another step is the laying of a last layer of glass fabric (110gr / m2) to make everything more compact and resistant, isolated and orderly.
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Grouting and total reinforcement fabric.
Further finishing of the engine compartment, grouting with the now friendly paste of hollow microspheres and epoxy resin. The shapes accompany those of the crankcases of the two engines.
Axis area.

Photo 1. Axis and motor alignment.
As in the previous photos, note the aligned positioning of the axis motors. Particularly you notice how the axles are anchored to the hull (where we had previously made the "hard base" made from 0.5-2cm thick glass fiber psta on the whole hull, equalizing the bottom.) Filling the axle output with fiber paste glass and epoxy resin.

Photo 2. Detail of the positioning of the first pieces of glass fiber fabric (110gr / m2) on the various supports.
They will be positioned twice with the "wet on wet" technique.

Photo 3. Detail of the hull and axle exit.
Perfectly aligned and with measures equal to those desired at the start. In particular, all the filling work with fine fiberglass putty paste (no microballs here but glass fiber putty and epoxy resin with high mechanical resistance)

Photo 4. Detail of rudder positioning. (they will then be sharpened from the direction of the hull, towards the bow).
Detail of the water intakes, as said in an optimal position so as not to get in the way creating further hydrodynamic resistance and to have greater efficiency for the flow of water which, in addition to being dynamic (given by the movement of the hull), will be amplified by that coming from the flow of propellers.

Photo 5.Final overall view.
(In reality, we then re-assembled everything for the arrangement of the carburettor linkage which is still missing in this one)



For convenience and ease we have illustrated the stages of construction by dwelling on divided parts, it would have been extremely difficult to explain everything in the overall view.
From now on the most mangy phases from the point of view of precision are all downhill. This phase was the most delicate, the success of the project all depends on the greatest possible precision.


The next steps will be to fill the hull in compartment 2 (so as to completely incorporate the carburettor linkage and the axles) by means of high-resistance polystyrene, hollow microballs and epoxy resin (by now it has been understood); the creation of compartment 1 completely stano; the water intakes for the pumps; servos positioning; etc. etc. etc.

P.S. The photos taken were many more, we uploaded the most significant ones. For the "covered" section we will try to load them on an external drive; unfortunately the available memory is not editable. We take this opportunity to thank the Forum Administrators, very kind and very quick in replying

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Wow thats quite the little ship!! Lots of great work!!

Hi, Justaddwata!

ahahah why "little ship"?!?! :DIt is totally handcrafted (as on the FSR-V competition hulls of which it has followed the mechanical setting). The development of the project is for the success of a precise final target.
we will have many questions and we hope to arouse the curiosity and interest of many people!

Little ship as she is such a large looking model. Looks great. I cannot say I have seen a build quite like this. Large wooden scale PT boat styling with twin gas. I think you will see a lot of interest!

I have an old wooden model I purchased used. It was powered by a Quickdraw 70cc motor. I purchased the boat to use the motor in another project and may someday repower this boat with a blata clone. https://imageevent.com/justaddwata/m...customrunabout

I also have a large MHZ model that is heavy - not sure the weight but it is probably 30kg or so. Powered by twin CMB35 RS motors. Only limited run time. I would estimate 60mph capable though have yet to make recordings and final trim adjustments. https://imageevent.com/justaddwata/m...kacanoerepower

The design of this hull is particular: it must be fast, resistant to be able to face high waves (50cm) without problems.
This is because we would like to do both a race (100 miles of Como, for real Offshore), and a record of marine navigation (much more than 100 miles).
The safety of the double engine and the resistance of the hull helps. In addition also a large tank. As you could see in the initial photos it is all built by hand and designed by us, the deck will be very different from the PT or MAS in order to have the best performance at sea. In the future I will most likely also be piloted in FPV.

Going back to construction, the absolutely hardest thing to find will be the propellers.

Were very impressed by the hull with two CMBs, 2.66cm and 60mph with twoCMB35!??! think .. I had seen photos of this model many times .. and now I know who did it !! hahha The one with the single Blata ... is exaggerated! haha I have several questions to ask about cooling pumps !!



pswe hope that this project will arouse the curiosity of many people!

Weekend job.

It is not much but in the week we plan to be able to complete the radio compartment, therefore the whole first compartment. Being able to work together in this period is complicated..someone does something that leaves in the "laboratory" and in turn it goes to complete what the other has suspended in, sent in details in videochat and sending drawings or inserted in videochat during construction , without seeing yourself in person ... maximum safety but maximum slowness (I can imagine the delusion of the previous construction)


in any case ...
Photo 1. Detail of the tie rods for levering the carburetors.

Photo 2. Detail view of the passage of the carburettor linkage passing through the bottom which will be filled with polyurethane foam in a closed cell and reinforced with glass fabric.

Photo 3. Overall view of the completed filling work (sanding of the surface and the drafting of a glass teeuto of 110gr / m2 are missing.
We used a resin / microballs / fiberglass paste different from section 1 (the dove is fixed to rudders and rudders, it is much more resistant there (microball 3% -97% paste of glass fiber and resin. Opted for two central polystyrene longitudinal beams immersed in closed cell polyurethane foam for the empty spaces in the center of the hull while for the mixture of microball and fiber paste (50% -50%) for the part slightly around and above the axes (this procedure is done for obvious needs before filling with polyurethane foam.
This is to further burden the hull and at the same time create a floating reserve.
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