Marking out the bow (headache)

[bwi 971]

I have started with my long (I have ordered the plans in 1997 from deep sea designs “Greg Sharpe”) planned scratch building project of an AKULA submarine almost two years ago.
Don't want to be a buttshark and I know it dangerous to admit here but most of the techniques I have used I picked up from David’s cabal reports in the nineties.

I have almost reached the scribing process now which I have postponed for a long time, kept pushing it fwd. But I have to do it sooner or later.

I’m now marking the hull but the only thing that keeps bugging me is how mark out the circular doors at the bow so they will show up as circle in a front view. Seems that I missed that report David can you help me out here?

grtz,
Bart

[He Who Shall Not Be Named]

Sure can ...

... you shameless apple-polisher, you!

That dope is on slides and negatives -- got to scan them to the hard-drive. Hope to have that mark-off tool piece to you tonight or tomorrow.

I've been following your AKULA work -- and it all is outstanding good work. Your methodology, materials selection, and fabrication techniques are well thought out and rational.

Now who's a buttshark!?

(Hey, Ellie! I just learned a new word ... wanna hear it?)

M

[He Who Shall Not Be Named]

I have started with my long (I have ordered the plans in 1997 from deep sea designs “Greg Sharpe”) planned scratch building project of an AKULA submarine almost two years ago.
Don't want to be a buttshark and I know it dangerous to admit here but most of the techniques I have used I picked up from David’s cabal reports in the nineties.

I have almost reached the scribing process now which I have postponed for a long time, kept pushing it fwd. But I have to do it sooner or later.

I’m now marking the hull but the only thing that keeps bugging me is how mark out the circular doors at the bow so they will show up as circle in a front view. Seems that I missed that report David can you help me out here?

grtz,
Bart

OK, I found the slides (no negatives) and have scanned them into Colossus-Guardian, so we're good to go.

The objective here is to describe a means of manufacturing a scribing stencil that will render a proper circular pattern onto a simple or compound curved scribing stencil.

Think two-dimensionally here. Take your AKULA or most other 'modern' Soviet era submarine torpedo tube muzzle doors which, with few exemptions are true circles when viewed from head-on. But, since these doors fall along a compound curve, that gets ever more extreme as you distance it from the centerline, they will ONLY appear circular from dead ahead (projected view) -- any other angle of view and you observe that they are (developed) physically ovoid in shape. How to make a scribing stencil that captures the correct shape to all the muzzle doors across the face of the submarines bow?

The simplest way to make the scribing stencil torpedo tube muzzle door circles is to mark out the maximum height and width of the holes onto the face of the stencil -- some careful lay-out work here as you loft the information off planes, photos, and drawings. Then, its a simple matter to yank the stencil off the bow (it was there as you laid out the boarders of the eventual cut-outs), punch rough holes, then finish them off with a round-file of the correct diameter -- taking care to keep the long axis of the file parallel with the long-axis of the hull (I assume all Ruski boats bore-sight their tubes parallel with the boats longitudinal axis).

That's the cave-man approach. A more accurate method is to mark-off the scribing stencil with a drop-pin/drop-pencil.

Here's how a drop-pencil is used to mark off circles onto simple or compound curves.

And some bonus material for you: the use of vacuformed, GRP laid-up, and other types of scribing stencils used to guide the scratch-awl.

Go get 'em, Tiger!

M

[bwi 971]

I don’t want to turn this into one of your beloved “ 'thanks for sharing', 'nice job', 'LOL' bull-****” posts, so I just go to the basement and start inhaling those polyester resin vapors .
Grtz,
Bart

[He Who Shall Not Be Named]

I don’t want to turn this into one of your beloved “ 'thanks for sharing', 'nice job', 'LOL' bull-****” posts, so I just go to the basement and start inhaling those polyester resin vapors .
Grtz,
Bart

There you go!

Deeds, not words.

M

[bwi 971]

Monkey see, monkey do.....

Grtz,
Bart

[He Who Shall Not Be Named]

Monkey see, monkey do.....

Grtz,
Bart

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Wonderful job, Bart! Wonderful. I mean it, pal ... that's good work.

You know how to fix that elongation that resulted from the thickness of the stencil, don't you?

M

[bwi 971]

Just following your methods sir.

I was actually pondering on it last evening.....no I don't……I’m ready to be tarred-and-feathered…..shoot.

Grtz,
Bart

[bwi 971]

Ok.....made a test piece.

I only needed the shape adjacent with the hull so the Lower plane was filled up with CA glue and soda (radius was supported by wax paper) and the upper plane was enlarged with a needle file until it matched with the lower edge (This stuff is hard to explain in English hope pictures will clarify).

What I also noted is that the stencil has to be perfect to get a good scribing result. Every glitch is transferred when scribing....it even seems to be blown-up as you look at it on the hull…..so the prep is everything……as always.

Back to my basement now.
Grtz,
Bart

[He Who Shall Not Be Named]

Now, this is the sort of WIP I enjoy most, Bart: Excellent photography, brief but concise text, and graphics to enhance the story-telling of the photo. Great stuff, sir.

M