atic: 1:35 Bronco XXIII with interior

[goshawk823]

That’s an awesome piece of work for that assembly.

[DrSchmidt]

Put some work into the conning tower. I'm very happy how the hatch turned out. The springs, mechanics and seal, all there like in the CAD model. Looks very good...









The roof of the preesure hull of the conning tower got the rollers and tightening mechanism of the cable pulley for raising and lowering the periscope. Also the light is in place.



The conning tower itself got its switches, sockets and boxes. The cabeling was done with 0,2 mm diameter soldering wire.



Allot of thought went into the alignment of pressure hull, the hull of the kit, the conning tower and the sail of the kit. I decided to use the periscope as the centering point. The periscope shaft of the pressure hull was aligned with the respective hole in the hull of the kit. The periscope shaft of the pressure hull got a 3 mm diameter center hole. In inserted a removable plug into the periscope shaft of the conning tower. This plug has a 3 mm pin that slots into the shaft of the pressure hull. This the kit, the pressure hull and the conning tower are aligned. The top of the plug in the conning tower has a 2 mm diameter center hole in which I inserted a 2 mm rod that I used to align the roof of the conning tower to its floor. Onto the 2 mm rod I plugged a 5 mm diameter steel tube (the periscope) that I then used to align the sail of the kit. This way, everything is perfectly aligned. In a first step I then glued the pressure hull of the conning tower to the hull of the kit. In the second step I taped the halves of the sail together and glued the starboard half to the hull. After the glue had set I removed the port side of the sail and happy me....everything is in the right place and easily accessible for the installation of the masts.

[rwtdiver]

Hi Andreas,

Are you using mostly water base acrylics for your detail work?

Rob
"Firemen can stand the heat."

[DrSchmidt]

Yes, I exclusively use Vallejo colors (Model Air), Pigments and Washes. For filters I used to use oil-based products, but switched to thinned-down washes instead. The only oil based product I still use is light and heavy rust by AMMO MIG.

[DrSchmidt]

Again a little update about the sail....allot of work has to be done integrating parts that were designed using original plans, into the sail parts of a plastic kit. So allot of measuring an adjusting had to be done. Here's the first test fitting of the masts (incoming air, outgoing air and the snorkel masts). The intermediate deck in the aft section of the sail behind the conning tower is at the wrong height in the kit, and it looks not right. So I scanned the contour of the deck and designed and printed a new and better looking one. Slowly it looks like this could work...

[DrSchmidt]

I made some progress with the interior of the sail...the masts are in place. From left to right: exhaust air mast, air intake mast, snorkel exhaust air mast and snorkel air intake mast. Hidden behind the back, of the snorkel intake is the direction finder mast. The diagonal tube in front of the masts is the vent line for the center ballast tanks with the vent valve. The brass rod in the back is the drive shaft of the gearbox that raises the snorkel. The front brass rods are the drive shafts of the valve connecting the snorkel intake to the intake mast. The two vertical tubes that reach to the intermediate deck in the sail are the fuel oil line and the respective vent line. Behind the masts is the exhaust muffler....yet to be placed.

[DrSchmidt]

More progress: All the mast are now in place, including the head valves of the air intake and exhaust on the upper deck. I also installed the Diesel head valve, the muffler and the exhaust....in front of the conning tower the klaxon has found its place. The klaxon had been installed diagonally which necessitated a quite demanding form of the horn. I guess they knew what they were doing. But the thing that makes me the happiest is a package that arrived from the USA, sent by the one himself! The prop of the kit is a crude piece of plastic and I'm very happy that I'll be able to replace it with a cast one made by Mr. Merriman himself. No compromises on this build.

[MFR1964]

Outstanding work Herr Doctor, as you allready probably know, keep the prop steel like the original one.

Manfred.

[DrSchmidt]

Thanks for the reminder....I read about the steel prop but most probably I would have forgotten about it when the time of installation comes.

[DrSchmidt]

On with the conning tower...I installed the hatch to the control room and the ladder to the bridge. Quite crammed in that barrel...also the hatch to the bridge is in place. With the starboard side of the sail secured with scotch tape it already looks like something.

[DrSchmidt]

The CAD model and the print of the snorkel head are ready as well. This is about the limit what my printer is able to pull off...the gratings have 0,3 mm diameter. The head was printed in 4 pieces and glued together....





The ocular box of the periscope and the respective pull-down wire have also found their place. The periscope is a quite complicated affair. On top the shaft seal with the deflection pulleys for the raising and lowering of the periscope. Below the compass rose with the circular light, The picture of the rose is picked up by a prism on the backside of the ocular box and projected into the field of vision of the operator. Blow that is the pulley ring that is attached to the wires of the pulley mechanism. Finally the ocular box....

[DrSchmidt]

What kept me occupied over the last week was the openings for snorkel and direction finder antennae in the roof of the sail. Position, size, shape and orientation are all slightly wrong in the kit. So I designed the correct openings in the CAD and in a first step printed a mask, that I could position on the roof of the sail quite exactly using the masts of the snorkel (6 & 5 mm steel tubes). I copied the contour and adjusted the openings to match the contour. Then I printed a frame with the correct shape and orientation of the openings ad glued it into the adjusted hole from below (won't be visible later on). Filled the gap with putty, filed everything flush with the top side of the roof, et voila....

[redboat219]

The CAD model and the print of the snorkel head are ready as well. This is about the limit what my printer is able to pull off...the gratings have 0,3 mm diameter. The head was printed in 4 pieces and glued together....

Would it be possible to 3D print a working scale snorkel head valve for use in a snort system?

[DrSchmidt]

I don't thik so....moving snorkel ball yes, that'd be pssible, but functional in a ballast system...no. The buoyancywould be too small

[DrSchmidt]

I went on with the rod antennas, that I haven't seen recreated correctly on a model. The antennas were manually raised and lowered. For that there were guide rods left and right of the conning tower that reached from the bridge through the bridge deck down into the sail. The antennas had bases that glided on the the guide rods and that contained the connections to the antenna cables. The antennas themselves were clad in rubber to provide better grip for manually hauling them up and down. Once raised, the were secured using simple turnbuckles. I made tha antennas from 0,3 mm diameter spring steel over which I put pieces of thin-walled brass tubes of 0,8 mm, 1 mm, and 1,2 mm diameter. Antenna bases, turnbuckles, and the supports for the guide rods were 3d-printed. The antenna cables were made using 0,8 m diameter wire. I displayed one antenna retracted and one raised. The top of the antennas were guided through welded steel supports. I made those of PE parts by rcsubs and 3d-printed insets. After that I glued the starboard halve of the sail to the assembly, added the support for the UZO and the speaking tube, that protruded from the roof of the conning tower. Now filling & sanding....