Model Boat Mayhem

Mess Deck: General Section => Beginners start here...! => Topic started by: pompebled on November 27, 2011, 03:02:37 pm

Title: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on November 27, 2011, 03:02:37 pm
As promised, some pictures of my M.A.S. build.

I bought this plan some 15 years ago:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture78032-kleine-ashoek.jpg)

Having no experience with building from scratch/plank on frame, I started with a small version made out of cardboard.
This 75 cm long hull was then covered in candle wax and covered with glassmatt and polyester, working with the left-over material at my work at the time.
This resulted in a bomb proof hull, which I used as a test platform for various motors, from a geared down 05 car motor on 7 cells NiMH to an 900 motor on 12 cells NiMH:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88475-mas-75-cm-01.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88476-mas-75cm-02.jpg)

You see I abandoned the two shaft set-up from the start, as a single large motor and prop is more efficient that two smaller ones, having a minute budget also had to do with it

Having goofed around with it in the local marina, the hull proved very fast on 12 cells and very nimble on 7 cells, but too heavy to carry a deck and superstructure without looking as if it was on the edge of sinking...

Together with my son, who started in the hobby around that time, running my boats, lacking one of his own, we started out building two of these boats, slightly bigger to avoid weight issues.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88473-spanten-110-cm.jpg)

The picture shows the present state of my son's build; after he'd gotten this far, running FE got his attention and pretty soon the both of us were racing our boats in the National competition.
Needless to say that building and maintaining a fleet of FE boats and battery-packs took a lot of time, which took it's toll on the M.A.S. build.

I kept working on mine every now and then and eventually the hull was sheeted but for the bow section:

The transom was easy:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88472-hek-110-cm.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88305-mas-110cm-02.jpg)

Notice the camera angle, (almost) not showing the unfinished bow...

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88304-mas-110cm-01.jpg)

As I used the cheapest and lightest ply I could find, the 3,2 mm poplar ply was not just very soft surfaced, but also very reluctant to bend around the bow section, so I had to work around that:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture77681-boeg-110-cm-03.jpg)

The sheets and stringers ended at the first former and I used 6 mm ply to extend the lines of the stringers, giving a hold for the strips of poplar ply, which were sanded to fit snugly next to each other, forming the curvature of the bow section.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture77683-boeg-110cm-02.jpg)

The top view shows, my accuracy on the curve wasn't too good at the time.
I left holes, so the interior could be waterproofed with epoxy once the bow was closed.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture77682-boeg-110-cm-01.jpg)

In this shape, the hull sat on the shelf for a number of years before I had time to work on it again, between moving to another house and racing six sundays a year.

Next was sanding and glassing the hull.
As I had changed jobs and working with polyester had made me allergic to the stuff, I chose glasscloth and epoxy, far less smelly and it didn't trigger an allergic reaction.

I started with glassing the transom and the steps, once this had cured, I moved on to the sides.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture87697-glass-epoxy01.jpg)

As I wanted to keep all edges sharp, I made templates for the glasscloth and cut the parts with a very small overlap, so it wouldn't bend over the edges. Once cured, I cut the overhang with a sharp (razor) blade and used sandpaper for the rest, carefully watching not to sand through the glasscloth.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture87698-glass-epoxy-02.jpg)

Once the glassing was done, I added two thin layers of epoxy to cover the weave of the glass; as I had to work in sections and sand and degrease prior to every coat, this took the better part of a week, one flat surface a day.

Now the hull looks like this:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88073-glass-epoxy-03.jpg)

The rough patches is where I sanded through the glass, exposing the wood, so a few sections were re-done with glass and epoxy.
A close up:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture88074-glass-epoxy-04.jpg)

This has been sanded last week and covered with a final layer of epoxy.

Once the epoxy has fully cured, I'm going to do some tank tests to establish the position og the motor, propshaft and batteries.
As the hatches are very small, access will be an issue once the deck is in place, I'm thinking of making a larger section of the deck removable...
Next is filling and sanding before the first coat of paint.

Regards, Jan.

Title: Suggestions please (access issues).
Post by: pompebled on November 29, 2011, 06:37:48 pm
Hi all,

As my intended testtank turned out to be too small, I have to resort to lying on my belly at the canal near my house...
The weather hasn't been favourable lately for (outdoor) balance testing, but I have the suspicion, the access to the interior of the boat will be a major issue, as the superstructures are very small.
I know from my 75 cm model that the weight needs to be very far back, the batteries were against the transom, with the deck in place and the 'gooddies' of the depth charges and ammo cabinets in place, this could be a major problem.

I need some suggestions how to realise a (much) larger hatch, so I will be able to work inside the hull after the deck has been put on.

I'm even considering to make the entire deck removable, like the Italeri kit, but having a lot of screwheads on the deck isn't my favourite solution to be honest...

Your ideas on the subject please.

Regards, Jan.

Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: MikeA on November 29, 2011, 07:04:50 pm
jan i thought you was a boat building master!!! Maybe i can help you this time in return for all the times youve helped me. i made the hole first then put a lip underneath the deck so the the hatch is level with the deck:

(http://s7.postimage.org/j4aeogj87/DSCI0369.jpg) (http://postimage.org/image/j4aeogj87/)
 
the rear deck fits into over the gap:

(http://s12.postimage.org/j6o80agux/SDC11773.jpg) (http://postimage.org/image/j6o80agux/)

the wheel house has a petruding bit on the bottom which locks into the motor acces hole:

(http://s7.postimage.org/4pfgm9p3r/SDC11774.jpg) (http://postimage.org/image/4pfgm9p3r/)

and the wheel house holds down the rear hatch:

(http://s8.postimage.org/wxfu02hi9/DSCI0132.jpg) (http://postimage.org/image/wxfu02hi9/)


Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: MikeA on November 29, 2011, 07:22:28 pm
from the look of the plan the deck seems flat, If so then its possible to cut a hole in the deck from the very rear just enough to gain acces to the steering linkage right forward to the front of the wheel house. make the hole wide enough to that the torpedo launchers are also on the removable deck. if your really clever you could possible fashion the torpedo lauchers as twist locks for the deck. if you look towards the bottom of this build thread ukmike has made this fantastic seal:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=31896.200

I think you could possibly make something like this to go under your main deck.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on November 29, 2011, 08:59:47 pm
Hi Mike,

You can call me a lot, but not a boat building master..., I do my best.
My 'core business' has been fast electrics over the years, (semi) scale building is a 'part time hobby'.

As I've learned from the 1/35 scale kit thread, the deck isn't flat, it is curved.
Making a detachable section in that is a substantual undertaking, which involves a lot of tinkering and building time.

A removable deck would mean formers to get the curve right and rigid and light enough, I've even though about making a mold, to make a glass/epoxy deck & superstructure, but at my current build rate, that would set me back another decade before I could hit the water with it...

I hoped somebody would offer a less time consuming way to go about it.

I've been digging through a lot of building threads over the years and I've done my share of mold making and woodwork, so the skill is there, I'm just lacking time (aren't we all?).

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: MikeA on November 29, 2011, 11:08:55 pm
I was just thinking while offline how making twist lock torpedo tubes is a task i wouldnt even consider undertaking myself. I was going to say that if you make the large access hatch as i explained then to fit a lip under the front of the hatch near the wheel house, then use the rear machine gun turret as a bolt head, and screw the back of the hatch down. An m4 bolt would do it, with a captive nut built into the boat frame. I know what you mean about formers as i used them on the original FE i made, if you look at my boat u can see the lip to which fits under the deck and the formers to hold the curve in the deck:

(http://s12.postimage.org/50zmjo9uh/DSCI0698.jpg) (http://postimage.org/image/50zmjo9uh/)

i made the formers by using my chine templates and outlining the top curve of the chine onto ply. then simply stuck them onto the bottom of the hatch cover.

I would presume that you havent got the deck on yet. judging by the plan and what youve told me i dont think it would take anymore time build one large access than it would 2 or 3 small ones.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on November 30, 2011, 08:46:57 pm
Hi Mike,

Thanks for thinking along!

Your fishing boat is about half the size of my M.A.S., so the hatch(es) will be considerably bigger and will need more support to be rigid enough to be watertight with your suggested lip construction.

From testruns with the 75 cm hull, I know the boat runs dry in calm conditions, but in chop the spray flies all over the boat, so a leaky hatch isn't an option.

If the weather holds up I'll go testing the weight distribution, and use that outcome to determen which way to go, hatch/deck wise.

I'll keep you informed.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: MikeA on November 30, 2011, 09:50:02 pm
If you make the hatch stiff enough and use a rubber seal like that on uk mikes boat i dont think youl have anykind of leaky hatch.

i drew this cross section of a the hull and hatch. you will be able to get a rubber seal that goes around a ledge. kind of like a door rubber.

(http://s11.postimage.org/8cfju0frz/hatch.jpg) (http://postimage.org/image/8cfju0frz/)

heres some seal:

http://www.ebay.co.uk/itm/RUBBER-EDGE-EDGING-TRIM-1MM-2MM-U-CHANNEL-KIT-CAR-/170622189434?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item27b9dfff7a
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 04, 2011, 10:13:20 pm
Well, in between the downpours I managed to get a few testruns done to establish the balance of the boat today.

My 'testrange' is the canal near my house:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89252-testrange-01.jpg)

I secured the motor in it's position with some string and positioned the batteries all the way back, so the CoG would be at 30%:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89253-batteries-back01.jpg)

It looked ridiculous and made to boat ride with the nose up:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89254-batteries-back-02.jpg)

So it was down on my knees again to move the batteries forward:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89255-adjusting-balance.jpg)

That looked a lot better, so off I went to the end of the jetty:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89256-running-out-line.jpg)

Getting the boat to line up was tricky as it blew half a gale:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89257-lining-up-boat.jpg)

After having rolled out about a hundred metres of one of my kite flying lines, I was ready to go:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89258-ready-set.jpg)

Go!
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89259-go.jpg)

And catching out the cameraman, as with spooling up the line, the boat came rapidly closer to the shore:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89260-up-close.jpg)

Thanks to my daughter for taking the pictures, she also made a few movie clips, but those need some editing before I can show something, the quality is poor, so maybe I'll get a real video camera next time.

I'm pleased with getting the balance at least half way right, next is installing the drive train, to see if the boat runs similar under it's own power, hopefully a bit quicker, as there's a limit to how fast you can reel it a kit line...
I'll have to wait for less wind to go testing without a deck, as there was a substantual amount of water in the hull after a few test runs into the wind, fortunately only the batteries and the motor were on board.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: MikeA on December 04, 2011, 10:31:46 pm
looks like  nice place to sail
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Daemon on December 05, 2011, 01:15:33 am
scotchkote the servo boards and motor terminals, and just get a watertight box for the battery and rx, works wonders.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 05, 2011, 06:36:12 am
looks like  nice place to sail
Hi Mike,

At this time of the year there's lots of room to run my boats, but in summer it's a different matter; lots of boats moored at the jetty and the other side of the canal, making it effectively narrower, which can be a challenge when I run my fast electrics, as turning at speed can be a hairy experience...
I've lost several 'noses' over the years, but have always been able to retrieve the boat and repair the damage.

@Deamon; I have no intention to swamp the electronics, the boat will have a deck, eventually (see top drawing) and be watertight, keeping the internals dry, even when the spray flies over the deck.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Daemon on December 05, 2011, 09:43:44 am
Okidokes, just a precautionary measure I take on some of my yachts, thats all...

Looking good, though, keep it up!
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Norseman on December 07, 2011, 11:48:56 pm
Hi Jan

Thanks for posting the pictures of how the bow is formed - I didn't know that and it was a nice little lesson for me :-))

Dave
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 08, 2011, 03:31:54 pm
Hi Jan
Thanks for posting the pictures of how the bow is formed - I didn't know that and it was a nice little lesson for me :-))
Dave

You're welcome.

I dindn't want to go the balsa block route and this worked out rather nice, al be it time consuming, as every strip has to be angled correctly to get a nice curve without slits and holes.
Using quick setting glue, it still worked rather quick though.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 08, 2011, 04:26:39 pm
In addition to that, I wanted to build as light as possible as a result od the weight 'trauma' of the polyester test hull..

This 75 cm hull weighs 812 grammes, without the shaft in the picture, the 110 cm version weighed 800 grammes bare wood, with the glasscloth and epoxy it's just over 1000 grammes, so I have a lot more room to play with the goodies inside and still get the riding attitude right.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 11, 2011, 03:23:43 pm
Not much done the past few days, I scanned the rudder section and 'paintshopped' the depth charge 'clutter' away to get a clean view of the rudder assembly:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89949-roer-01.jpg)

Based on the experience with the smaller 75 cm version, I enlarged the rudder surface, to avoid having no steering at all when on the plane.
The blade is 0,8 mm brass, the shaft Ø 4mm spring steel, unfortunately my Dremel cutting disks were thicker, so the slot in the shaft had to be sawed manually, which, due to the nature of the spring steel, took some time...

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89940-blade-shaft-01.jpg)

 (http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89941-blade-shaft-02.jpg)

As brass soaks up a lot of heat, I used a paintstripper to help heat up the material, while soldering the joint with my 100W iron.
It must have been a peculiar sight, me soldering away, with the paintstripper clutched between my knees...

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89943-joined.jpg)

I'm not quite satisfied with the looks, I may heat it up and make some more solder flow properly.

And a little testfit ofcourse:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89945-testfit-02.jpg)

At work, I used the circular saw to cut some aluminum U-profile into a motormount.
It fits niceltly between two bulkheads.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89947-motormount-02.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture89946-motormount-01.jpg)

To get the angle right, I'm going to make a wooden support onto which the motormount will be attached using silicone, to dampen the vibration and noise to the hull.

Regards, Jan.

Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 20, 2011, 08:58:37 pm
Progress is slow, but I've finished the rudder assembly out of brass strip and tubing:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture91049-pivot-01.jpg)

Despite softening the brass strip with the flame, forming the brackets turned out to be a lot of work.
The glare in the pictures fortunately masks some of the toolmarks still visible...

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture91050-pivot-02.jpg)

Still have to make the pin.
After mounting it onto the hull, the motormount and propshaft are next.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: MikeA on December 20, 2011, 09:51:45 pm
what kind of motors are they? the rudder looks good btw
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 21, 2011, 08:51:54 am
Hi Mike,

The motor in question is a fan motor from a french car; I made cooling slots in the housing and added brushtab and cancooling.
For the model in question this amount of added cooling is overkill, but I wanted to see how far I could push a 12V motor without bits melting off...

Tank testing on 24V, with the watercooling running revealed that the motor does barely warm up, during the testrun of 20 minutes full throttle.
In the M.A.S., the Voltage is limited tot 6S due to the limits of the ESC selected, so I expect not thermal issues at all.

Once the propshaft is installed, I can go for some testruns on open water, to check if the tank tests are a good indication for heat buildup (or lack there of) and power consumption.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on June 22, 2013, 10:04:45 pm
It has been a while, but I did manage to get some work done on the M.A.S.

I abandoned the big and heavy brushed set-up for a lighter and smaller brushless outrunner:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture154641-c4250-800kv-01.jpg)

Main reason is the fact that I can get the shallow propshaft angle that wasn't possible with the much larger brushed motor, having a lighter boat is also a benefit for a planing hull:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture154644-hoek-schroefaskoker.jpg)

The motormount is made out of L- and U-shaped aluminium profiles with slots for the mounting bolts to allow the motor to tilt to the correct angle:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture154642-c4250-800kv-02.jpg)

The bolts in the bottom parts are for adjusting the height of the motormount and keeping it there while the polymer kit cures, so the allighment stays intact.
Once the kit has fully cured, the bolts will be removed, leaving the mount on a kit bed to reduce contact noise with the hull.

As you can see the mount is longer than the 800Kv C4250 Aeolian motor, just in case the brushless option doesn't work satisfactory, I have room for a Bühler, which has a longer can:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture154643-c4250-800kv-03.jpg)

Next I have to find an ESC that gives me a better low end respons than the two I've tested with; the Turnigy T-120 makes the motor burst into life at quite a high rpm, making crawling out of the question.
Oddly enough this ESC gives an excellent low end response when going into reverse (but only at 50% max throttle).

So is anyone has a suggestion how to set-up this ESC for scale boating, please let me know.

A 100A EZrun car ESC does the job, but also has a rather coarse low end, only both forward and reverse...
I couldn't find any soft start options in the programming to remedy this, so suggestions anyone?

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on June 26, 2013, 08:19:33 pm
A small update, not mucht time for the hobby during the week.

The strut is in place:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture154938-uithouder.jpg)

To avoid drag, the reinforcement, in the form of two steel pins through the brass strip is inside the hull, glued onto the bottom and covered in glasscloth and epoxy resin.

Also, the stuffing tube has been glassed in.

Pictures will follow once the resin has cured.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 17, 2013, 09:34:58 pm
A long overdue update with pictures.

The strut reinforcment inside the hull:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture155266-uithouder-03.jpg)

The grease tube on the stuffing tube:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture155269-smeerpijpje-02.jpg)

The rudder is operated as the original, with lines and pulleys:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156158-roeraansturing01.jpg)

As there's no deck yet, the pullyes are a temporary fit:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156159-roeraansturing02.jpg)

The servo sits in the position where the wheelhouse is going to be, in front of the motor:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156160-roeraansturing03.jpg)

Top view:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156161-roeraansturing04.jpg)

I grabbed a charged Lipo, mounted a 40 mm prop and went for a testrun.
 The was very little wind, so I took my chance and didn't fit a makeshift deck.
 
 The Ø 40 mm prop was too small, the boat ran nice, but beyond half throttle the prop started to cavitate in the air, drawn under the hull by the steps.
 
 Full throttle resulted in more foam and less speed.
 
 The next size prop (Ø 50 mm) gave a better result, still pretty slow on minimal throttle, with the ICE 150A (forward only), but again a lot of cavitation over half throttle.
 
 The largest prop that fits is a 60 mm, so I gave that a try, even with this large X-prop the low speed was workable, not an absolute crawl, but the real thing didn't idle about much too...
 
 Less than half throttle was enough to get the boat on the plane, looking the part.
 
 Full throttle had a little cavitation, no surprise with the amount of air under the hull, but the large prop kept pushing the boat faster and faster without suffering from the air.
 
 Due to the enlarged rudder, steering kept working at all speeds, although I was reluctant to steer when the boat raced by at full speed, a guesstimate would be over 50 km/h, rediculously fast, virtually no hull in the water, riding on the steps and the prop the boat looked awsome.
 
 Turning at full throttle wasn't an option, as there wasn't enough room in the canal as the boat already began to slide in turns at half throttle, quite fun to do, but also scary; if the side would dig in, the boat would turn over.
 
 On what proved to be the last run of the day, I ran full throttle over something lurking just under the surface, hitting the prop.
 The impact made the rear of the boat jump out of the water, the lipo was ripped loose and went overboard, dragging the ESC and the reciver from their position aswell...
 
 The boat floated some 8 feet from the jetty and I could see the three motorleads sticking out; the ESC leads had been disconnected by the lipo going for a swim.
 
 After retreiving the boat, all electronics were wet, the ESC hung overboard, under water, on the receiver lead, the 4 mm goldies are not designed to hold a Lipo, so the battery is lost at sea...
 
 Without deck and superstructure, the boat is very light for it's size, hence the outrageous performance at only 10.000 rpm.
 I planned on running parallel packs, adding weight and runtime, but unfortunately one of the set, that was going to be in the boat, now lies at the bottom of the canal.
 
 Things are drying, as I type this, the ESC has been waterproofed, so once dry, it should work again, the receiver was moist, it will work again when things have dried out.
 There was some water in the hull after the impact, but the inside is completely covered in epoxy, so no damage to the wood. Surprizingly the strut reinforcement wasn't damaged.
 
 All in all not a bad result, but I was surprised that I needed a huge prop to overcome the cavitaion issue at full throttle.
 This is going to be a fun boat to drive!
 
 Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 17, 2013, 09:36:05 pm
After the minor disaster of loosing a lipo overboard on the maiden run, I made a clear plastic deck, properly fastened the lipo's, ESC and the receiver and went for a walking expedition along the canal.
 
 It was the second day of what could be called summer, so under the plastic, the motor was already 50°C just sitting in the sun.
 
 I ran the boat at a third throttle for most of the time, a brisk walking pace, with the occasional sprint to annoy the local youngsters in their small outboard powered dingies, by outrunning them whenever they wanted to race the old man and his toy boat...
 
 On the way home, about an hour and a half later, sailing downwind (virtually no cooling wind over the hull), the boat stopped dead in the water, no propulsion, just rudder.
 I suspected overheating of the 150A ICE ESC and left the boat to drift downwind untill things had cooled down a little and I could get the boat back to shore.
 
 Both motor and ESC were rather hot to the touch...
 
 I carried the boat for a mile, letting things cool down and tried again for the last leg home, things were sufficiently cooled down and everything worked flawwless again.
 Total runtime over two hours non stop.
 
 At home I recharged 4200mAh back in the batteries (two 4S 4800mAh Lipo's wired in parallel), so, I had juice for more than three hours of runtime mostly cruising with a dozen or so speed events.
 
 Next is looking into getting both motor and ESC watercooled, not simple on a stepped hull, the options are just in front of the first step, or behind the prop.
 
 Behind the prop would mean a pipe sticking out of the hull.
 In view of the amount of rubbish, collected today by the prop and rudder, I don't think I'll go that route.
 
 Unfortunately the motormount is slightly in the way of an intake in the step.
 
 I'll have to give that some thought, as both intake and outlet have to sit close to the center of the hull to be in the water when the boat is on the plane, having a pressureless sytem as on my Arowana's, when running at low speed and still have flow.
 
 Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 17, 2013, 09:42:40 pm
Last week I fitted some Ø4 mm aluminium tubing in the hull as inlet and outlet for the watercooling":
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156598-waterkoeling-02.jpg)

The inlet is slanted forward, the outlet rearward, the idea is to have a pressureless system where the sucktion of the outlet keeps the flow going even when the boat is at crawling speed:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156600-waterkoeling-04.jpg)

The motormount got an aluminum cooling block with one hole drilled through the top, there's room for a second hole, but I'll give this a try first.
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156599-waterkoeling-03.jpg)

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 17, 2013, 09:43:46 pm
Last saturday I did a tour around our city, about an hour and a half of walking pace with short sprints.
 
 This time I had remembered to take the temperature mesuring thingy with me, so I could monitor if the cooling worked.
 
 There was no sunshine during the run, so the warming up wouldn't be from the radiation.
 Both motor ans ESC didn't exceed 45°C, so on an overcast day, I wont have overheating issues.
 The pressureless cooling loop performed as I expected, once filled with a short burst of throttle, the flow kept going, even when I was creeping along.
 
 I did experience an annoying series of five beeps from the ESC, but according to the manual that was the receiver complaining about not receiving a sufficiently strong signal, nifty...
 Time to change the batteries in the transmitter.
 
 Now for a complete deck, as this hull runs very wet, covering the first half reduced the splashing from running through waves, but the exposed rear half needed emptying several times during the journey.
 Good thing there was nothing to get wet, as everything was covered by the half deck.
 
 Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 17, 2013, 09:51:34 pm
Running pics!

As my son now lives on a canal, a photoshoot was in order.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156761-bonke-01.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156762-bonke-02.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156763-bonke-03.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156764-bonke-04.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156765-bonke-05.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156766-bonke-06.jpg)

 I'm not (yet) used to running such a large model and made the mistake to slowly run over the wake of a passing boat, catastrofy was eminent:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156767-bonke-07.jpg)

The hull dropped down the wave and pierced the next one, causing a massive swamping over the partial deck:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture156768-bonke-08.jpg)

 The boat nearly sank, but she finally drifted within retreiving distance.
 All goodies have been dried thouroughly and everything works again, fortunately the ESC is waterproofed.
 
 Next: a closed deck!
The first formers are glued in place.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 26, 2013, 08:58:00 pm
As it was quite hot here last week, other than another testrun with a closed deck, I didn't do much more work on the boat, too hot.

During the testruns the bow wave crawled up towards the deck in fast turns, so sprayrails were in order.
Fortunately the plan shows where to put them, so I boiled some strips to make them soft enough to follow the tight curve of the bow and let them dry overnight.

Next, the position was marked, the skin was sanded, degreased and the port strip was clamped in place and tacked on with cyano:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture157741-sprayrail-01.jpg)

I secured the strip with wooden dowels (Ø2 mm cocktail pins), tapped with white glue into holes drilled through the sprayrail and the skin into the bulkhead underneath:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture157742-sprayrail-02.jpg)

Once the glue has set, the pins will be sanded flush and the rails given a coat of epoxy (and maybe some glasscloth).

First the starboard rail tomorrow.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Big Ada on July 27, 2013, 06:27:19 pm
Looking Good Jan.
What sort of Kites do you fly, looks like single liners with a line reel like yours.
Len, also a Kite Flyer.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 27, 2013, 07:41:18 pm
Hi Len,

Yes single liners, I like the big reels, which allow me to reel in long lines fast enough when the wind decides to turn, or stop blowing altogether, just when I've managed to reel out 400 m.

The speed with which I can reel in makes the difference between losing a kite at see, or in a forest, or keeping it airborn long enough to get it back.

But who am I telling this...?

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: raflaunches on July 27, 2013, 08:00:52 pm
Hi Jan


You are doing a fantastic job, I was tempted to build a MAS boat several years back but my Dad's CMB won the deciding vote between him and me! I've had to buy the Italeri kit instead. Looks like you'll have fun with the torpedo mechanisms when you start on them if the Italeri kit is anything to go by!
She looks good on the water, at least she didn't sink on test trials.
Best regards


Nick B
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Arrow5 on July 27, 2013, 08:32:56 pm
400 metres ?   Can you see the kite at that altitude ?   Nice sailing area you have.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 27, 2013, 09:19:16 pm
Hi Arrow,

Only if the kite is large enough...

On other occasions I get weird looks from people who see me stare at a line disappearing in the sky without something visible at the end, if the kite is smaller.

It's a real kick when the kite travels up through different layers in the air where the air moves in different directions, creating an sharp bend in the kiteline...

@Nick B: I've studied the pictures of the Italieri build and I must say I have a better understanding of the way the deck details should look, my plan is somewhat simple and doesn't show much detail.
I know there are much more detailed plans available in Italy, both of the real boat and RC versions, but as mine will be a running model, I'm not going overboard on details, they tend not to survive frequent outings on the water.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Arrow5 on July 27, 2013, 10:28:45 pm
Thanks Jan,  lots of height restrictions in the UK for model aircraft 400ft. half that for kites.  For UK ( OK Scots) the Forth Rail Bridge is 400ft or thereabouts.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 27, 2013, 11:10:40 pm
Hi Arrow5,

Officially we have height restrictions too (100m), but I haven't been caught (yet).
It's mainly a matter of only letting out so much line in places where you won't get in trouble so quick.

Near an airport I'm (kite)flying very low I can tell you...

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Big Ada on July 28, 2013, 06:08:16 pm
Hi Jan,
I have not worked out where you are based, could you put your location in your Profile = Country / County.
I am a member of The Kent Kite Flyers, Google to have a look at our Web Site.
 
Regards,
 
Len ( I am rokbotton on their web site.).
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on July 30, 2013, 01:57:34 pm
Small update,
Both sprayrails are monted and covered in two layers of epoxy:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture158138-sprayrail-03.jpg)

The testrun showed they work like a charm, deflecting the spray to the side, instead of the bowwave crawling up to the deck.

This boat is such fun to run, both slow and fast!
It shows similar charactaristics as the 1:1 versions; it runs prefectly om smooth and light ripples, but it doesn't like waves at all, she dives in and gets stopped dead in her tracks when I try to run over too large wave(lets).

You have to keep your eyes on it all the time, as the flat bottom design is also very susceptible to wind.

Regards, Jan.
Title: Movie!
Post by: pompebled on August 21, 2013, 04:52:34 pm
I took the unfinished hull with me on our vacation on the river Weser, my nephew made the movie, turn up the volume to hear the boat noises, as he has muted most of the sound:

http://www.youtube.com/watch?v=-igDcvLySEM&feature=youtu.be

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on November 18, 2013, 08:11:06 pm
Last week the MAS stopped in the middle of the canal; the motor still turned, but the propulsion was gone.

My first thought was that I lost the prop, but it turned out to be a broken coupler:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture165479-koppeling-02.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture165478-koppeling-01.jpg)

I must have hit something heavy enough to break the ears clean off one half of the coupler.

Fortunately I have a few spare parts, so the damage was quickly repaired, but I added a piece of silicon tubing to prevent the loss of drive, should the plastic parts break again in future.

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture165480-koppeling-03.jpg)

Not even Raboesch parts hold up indefinitely under the 'torment' of 10.000 rpm on a 60 mm prop...

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Martin (Admin) on November 24, 2013, 09:58:40 pm
Missing photo #16 fixed.   :-)
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on November 25, 2013, 08:45:33 am
Thanks Martin!

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Norseman on December 06, 2013, 07:27:40 pm
How is the build going Jan?

Dave
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on December 06, 2013, 10:08:34 pm
Hi Dave,

 Work on the MAS is very slow, getting the double curvature of the deck and having a large enough access hatch needs some contemplation, next to that, the celebration of Sinterklaas is approaching rapidly and I'm doing some repair work for a Dutch fellow boater on his Apparition cat, so my spare time is well filled at the moment.

The formers for the front part of the deck are in place, so I'll experiment with 6 mm Depron sheet, to see if that will follow the curvature without buckling.
The idea is to fit a false deck out of Depron sheet which I'll cover with glasscloth and epoxy.
Once that has completely cured, I remove the Depron and glue the epoxy deck onto the formers.
The plan is to have the support for the hatch built in, so when the deck is glued on, it's a matter of cutting along that outline to get a well fitting hatch.

Once I've got it all worked out in my mind, I'll get cracking on with the build.

 Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: Norseman on December 06, 2013, 10:14:17 pm
needs some contemplation
:-)) A quiet shed and an open bottle, repeat as often as necessary  O0

Dave
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on March 06, 2014, 10:31:54 pm
Another small update.
 
 Cold water and a plastic prop works fine, as long as you don't encounter a half submerged branch and accidentally run over it...
 
 A while ago I lost one blade of the red Graupner X-60 prop, by just doing that.
 Right, the boat doesn't run too bad with just one blade, albeit a bit noisier due to the vibrations and less speed, but revving slow, I didn't notice too much difference.
 
 A boating buddy pointed me towards a German manufacturer of aluminum CNC props, so I ordered a few:
 http://www.rc-prop.de/index.php?page...chk=1&Itemid=1 (http://www.rc-prop.de/index.php?page=shop.browse&category_id=1&option=com_virtuemart&Itemid=1&vmcchk=1&Itemid=1)
 
 The props look good and can be used without balancing them, here the 'single blade'  red prop next to the CNC props:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture178790-de-rode-x-60-naast-de-cnc-props.jpg)

The 5875 prop on the shaft, with the 5775 next to it:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-motoscafo-anti-sommergibile-picture178791-op-de-de-5875-ernaast-de-5775.jpg)


 The weather has been quite nasty the last weeks, so I only got around to testing them last weekend; the boat runs as it did before, maybe even a bit quicker, as the CNC prop doesn't flex.
 I haven't measured it (yet), but I suspect the Ampdraw is a bit higher too.

Regards Jan.
 
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: derekwarner on March 06, 2014, 10:48:09 pm
mmmmm those CNC props look very sharp  :-))...& another beauty of CNC is that the costing's are not excessive
 
Jan....the coding's...."5875 prop on the shaft, with the 5775 next to it"...... is the diameter x pitch? ..........it's just that 57 & 58 sound funny numbers for diameters

Derek
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on March 07, 2014, 08:47:40 am
Hi Derek,

The first two is indeed the diameter, the last two the pitch.
Henrik Woldt makes a lot of these 'odd' sizes, check out the site.

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on May 02, 2014, 07:57:11 pm
No building progress, just a small video with my newly aquired Mobius camera:
 http://youtu.be/JTYDvmR4p8U (http://youtu.be/JTYDvmR4p8U)

This close to the water, the speed looks frightning to me (and I'm driving it...).

Regards, Jan.
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: gra2 on May 03, 2014, 07:44:51 am
Hi Jan looks good.

Graham
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: gwa84the2nd on May 06, 2014, 12:46:55 am
looking good there bud she performed very well do you have a link to the camera set up your using very interesting
Title: Re: Motoscafo Anti Sommergibile, a lengthy build...
Post by: pompebled on May 06, 2014, 05:36:19 pm
The camera is the Mobius action camera, I got mine here:
http://www.banggood.com/Mobius-Full-HD-Sports-Camera-1080P-30FPS-720P-60FPS-For-Multirotor-p-90648.html?utm_source=google&utm_medium=cpc&utm_content=nydia&utm_campaign=Src-nr-mobius&gclid=CJrQmIrcl74CFbShtAodl1IAIw

The mounting clip that comes with the camera is screwed onto a plate on a sailwinch, the winch is limited to 360°, so I have some idea where the camera is pointing at, when I turn it remotely:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-mobius-op-zeilservo-picture188869-camera-op-servo-01.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-mobius-op-zeilservo-picture188870-cos-02.jpg)

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-mobius-op-zeilservo-picture188871-cos-03.jpg)

For the recording, the servo was mounted on a piece of foam (just visible in the first frames left lower corner) taped to the (not yet finished) hull.

Regards, Jan.