S.M. U-1 (a new RC project)

[DrSchmidt]

What I like about 3D printing is the flexibility it provides to make quick adjusrments. I gound out that there were feedthroughs where the propeller shafts left the hull. So I made CAD models of them, printed them, and here they are. Quick and precise.

[DrSchmidt]

I continued with the lower hull and added the propeller shafts and their supports. The supports are 3D-printed. I was clever enough to mark the positions on the masters where the support struts meet the hull and where the shafts run through the hull. So no big marking issues on the glass fiber parts, just drill and glue. Fixed everything with super glue and the cemented the shafts into place using epoxy.

[DrSchmidt]

So it’s time to continue my U1 project. I‘ll make two versions, one for display and a rc one. This is going to be the display one. I started with the upper hull. I opened the deck for the ventilation mast boxes, glued the 3D-printed boxes in from below and the filed the deckopenings to match the boxes. Filling and sanding after that. The limber holes are long horizontal cuts. To support the superstructure after cutting, I glued 12 bulkheads into it. Should be plenty….

[DrSchmidt]

Got a little package with a beautiful WTC and some excellen detail parts made of resin and white metal by the grandmaster David himself. I'm very happy. So after my Type II project I'll have something new to do....

[DrSchmidt]

Got the molds for the lower hull going and Friday I laminated the second piece. Took it out today and turned ot quite good...one more to go.

[DrSchmidt]

Working on the fleet....

[DrSchmidt]

I've made molds and a few sheets of PE....so probably more than one. But I'm not a good producer for others. The little time I have for my hobby is mostly reserved for myself. Producing a kit is probably 20 hours of work.

[redboat219]

Will this be a one-off or will you be making more?

[DrSchmidt]

I have laminated the first deck section of the U1. Went quite well, despite the tight radius here and there. I used 3 layers of 80g/m^2 glass, the middle layer diagonally to give the deck some more resistance against twisting. Looks good and the conning tower fits perfectly. Going through the effort of making the three piece mold for the conning tower was quite worth it.

[DrSchmidt]

While I prepped the mold for the second conning tower, I printed the housings for the air intake masks. Turned out quite good.....optimized for little water displacement.

Then I made the second conning tower. Got me new surface resin and a better color for the resin. So this went better than for the first one. After brushing in the surface resin, I poweder the resin with cotton flakes to provide a good coupling surface for the GRP. And the second tower is quite good. The first one was O.K., the second one is good. Less bulky, a bit lighter, no voids. So the next ones will be made to match this one.

[DrSchmidt]

Working on the acrylic covers to get a nice edge to the hull parts. So far so good....

Meanwhile: I pulled the second part out of the coning tower mold. Worked well. Still a bit on the heavy and thick side of things, but besides that, quite O.K.. I'll make a few more. One will go onto the RC version, one on disply model, and one for someone else....

[DrSchmidt]

Actually I hought a while abut the control planes. The original ones were very thin, and to properly reporduce those in that scale....3D-printing is the ideal approach.

https://www.der-lustige-modellbauer.com/t5991-u-boot-u1-im-deutschen-museum-munchen

[He Who Shall Not Be Named]

That always evident German slavish pursuit of perfection to the most basic of items.

[DrSchmidt]

laminated the second conning tower today. First try wasn't perfect with voids here and there. So it's a second one, this time with thinner, more flexible glass and some more thickened resin in the corners. Worked well, we'll see the result in 36 hours...meanwhile: I printed control planes, hatches, and some accessories....

[DrSchmidt]

I finished the molds for the conning tower and opened them. Went reasonably well, but again, I had little section of surface primer stuck in the mold, that had to be removed with brute force, resulting with partially rough surfaces. Not really happy about it, but I guess the mold will be able to produce good parts. We'll see. On the bright side: The PE sheets have arrived.