Well, I finally decided on my next project: Overhaul the Schnellboot Wiesel.
I bought this Graupner kit in 1975 in London while we were doing some European travelling. Started working on it until "the kids" came along. I placed it in my attic (bad choice with the heat in Florida) then decided to resume working on it again in 2003. By then there was a lot of new information and photographs on these Zobel Class type 142A Schnellboots. So I decided to rip it apart including the conversion to four motors and shafts. That required making a large part of the aft under hull off.
At this time I decided to change the interior access cutout. This was a massive rectangular cutout leaving long seams with hold down levers. I decided to re-cover the deck and make several individual cutouts avoiding almost al seams and making the deck/hull stronger. The down side is that it makes it harder to access the inside components.
Skip forward a few years and it was complete. The first run was in January 2012. The boat looked great but the performance was pathetic. Those little conventional shaped propellers would not make the boat move very fast. For the next few years I would bring it to model boat meets (back the the Bay Area Electric Boaters). I had only two RC boats back then, Wiesel and my Standard Oil tug. As I built more boats the Wiesel dropped out of the picture.
How could I do that to my best looking boat?
In 2018 I got my first 3D printer. Upon finding a photo of what the real Schnellboot props looked like I thought that the model needed this upgrade. But with scale boats and tanks I had no time to complete the mission. Even my upgrades fell behind and my "to Do" list grew.
So, yesterday I had to make a decision: Which would be my next project? (Last month was the 51st anniversary since I bought the kit,) So the Wiesel won the lottery and I am going through everything, stripping out all of the electronics. It will take a little while in converting from the old style to the newer, more compact and direct wiring.
The first thing I am working on is getting the Loran turning again. The modified servo stopped working and it was embedded into the superstructure.
I am attaching a few photos for you to view.
Sorry US Coast Guard Cutter, Fireboat, Towboat, and Frederic Mistral tug. Sorry King Tiger, M26 Pershing, M10 trailers, M1 Abrams, second King Tiger, Deuce and a half, Semi- lowboy, and boom crane. You will have to wait in the queue.
I also have more on the Wiesel in my harbor here on on my web site (see link).
Lew

https://www.rcflorida.org/lmb/lmbwiesel/

Structure: Replaced the gear mechanism that turned the navigation radar. Will be adding a Buck circuit to run it off the RC battery instead of the separate AA battery.

Hull: Got into the hull and stripped out all the rest of the electronics, motors, shafts, and rudders. The Graupner speed 300 motors apparently do not have the torque to turn the shafts so I just ordered six 390 motors. These are slightly larger in diameter but much longer in length, putting out more torque. Can't go to bigger diameter motors because of space issues.

Hull: Fitted the new 3D printed propellers, what a difference! Photo show two of the four props installed.

Rather than those almost daily updates, I will post major milestones on my Wiesel overhaul. Step one was to completely vacate of all electronics and moving parts from the hull except for the steering servo.

This afternoon I finally got the four new motors (new 390's, old Graupner Speed 300's) installed (1st photo). Just couldn't fit the assembly into the hull and had to cut about 3mm off of the flange around the opening. Tested them and they turn the shafts and props real well. The 300's were almost dead and they did not have the torque to turn the shafts even out of the water.

Working on the connections on the motor control plate (2nd photo). The photo might be deceiving as the motors are down in the hull and the motor control plate is sitting on top of the deck for now. I'm staying with the idea of running the outer motors (1 & 4) off the two ESC's (Mtronics Marine Vipers 25). The center two motors (2 & 3) will run off a relay turned on by a channel switch on the the transmitter. They are forward high speed only.

The rear turret mechanism works (photo 3). I 3D printed a mount for the Futaba micro-servo that has 1:2 gearing to increase the sweep of the turret. I might consider a circuit to slow down the speed of the servo later.

Once everything is done I will see if I need to upgrade the planned batteries from 7.4V Li-Ion 3000may to more capacity, perhaps 5000mah. Originally I had 7.2V NiMh 5000's (two of them).

Lastly, the schematic (photo 4): You can see three batteries, one for powering the receiver which also powers the radar and the power for the secondary relay through the primary relay (didn't want the draw through the receiver for that). One battery for the primary motors (1 & 4), and one battery for the high speed motors (2 & 3).

Tanking some time and a little difficult working in the small openings (photo 5) in the deck (unlike the Graupner idea of a very large ugly opening).

Lew