Building the Zero Bubble Model Design 1/120 Mike SSN

[JHapprich]

Above the indexing lips, 2018. Rather rough.
2020: Aquired a Scheppach belt grinder. Nice tool! tested by trimming the indexing lips. Will add filler to flatten the inner face:



Also made the Indexing lip for the upper hull, sternwards:

[JHapprich]

Time to focus on my favorite: stern tube, propeller and auxillary pods. Initially i wanted to make my own prop from soldered brass, but as i haven`t much hobby time these days, i modified two Raboesch props to work as a tandem pair. Not quite scale, but quicker to produce. So first of all i cut off the hub cone of the inner propeller and enlengthened the M4 thread all the way through. then figured out how much material needed to be removed - and where - to accomplish a press fit between the two units with the necessary angle towards each other`s blades. Marked the spot, installed my milling crosstable into my drillpress and milled a corresponding step contur into the inner props` front and the outer prop`s back. Cut crosswise into the outer`s hub nose and made brass inserts to "Russianise" the look. Fire on the torch ... and done!

[JHapprich]

Next to do was the stern tube installation. First i had to fill the imperfection at the stern cone.



Brought to shape by wet sanding. i then inserted the tube into the right position and used the shaft with nuts and washers and two wooden discs with orientation lines to ensure the centric alignment. Then mounted the hull pointing upwards and let resin flow into the cone. A small rubber ring at the stern end ensured sealing as well as beeing a placeholder for the propeller`s counter-nut.

[JHapprich]

At the moment i am making the two small auxilary pod propellers. they are made from flattened 4mm brass tube filed into shape with a 2mm stainless shaft pushed through the center and a small hub from 3mm tube. they will be installed in the fixed stowed position that can be seen in the latest footage of the Wreck.

[JHapprich]

Soldered, polished and glued in place with epoxi resin:

[JHapprich]

Nice work Jorg,

You don’t need my permission for anything. I am so looking forward to seeing this boat complete, then the Papa and the Delta...

DavidH

Thanks David, but i made several new molds from your product. Of course i asked...

Jörg

[JHapprich]

Hi everyone! I just gave the boat a nice hot soap shower to erase any dust and cleanup the hull after some time (and cutting concrete in the garage was a bad idea,afterall ) just to find several bubbles and uneven spots at the seam line. So i used clear sticky tape to mask the surface and applied fine filler. Wet sanding will follow.

[JHapprich]

2 o'clock in the night. Family asleep.party time!

[RCSubGuy]

A superb example of attention to detail and perseverance working with a challenging initial subject. Loving what I'm seeing here! Keep it up!

Bob

[JHapprich]

Thank you, Bob! Am quite happy with the progress of the MIKE now and really looking forward to fully focussing on the PAPA. Experience i made with the 685 will be very helpful. Initial work on the 661 has already been done: hull halves trimmed to fit, limber holes opened, z-cut, sail assembly. However i did some major changes to the sail.

Jörg

[JHapprich]

Hello everyone! Today i continued filling the hull's inside after sanding the outside yesterday evening, this time my nemesis on the Mike, the indexing lips. Keep in mind after i messed up trimming the hull, i had to rebuild a good portion of the edges, including modelling the indexing lips as one integrated part for stability. As i had to learn working with polyester resin back then, i was not able to perform that operation the way i imagined, so there was still work left to do.gaps, bubbles, imperfection. Invisible from the outside BUT i would know they were there. So today i carefully applied sticky tape to the outer surface of the indexing lips, mixed up resin and then wiped it into the gaps from the inside. Put on the upper hull. Waiting for it to cure and repeated the process for the other side. Next i initially wanted to lay up glass, but as there were only about 3 section on each side to fill up, i decided to use fibre-enhanced filler. After curing and sanding back, i'll lay up light glass if necessary. Also figured the sail would disengage from the hull after the recent hot-water treatment ( that also effectively cured any remaining "soft" spot on the resin surface ) and applied filler as well. What happened: i used 24hr-epoxy to pin-down the sail and added poly-resin spots afterwards. Seems i did more "pinning" than actual permanently glueing. Not to mention DavidH describing what glue to use for the kit in the manual-i now learned it the hard way.

[JHapprich]

Removed the tape today and did some sanding.

[Davidh]

Hi Jorg,


Looking really nice. So looking forward to seeing it finished. I am back from my holiday and I will probably hit the workshop tomorrow. I have to do an update on the ZB’s progress.


Dave H

[JHapprich]

Hi Dave! Hope you had nice holidays. Did some more filling yesterday and am waiting for a new order if spray primer. Looking forward to you ZB update! Enjoy your weekend!
Jörg

[JHapprich]

Lost some hull detail during the build, so its rescribing for now: