Thread: Italeri 1/35 S100 Schnellboot build and R/C conversion

Originally Posted by Mighty Finn

Good luck with the project. I am doing the same but bottled it when deciding to motorise all 3 shafts because of the cost. Decided to fit a shaft to the mid engine and have the outer ones as dummies. For any one else thinking about this kit it is outstanding and cannot fail to attract after-market sales with etched brass etc and of course Italeri's crew. Hopefully mine will be ready for the water for next summer. Meanwhile the wife has hidden the credit card following her comment "Well once it's in the water no one will be able to see that detail anyway". Women! they just don't get it do they.

Definately going for the 3 prop set up. I also want to fit a water pump, but havent got round to looking into it yet. I guess i am on the same schedule as you as far as build goes. Hopefully for the summer!

Made the prop shafts today with various gauges of brass tube. Cant help but get the feeling it's all going a bit too well!.
In the pictures below you can see the dry fitting, before i fill the shafts with grease.

Finished off the prop shafts and fitted brass bushes inside the outer prop shaft supports. Then on to fitting the rudder assembly, once again with homemade shafts. As with my ViiC u boat i built a while back, i am using as much of the original kit as possible.
The rudders were easy enough, just a matter of drilling the correct size shaft hole. This can be a little tricky getting the hole straight, using a mini drill vice and continuous checking is the way forward. "turn- check its straight- turn- check its straight,so on"

Another busy couple of days in the loft. When making your own prop shafts from brass tube there is always a risk that water will seap up the tube even if full of oil/grease. This risk is always on my mind, so to try and protect the expensive bits that will be going into the S100, I have decided to fit a bulkhead that will when fitted seal off half of the boat and also hold the motors in place. So that it can be taken out if need be, i have decide to screw mount it, then seal the gaps with silicone sealant (The silicone will come off easily should i need to change a motor or two. I will also be fitting a water pump which will be float activated as a secondary precaution.

I thought the steering mechanism for three rudders was going to be a nightmare, but in fact it turned out to be quite easy once i got my head around it. The rudder control ends have been made from brass sheet with some old pinion gears i had lying around, soldered to them. This assembly is then locked onto the rudder shaft with the opion gear lock screw. I would normally just solder an arm directly to the shaft, but for this model i want everything to come apart easily should it need repairing.

The mounting of the rudder servo is also done so that both the support spars and servo can be easily removed.

DISASTER!!
A couple of days ago i did a bath test to check she was water tight and to test out the motors and rudder mechanism. All seemed fine at first, no leaks. Then i tested the motors, slowly at first.....then gradually increasing the power.....all ok so far. Then i let her have full throttle. After three minutes at full throttle i could smell the cost of 3 motors go up in smoke :(
The small motors i had put in all burnt out. I had an idea that they would not stand up to the friction that the long, grease filled, prop shafts and water resistance together would cause (More so the tubes).
I have now installed three RS380 motors and these (although overkill) are doing the job nicely. When i bath tested them the s100 shot acrooss the bath and the bow ended up half way up the bathtub wall!! :)

Torpedo tube doors.
I have now designed the torpedo door opening mechanism. After a lot of fiddling about i have managed to get one of them working, the other i will attch the same way off the same servo. video here - YouTube - torpedo tube door mech.3gp
In the photos below you can see the battery mount (Nice and low), the rs380's and the torpedo door mechanism.