Severn from Airfix and RC

Hi all and happy new year!

After an exhibition with a few other german lifeboat enthusiasts I decided to add another scale to my 'portfolio'.  Also needed some rest from the tyne+boathouse+slipway project.

As space at home becomes rare 1:72 may be a scale to build also boats which won't fit in 1:20 or even 1:10. 
The last plasticmodel (besides the semi ready Walter Rose) I've built.... 30something years ago.

For the Airfix Severn Kit there are a few blogs and reports describing the RC modification. All have just one thing in common: LOOSE WEIGHT!

The Airfix box arrived with a lot of details- in other built reports, it should have 110gr at the end and still runs well with 129gr. Unfortunately the blog example of hull, deck and upper part showed about 10g LESS than mine. I have the grey material, the other was white .... or I was too carefull scratching out material. 
Does anyone have an idea if they really differ?
With scratching, cutting and grinding teh hull I won somehow 5-8g (I gave up checking at the end). As a RC modeler, RC comes first and then come details. But usually not all details can be seen or will be recognized by just 0,1% of the people.

So my idea to win more grams is making the cabin as a insertable part, so in case I want to run full speed, it just can be taken out of the superstructure. Gives another 8g less weight. For display or when only slow motion is needed it can be inside and illuminated.
I plan running the boat in calm waters but as it's together with the 1:20 brothers and sisters the option of putting it into the big water should exist. Therfore I buid some extra parts for having a coaming around the open deck.
grinded hull:
 

thin, but not thin enough, I guess...



Leaving the build plan towards RC:


The first step for a supertstructure to take off.
Joerg

Hi,
I decided to take out the cabin but leave the front part as additional part for exhibitions.




It can be stuck under a thin plate in the front and the back is held by mini neodym magnets.





OK, 1/72 and especially RC in that size was totally new to me.  The 1/87+H0 scene has a lot of developements over the last 20 years. Main change: just powering with 1S accu, preferably LiFePO4. So new accu cells, now loader board (my loader just starts with 2S) no KSQ as they start working from 4V on... all the light has to be done with resistors ... smd resistors in the size of... almost nothing...
Fortunately one can get RC electronics in some shops. Motor controller for 10€ running with 3.2V etc. Nevertheless it sums up as nothing from the parts in stock could be used. Except for my fs2a 4ch receiver for my flysky i6x/s.
4ch only limit the functions. For the Severn the will be limited anyway because of the weight.

So: 
Motor control
Rudder
Switches (5times --- light sections + radar)
bow thruster!

Best,
Joerg

Yeah, the bow thruster.
Basically not so dramatic, takes a while until it works because of the limited size of the parts:


the advantage of 3D print: if it*s too large just print it smaller.


Very easy construct, just a rotating plate on a 4-6mm motor (from a toy helicopter)

Both tests with 1,5V

https://www.youtube.com/shorts/auzuqKb7IPU

https://www.youtube.com/watch?v=Y_gskFtAQXM

OK, that was it for a while. Mounting motors and light etc. you have only one chance and correctiona may create larger damage, also some modifications need to be done before further building the superstructure.
Therefore I decided to build an easy springer tug in 1/72 just for learning....
Well .... you know how it is when creativity takes over.....



A springer tug with one barge, built by hand and 2 printed version as well as a ponton .... crew for tug and Severn....
If there is interest I can write about the tug too.

For the Severn:  There were mainly two options used for the steventube ('Stevenrohr') and shaft, either some shaft bearing (copper or brass tube on the tube ends)  or simply soldering tin with a hole for the shaft.
The tug has a 1.2mm inside opening of the tube with soldered ends, grease inside. For the severn I ordered 1.5mm inside tubes plus end parts of copper. Againg there will be a grease filling tube soldered to both.
Propeller may be printed 3D. Motors will be 7mm 12000rpm micromotors running with 3,2V. 
Coupling will be a ballpoint writer spring with mounting ends of brass (handmade by a friend).

I will finish the tug first (light and radar) hope to have the severn at least running in early april.

Have a nice and healthy 2023.

Best,
joerg

Hi Joerg,
You have been a busy boy.
Well done,
Very interesting.
I like the way you art trying to loose weight on the Lifeboat and the Bow-thruster is good too.
Keep up the good work.

Martin.