Akula 1/144 Scratch built

[bwi 971]

As I have decided to make an earlier type AKULA, which carried a circular cross section scoop, had to remake them.
Pictures below show the process of creating the new scoops.

The old shark fin and the new with circular cross section



Scoop Root adapted to hull shape



The inlet was opened up with a handheld grinder.



Grating test fitted (to small on next two pictures)



All seems smoothed out with filler (grey on top of scoop)



Finished scoops, painted and with new grating

[bwi 971]

Previous I made “in-between” masters of the rudders, diving planes so I could cut out the surfaces without any risk, if it went wrong I could cast other ones.

At that time I made separate tools for each part.

For some parts I only crafted one piece although I need two pieces. Of those items I need to cast an additional piece, this time I wanted to try multi part casting.

Pre development I AGAIN had a look at the pictures and explanation from David.

My preference goes to making reusable box for the tooling, this works best for me and it’s supports the silicone very well so I can keep it’s thickness to a minimum (it’s expensive stuff).

I made a tool to create the alinement wholes with ease. This was also a good test to work with cores so this was again a very nice learning process.

Picture below show the process from the creation of the tooling till the actual casting result. Parts involved:

• Aft dive plane
• Fwd dive plane
• Shark fin scoop (not going to use it, but it ad’s quantity)

Grtz,
Bart

[He Who Shall Not Be Named]

Just read the article……Damn you David…..stop ****ing with my self-esteem it’s acting like a AC Waveform.
Grtz,
Bart

I declare truce! We're killing each other!@!!!

[bwi 971]

I decided not to scribe the air intakes in the sail they are too small to get the necessary detail into it.



So I decided to make them.

Could I squeeze 92 holes divided over 4 columns and 25 rows in a 11 x 6.5 x 2mm (0.43 x 0.26 x 0.079”) piece of acrylic sheet……NO I COULDN’T……I calculated that I only could squeeze in 88.
Distance between the holes is 0.25mm (0.01”).




And NOOOOO…… that’s not 3D printed.

Mile 1mm sheet of acrilic down to 0.5mm, mile it into shape (1mm mile).......do not try to shorten your index finger in the process.....you need it for sanding.




Wet sand them to get them all the same thickness…….you have two index fingers if one starts bleeding use the other one......see above miling process




pile them up



Squeeze them togeter and CA glue them......make shure that the CA isn't getting into the slots.



You need 22 pieces and one endplate and your done.

1 done 1 to go

Grtz,
Bart

[bwi 971]

Here's an in-depth article I did on the SEAVIEW assembly:

http://culttvman.com/main/david-merrimans-building-the-57-seaview-introduction/

Just read the article……Damn you David…..stop ****ing with my self-esteem it’s acting like a AC Waveform.
Grtz,
Bart

[He Who Shall Not Be Named]

Still looking at your pictures David.....drooling all over the keyboard…. that’s wonderful stuff sir.

That FOXTROT is tempting for a next project, there is one on display 100 km (80mi) from where I live.

Grtz,
Bart

Just saw your post above.....YOU'RE WELCOME.

Here's an in-depth article I did on the SEAVIEW assembly:

http://culttvman.com/main/david-merrimans-building-the-57-seaview-introduction/

[bwi 971]

Still looking at your pictures David.....drooling all over the keyboard…. that’s wonderful stuff sir.

That FOXTROT is tempting for a next project, there is one on display 100 km (80mi) from where I live.

Grtz,
Bart


Just saw your post above.....YOU'RE WELCOME.

[He Who Shall Not Be Named]

What else can I say then THANK YOU SIR......now I know how to cast those SOKS and other stuff.
One source of a headache less now. (I still hate you though).

Grtz,
Bart

Just when I assumed king-of-the-hill status with my magnificent presentation, you kick me to the curb with that practical hinged bail. *******!

M

[bwi 971]

About the challenge of the hinge slot and flood sleeves:

Challenge 1: Make a hinge with a slot

COMPLETED

Dimendions of the hinge 5.5 x 0.75 x 1mm (0.22” x 0.03” x 0.04”) slot 0.25mm (0.01”) wide.




Tree pieces of 0.25 (0.01”) thick brass sheet , cut, file and sand into shape, one is shorter than the other two, pile them up the shortest one in the middle, glue everything together.











Challenge 2: make floot sleeves in main body

Still in progress


Grtz,
Bart

[bwi 971]

What else can I say then THANK YOU SIR......now I know how to cast those SOKS and other stuff.
One source of a headache less now. (I still hate you though).

Grtz,
Bart

[He Who Shall Not Be Named]

I needed a bunch of ladder-rungs for a spiral staircase. These were best cast using the vacuum assisted method.



Vacuum assisted resin casting made these girder parts possible with the least amount of hassle and clean-up chores post de-molding.



Making the 1/72 figure masters for the defunct FOXTROT project



To the right I'm working up another vacuum assisted tool, this one for 1/72 figure blanks.The figure masters embeded in the backing clay along with the block that will give form to the tools resin trough.

To the right is a gravity-pour metal casting tool set of masters under their tall sprue. In metal casting you need at least a five-inch tall sprue to provide the pressure-head needed to insure a complete fill of the tools cavities.



Cast resin 1/72 crew figure blanks posed upon and around the 1/72 FOXTROT sail components.

[He Who Shall Not Be Named]

About the maniac thing.....my missis says your right 100%



Ok challenge accepted sir.....will revert to you soon.....by the way I hate you.

I know everybody is breathing I your neck David but when you have a moment to spare can you please explain the vacuum casting technique.

My vacuum storage tank is ready to go as you told me pa….and I think I’m gonna need it to cast the small parts?

Grtz,
Bart

Bart wants the dope on an aspect of casting. Specifically, vacuum assisted casting. Vacuum castin simply removes air from the tools cavities, either by voiding air through the pourouse ceramic tool (high-temperature work, usually silver or gold), or frothing the resin momentarily as the applied vacuum extracts cavity air through the resin filled sprue trough. Explained later.

Resin or metal casting, the name of the game is getting a liquide (of usually thicker-than-water consistancy) to completely fill the voids (cavities) of a mold (tool), doing so before the liquid changes state, through freezing or heat induced polymerization of the liquids molecules. The beauty of vacuum casting is that no vent, risers, or gates -- other than the sprue communicating the liquid metal or resin to the tool cavities -- are involved. This results in a cast part free of vent, gate and riser nubs that have to be ground back and finished.

But, the big advantage is that the most complex of cavity geometries will be filled completey without bubbles being entrapped during the state change, ruining the finish of the part.



The typical vacuum assisted resin tool is made much the same way and uses the same rubber as used for normal resin gravity or pressure casting. The difference is that the vacuum assisted tools sprue is a simple long, deep, narrow, open faced trough communicating with the cavities under it through short, narrow auxiliary sprues. No vent channels.

The above very complicated and small masters were used to make of the several vacuum assisted resin casting tools used to produce parts for the 1/96 structures and figures of the Teskey SEAVIEW observation compartment.

(Note the little SEAVIEW 'model' master -- it's one-inch long, sports-fans. Yeah ... I hate you too, Bart!)



This is what your typical vacuum assisted rubber tool looks like. Note that the only sprues are at the feet and hands of the figure parts, leading to the big trough sprue piece. Had I gone with gravity these things would never, in practice, have been complete shots. And even if I went with pressure casting I would have been obligated to provide an extensive vent and header system to vent the displacing air, even then I would have had some short shots -- a waste of time and money.

Note that the hardened resin from the trough produces a big-ass foundation upon which all the cast parts stand. Nice thing about that is it gives you a handle that makes flash trimming, de-greasing, priming and painting a less frustrating task -- easy to hold parts. Like the figure masters above: each a blanks that became SEAVIEW crew masters with some alteration with knife and putty.



You need at least 28.5 inches of Mercury pulled by your vacuum pump ... that's outer space thin, boys and girls. The best set up is a volume tank that is evacuated before you mix your resin. You mix up the resin; pour it in the tool, half-way filling the trough; place the tool on the vacuum table, slip the bell-jar over the tool; and slam the vacuum to it. In the absence of air over the trough, the air under it -- within the tool cavities -- rushes up and through the resin filled trough, breaking the liquid resins surface as frothing bubbles which pop and the air drawn out and into the pump or volume tank. As the air leaves the tool cavities, its displaced by the resin. You vent air back into the machine and wait for the resin to cure hard enough to de-mold, and you're done. Slicker than snot!

See all that nasty resin coating the inside of the bell-jar? Guess how that happened? Some idiot did not make the trough deep enough on one of his earlier vacuum assisted tools. Every watch Outland? No flying eye-balls, but plenty of resin went its own way on that one! I learn the hard way. You don't have to!



If you want to reinforce the resin parts with fiber or the like, vacuum assisted casting permits a complete saturation of the weave, such as these carbon reinforced hatch horns. Note that this one sprue contains all the parts (less escape buoy bail) needed to produce a very nicely detailed submarine deck hatch. The masters used to produce the tool cavities were fabricated from brass, Renshape, and soft wire thread.



1/96 observation compartment small resin parts were almost exclusively fabricated employing the vacuum assisted resin casting process. Small items of complicated form are best done this way as any other method (other than centrifugal casting) will likely produce parts pock-marked with bubble-voids.



To the left are resin parts fabricated using a typical gravity pour, pressure assisted process -- the need and use of vent channels demonstrated here. To the right are four sprues with many small and deeply detailed parts -- no vent channeling or other artifacts of the other casting process here, just the big trough, and auxiliary sprues, and that's that.





Two vacuum assisted tools under construction. The masters are half masked in modeling clay. Yeah, I even made masters of a typical holiday dinner service, right down to the gravy-boat (must have been out of my frig'n mind!). Note the Renshape block used to give form to the eventual sprue trough.

[He Who Shall Not Be Named]

About the maniac thing.....my missis says your right 100%



Ok challenge accepted sir.....will revert to you soon.....by the way I hate you.

I know everybody is breathing I your neck David but when you have a moment to spare can you please explain the vacuum casting technique.

My vacuum storage tank is ready to go as you told me pa….and I think I’m gonna need it to cast the small parts?

Grtz,
Bart

NO! ... I hate you first!

M

(I'm working up a piece on vacuum assisted resin casting as I hate you. Give me a few hours, pal)

[bwi 971]

I see them now and this confirms my earlier assessment.... Bart, you are a MANIAC! God bless you.

About the maniac thing.....my missis says your right 100%

To make those slots: Find or shave a piece of .0039" brass or copper sheet, Cut a strip of it to the length of the hatch fairing cover flood sleeve. Heat it with a candle and press its end into the plastic fairing piece (I assume the plastic is of the thermoplastic type). It will sink in. When cool, pull the metal strip out and with a knife lop off the ridges formed around the strip -- revealing a perfect flood sleeve (slot) of uniform depth and shape.

Damn, I'm good!

M

Ok challenge accepted sir.....will revert to you soon.....by the way I hate you.

I know everybody is breathing I your neck David but when you have a moment to spare can you please explain the vacuum casting technique.

My vacuum storage tank is ready to go as you told me pa….and I think I’m gonna need it to cast the small parts?

Grtz,
Bart

[He Who Shall Not Be Named]

I have been working on the aft escape hatch.

The round body is made out of 2mm (0.078”) acrylic sheet.
The hatch cover is made out 1mm (0.04”) acrylic sheet.
The valve handle is made out of 0.2mm (0.0079”) diameter wire and glued together with CA.
The hinge is made out of 1.5mm ( 0.059”) diameter brass rod made scuare 0.8x0.8mm (0.031x0.031”).

As I don’t have a 0.0039 diameter endmill I was not able to make the small flood sleeves in the hatch nor the slot in the hinge, very frustrating.

Escape hatch of a Typhoon
[ATTACH=CONFIG]n111268[/ATTACH]

Body and hatch cover
[ATTACH=CONFIG]n111269[/ATTACH]

Valve handle
[ATTACH=CONFIG]n111274[/ATTACH]

[ATTACH=CONFIG]n111270[/ATTACH]

All parts ready
[ATTACH=CONFIG]n111275[/ATTACH]

The end result
[ATTACH=CONFIG]n111273[/ATTACH]

[ATTACH=CONFIG]n111272[/ATTACH]

[ATTACH=CONFIG]n111271[/ATTACH]

To make those slots: Find or shave a piece of .0039" brass or copper sheet, Cut a strip of it to the length of the hatch fairing cover flood sleeve. Heat it with a candle and press its end into the plastic fairing piece (I assume the plastic is of the thermoplastic type). It will sink in. When cool, pull the metal strip out and with a knife lop off the ridges formed around the strip -- revealing a perfect flood sleeve (slot) of uniform depth and shape.

Damn, I'm good!

M