Japanese Class A 1/16

[He Who Shall Not Be Named]

Tried several times to get me a decent propellor by using the mold, either the resin is too weak, or the dimensions of the propellor are too small, also tried to reinforce the propellor with a little brass frame inside, no succes yet, those blades just sheer off after some pressure.
David, is there some other stuff i can use for making the props sturdy and still flexible?, i allready made a second copper one with the use of my prop-jigg so i can keep progress in building the torps, takes about three hours to produce a copper prop, so time is not really the issue, and by using the prop-jigg it's the same as the first one.

Manfred.

Years ago I was commissioned by an effects house to build the propeller masters that would be used to make tools for wheels needed for the movie, Crimson Tide. That work pictured below.They were big wheels and I employed carbon fibers to strengthen the individually cast blades. The resulting resin parts were very strong in shear and torque. Just what you need, Manfred, for your practical resin propellers.

Two wheels (different scales for the MONTANA). And one wheel for the bad-guy, 'AKULA' -- you can see a casting of that wheel spinning of stage-left as the AKULA implodes... Neat!).

If you watch the movie you will see the MONTANA screw at one point going ahead and turning clockwise, and in other shots, going ahead turning counter-clockwise. The second-unit was not paying attention to the story-boards, later compelling the post production guys in the Editing office to flop the film when printing for continuities sake. Bad Ju-Ju!




Notice that the AKULA wheel is a counter-clockwise rotating unit, and the American wheel turns in the more traditional clockwise direction.

Here's what you do, Manfred:

Strip carbon fibers from some sheet, their length about equal to the diameter of the propeller, lay them into the blade cavities of one-halve of the two-piece rubber tool -- the fibers running right through the hub. Pack them in there. Then assemble the tool and cast as you would using quick-cure polyurethane. But, you must pressurize the mix before it changes state as the fibers are bubble-grabbers.

David

[MFR1964]

Tried several times to get me a decent propellor by using the mold, either the resin is too weak, or the dimensions of the propellor are too small, also tried to reinforce the propellor with a little brass frame inside, no succes yet, those blades just sheer off after some pressure.
David, is there some other stuff i can use for making the props sturdy and still flexible?, i allready made a second copper one with the use of my prop-jigg so i can keep progress in building the torps, takes about three hours to produce a copper prop, so time is not really the issue, and by using the prop-jigg it's the same as the first one.

Manfred.

[MFR1964]

With the torps i ran into a tiny problem, the props i needed had to be around 20 mm, two times and fourbladed!!!, decided to get a run at this,



First i made this doomsday contraption with simple means, the result is a fourbladed prop with a moderate pitch, and yes, those blades have profile.



Making of the mold, placed some channels on top of the blades



Made the first silicone pour and turned the mold upside down for the second run with silicone.



Today i opened up the mold by splitting her, the propmaster was easely removed, have to clean out some flash, but they are in decent shape for a amateur like me, tomorrow pouring some resin.


Manfred.

[He Who Shall Not Be Named]

OK i will hold them back, yell if you need those parts in the future, another question, how do you store those molds on the long term?, is ther any kind of deterioration which i have to account for?

Manfred.

The only time-critical rubber I used was that ancient Dow Corning #111 -- those tools are crumbling today.

On the other hand, I have thirty-year old tools that are just as serviceable today as they were back when they were made. With those the only aging is caused by the polyurethane casting resins we use these tools to cast parts off. I get about a hundred cycles off of those type tools before the cavity faces start to crack. The metal casting tools (low temperature metal like lead and white-metal) however are as fresh after hundreds of cycles as they were for the first. I exclusively use the BJB brand platinum-cured type room temperature vulcanizing tooling rubbers.

https://bjbenterprises.com/index.php/silicones/platinum-based/

The perfect part-release (and mold-release) agent is Mann 200, in a spray can. Using it will insure quick, clean, easy part ejection and minimal chemical activity between the rubber and casting material.

https://www.amazon.com/Mann-Release-Technologies-Ease-200/dp/B002YEBO1O/ref=sr_1_1?ie=UTF8&qid=1482086435&sr=8-1&keywords=mann+200

Storage is not a big deal -- most of my production tooling (tons of it by now) is stored in the sheds where temperatures range from blistering hot to freezing cold (and recently, under water). The rubber just don't care!

David

[MFR1964]

OK i will hold them back, yell if you need those parts in the future, another question, how do you store those molds on the long term?, is ther any kind of deterioration which i have to account for?

Manfred.

[He Who Shall Not Be Named]

Hold off on sending those parts -- the V80 at this end has been set way back. New Boss, and more work than I can complete in a day (a good thing). I'll let you know, Manfred. And thank you for the kind offer.

Yes, cats be dangerous animals around the shop. You found, by hacking the two halves of the RTV tool apart that you created a perfect keying/indexing system between the two halves through the ragged knife cuts. Of course, poking a sharp knife in there is not good for the masters, but what the hey?

The upper two pieces of this four-piece tool were slit with a knife, to prove the point.




David

[MFR1964]

So, the first pair was born, made a second set, i should have started earlier with making molds, this is fun stuff.



This was the goal, two identical torpedo's, and now i'm able to make even more.



While i was pouring those torpedo parts i took some parts off from the V80.



Making this mold learned me some things, NEVER!! i say NEVER!!! let the cat inside the cave when you make some, end of story was i forgot to add the mold release stuff when pouring the second time silicone rubber, i ended up with a solid block of rubber, had to cut it in half with a scalpel, i can hear David laugh all the way over the ocean.



Despite that setback the result wasn't that bad, next time make a better mold.



David, those are your problem now, send me a mail with your adress, if you dare!!, i'll pack them up and will send them over.

Manfred.

[MFR1964]

As promised some more pics from the cave,



This is the final result of building my two-shooter, still need to adress the firingmechanism, before i could even think about that, there was something else to do.



Took some pine-wood and started up the lathe, ending up with this, since drawings of this torp are rare, i eyeballed it to get it right.



Compared to one of my electric runners, which are scale 1:35. they look big!!! ( do i think live warhead?)



Can wait to see them running out like this in the future.



Before i could start with molding them i gave the masters several layers of paint and sanded them back each time, i wanted to get them a smooth as possible, this pic is the result of some weeks hard work, HURRAH!!!!!, finally my first born casts in resin, despite the fact i don't own that fancy vacuum stuff David and Bart have, they came out well with no airbubbles, used a makeshift vibrationtable to get those pesty airbubbles out.


Manfred.

[MFR1964]

You know when you start scratching, the itch becomes worse Tom, you found it out the hard way, as for sitting back and learn, i'm starting to learn how to make molds and pour some resin, it will be a fun ride into the unknown, the masters are made and the silicone is poured, tomorrow i'm going to pull them out, and yes, it consumes time making posts, the main objective stays, show what you can do and how, so other builders can do the same trick.

[trout]

Manfred,
Maybe it is time to change the term Manfredize to the Manfred Itch, no, that sounds more like a communicable disease. Anyways, wow, I can just sit back and learn from you. Thank you for posting. I know it takes a lot of time to post, I so appreciate those that do!

[MFR1964]

Thanks Mark, yup, once you've got the itch it's hard not to scratch, right now i'm making some silicone molds, i'll post that adventure later on

[greenman407]

Beautiful work as usual Manfred. Glad to hear your still kicking around in the Garage, up to no good.

[MFR1964]

It has been some time, first had to finish up my second type VII, rebuilded the torpedo system and took my own type VII out of commision, took all hardware out of this boat, it will be re-used for the doomed Type XVIIb.
My own type VII is allready sold to another subbuilder, with plans to rebuild her in working order.
Let's pick up the thread where i stopped,





The conningtower itself is finished and ready to be molded, the plans are to do this next spring together with the hull.



This is my second version of the hatch, the first one had a wheel on top, Von made a remark about the wheel, there wasn't suppose to be a wheel, so it was removed, later on i ordered a book about the Ko-Hyoteki, i've got me a slap in the face and had to alter more things.



The third version was born, now with the correst hinge accourding to the pictures inside the book.



Also had to modify the inside, i decided to start from scratch, i'm pleased with the result, added also the hook which kept it open when on the surface.



Not sure if i showed this pic before with the propellors David made for me, a dryfitt to see if the size was allright.



Since the tempartures where dropping overhere i decided to build me some other hardware, those tubes are from windowscreens.



Dryfitting the netcutter and the future torps.



Builded a frame to keep both tubes together, still had to make the rear bulkhead which will hold the entire contraption, to be continued.

Manfred.

[MFR1964]

Nice Bart, i allready have the book about the Ko Hyoteki, but more pics are allways welcome, for now i'm working on both bikes for maintenance, they will be ready at the end of the week for testing, after that i'm going to start up the cave for some work on the hull.

[bwi 971]

Manfred, Von, David,

I thought I spent my some of my almost unlimited free time I have for the moment to dig in deep into the WWW for any information about your project........and guess what.......I .hit the jackpot all below pictures of the n°19.

grtz,
Bart