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

[JHapprich]

Did you spray the mixed filler with the compressor? What brand did you use!

Nice and clean work!

[He Who Shall Not Be Named]

So! Lex Luthor is one of us. (squeal of joy!).

[DrSchmidt]

Time for some 2K epoxy filler....nasty but good. Went well. When the filler is cured it's 600 grid wet sanding and then'we'll see. I guess I'll need some more bondo here and there, but as the master determines how good the grp hulls will be, it's worth the effort.

[DrSchmidt]

Lots of progress...well, invisible one, as filling and grinding doesn't change the shape of the boat much, bit it will be visible, when the filler is applied. And that's what 's going to happen next. To be able to apply the filler/primer, I have to suspend the boat somehow. as there is no obvious attachment pint, I had to create it myself. So I glued two M4 threaded insets into the keel and made a suspension frame with a counter weight. Now the boat hangs straight and freely accessible under the ceiling of the work shop. Next I will degrease it once more with "Silikonentferner" (I guess something like the soft solvent David uses). And then it's going to be 2K epoxy filler/primer.

[DrSchmidt]

I have filled and sanded all the seams and obvious geometric flaws. Looks not like much, given the hours of sanding that went into the master so far. But it feels very different by touch and one can see form the putty areas, that there were quite a few uneven regions that are now straight. Next I'll glue some threaded insets into the keel to get attachment points for painting and mounting and the we are ready for the first round of 2K filler....

[DrSchmidt]

Wet sanding the seam....I really hate it. But I make progress.

[DrSchmidt]

A little progress....master building galore: I filled the seams between the 3D-printed segments using polyester putty and now it's grinding, grinding, grinding....

[DrSchmidt]

In a first step I glued all the segments onto the 25 mm x 25 mm steel tube suing epoxy resin. The seams between the segments were filled with epoxy resin that was transformed into a putty using micro balloons. Resin mixed with micro balloons can fill large gaps without cracking, is easy to sand, and gives a good foundation for the polyester putty that will be applied next.

[JHapprich]

What garage?!

wintertime sees attic-action!

[Davidh]

Yes U -23 runs nicely. I thought it would porpoise with the boat hull shape, but it doesn’t. It looks awesome on the water.

Joerg, Thankyou for the compliment. I’m glad it isn’t in your Garage!

[JHapprich]

Its probably the best kit David produced so far. Shame shame mine is still resting on the attic, taped together and awaiting construction

[DrSchmidt]

Yeah, I like your U-24. Is it a good runner? I like these early Imperial German boats, but the arrangement of the control surfaces (all on the bow side of the propellers, not after them, in the prop stream) usually makes them a bit hard to turn and pitch control is tough.

[Davidh]

Andreas,

I will be looking forward to seeing how this goes. Loved your U-1. It helped inspire my U -23 build, a boat that is a lot of fun the drive.




David H.

[DrSchmidt]

There is an awesome cutaway model in the Deutsche Museum where the U-1 is located today....

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

Cheers Andreas

[DrSchmidt]

The compete hull is a new designe and much more accurate than the first version. The bow is new and has the right cross sections, the stern has the right cross sections, the deck is curved the radii on the transition from deck structure to lower hull are right. The general look ist the same, but it's a completely new hull.

And no idea about the wtc yet. The boat can fit 2" tube. That's all what I care about right now. Making a good master in a technique that I haven't employed before is the main thing right now.