Germany's first military submarine, the S.M. U-1

I'm currently building Germanie's first military submarine, the S.M. U-1 from 1906.



The model is based on the only existing overall plan.



I didgitized it, scaled it, and based on the drwaings I created a 3D CAD model, which is the basis for my model:

Based on the CAD drawing I got begative moulds milled out of hard foam. These negatives I used to build a positive out of glas fiber composites.













After the cutring of the resin, I basically cut and grinded the foam of the positive. Here the lower hull:

Same procedure for the upper hull:







And the result - the still relatively crude positive model:





The mould for the conning-tower I did before based on a positive model I got fabricated via rapid prototyping.

Thanks!

After I got the raw positive, lots of grinding, sanding, filling, and finally painting and polishing got me here:









Then came the nasty part - building the moulds:








70 kgs of them actually...

Three months of work, but they turned out really good:

what a fantastic skill you have keep up the great work

That's "REALLY OW SOME" like he Americans sad.

Is Really Great what You have don.So Much effort but is worth it.
Please keep as on post with your work.

MARIUS

P.S. How many Kilograms of Silicone Rubber did You used?!...60-75KG!!!.

The moulds for the hull weigh about 70 kg. They are made out of resin and glass fiber.

SEE I have a GOOD eye!.

After the moulds were done, I made the first glass fiber parts for the actual boat. The conning tower:




The upper hull with conning-tower:





and the raw assembly:

At that stage I also had the interior design ready:



It's loosely based on the Engel VIIc interior design and works with 2 x 750 ml piston tanks, brushless motors and LiFePo batteries.
The technical components are mounted into a frame made out of 5 mm milled thick glass fiber plates and M5 thread rods:





The whole assembly will be housed in glass fiber tubes sealed with bayonet coupling:

I've also started to work on the details. Many of the small parts are 3D-pinted and are used to then I cast silicone moulds.





With those parts I started the detail work - e.g. the front hatch with a small periscope:



The assembly for the back snorkel:




And the details on the conning tower:

Currently I'm working on the moulds for the rudders. They are based on models made of soldered brass:

That's where I'm at today:

That is lovely work.

How did you get the original hard foam milling done? Did it cost much?

Congratulations on the build.

David

A friend of mine has a company that produces carbon and glass fiber products, and he has a 3D mill. I got the milling as a return for a favor. But I think it would have been comparatively cheap, as the hard foam allows high feed rates and thus costs little machine time, the foam is cheap and you have no wear on the milling tools. I had the CAD data ready for a CAM programm, so programming was also not a big issue. Milling in resin e.g. would have been very, very costly. I know, because that was the firts idea, but quotes I got were all in the 3500 Euro range. Not attractive at all.....

It is very interesting to see how this technology works out. A pity it is still expensive.

Would the Euro 3500 option have avoided the need for the first positive mould perhaps?

David

Most probably yes. You can directly mill negtive moulds in resin blocks, but they are not as durable as conventional moulds that have a very hard surface due to special mould resisns.

the moulds look great you must have a lot of patient,s
i will admit i dont know much about moulding things i will need to have a lesson on how to do hydroplanes and rudders if i build the deans marines HMS Resolution
im watching with great interest

take care geof

I do n ot have too much time to do the build, so patiece comes easy.....

It's the first sub I build on my own, so I'm also learning allot.

Cheers Andreas

Took three tries to get the ruder and the hydroplanes right. New moulds are often a bit tricky. But now I'm quite pleased with the results. Brass shafts and glass fiber / carbon fiber blades. Rock solid.....

Lovely stuff!
Thank you.

David

I wish i could biuld that well looks great keep up the good work
Geof

O.K., slow progress, but progress.....

The front servo will be located in a smaller tube attached to front of the main pressure tube. To be able to install and remove it, I have located it on a mount, that can be pushed over two thread rods and that will be secured by two M5 nuts.







The brushless motors have watertight feedthroughs that just get mounted in the motor flange and that are secured by a M18 nut. The feedthroughs are custom made.







And the pre-assembly of the tower is finished, too.