This page is where I'm going to publish items which will help you get the details correct. Typically it will be things not covered by the magazine, or are causing confusion. Most of these will come from other people as there are many out there far more knowledgeable about the Bismarck than I am. I'm a modeller, not a historian. However, I will only publish items that I am reasonably confident are correct. Of course, I'm not going to guarantee that everything is correct, you use the information at your own risk.
Radio Control installation
Prop shaft and motors
I'm also going to detail how I install the radio control equipment. The Amati design has the prop shafts angled down slightly, but I'm trying to modify the design to get them parallel to the keel, as they should be. I'm trying to do this using the Amati/Hachette supplied equipment as far as possible, with as few additions as I can get away with.
First off, a warning. I'm deviating from the instructions, and this may all go horribly wrong. The model may not perform well with smaller props that will need to be fitted. If I get the alignment wrong the shaft will vibrate, possibly wrecking the hull. Needless to say, if you try to follow my example, you do so entirely at your own risk.
Week 14 : The first problem is that the angle of the shaft is determined by how low the gearbox can be mounted. With the hull as designed it won't go low enough. So it's out with the saw and knife and the seemingly drastic task of cutting out two holes in the keel plate. The result is that I can get the gearbox 4mm lower, which should be enough to get the shafts at the right angle. While this sounds drastic, it shouldn't be to concerning. I still have the two thicknesses of planking to give the hull its integrity. The only concern is that I've weakened the hull right where the motor goes. However, I can reinforce this with a sheet of glass tissue and resin to put the strength back if necessary. It's not a high powered model, so this shouldn't be problem.
Here are the cut-outs I've made.
The next challenge will be to shorten the propshaft tubes, so only the shaft runs outside the hull, again, as per the original. This means that I will need to construct a strong, fully functional A frame just forward of the prop, complete with a bearing to take the radial load of the prop. This is probably the hardest part to get right, as it needs to be strong, securely fixed to the hull, and lined up perfectly with the prop tube in the hull.
At around week 60 I received the shafts and gearboxes. Here is a picture of the gearbox and shaft in place. Unfortunately it is rather close to the side of the hull, and the outboard mounting bracket interferes with the planking. My solution is to simply cut off the offending part. The gearbox is rigidly fixed to the prop tube, so no flexible joint is needed. I reckon that if I glue the shafts to the hull securely, the gearbox doesn't actually need to be fixed at all. The tube is a tight fit in the gearbox and should hold perfectly well, so the mounting brackets seem a bit unnecessary to me.
Here is a close up of the gearbox.
This photo shows how much I cut off.
Looking from the outside you can see that I have managed to get the shaft parallel to the keel. I checked the position against some reference info of the real ship, and it is actually a little bit too low and a bit too far out from the centre line to be in exactly the right position, by about 2mm in both directions. However, this has given me an advantage in that I can still get a 30mm prop to fit without fouling the hull. If the scale props fail to perform, I can still swap them for the Hachette supplied ones.
The shafts are not going to be permanently fitted for quite some time yet. The still need to be shortened and I've still got to make some A frames.
Elevating the barrels
I've worked out how I'm gong to elevate the barrels by radio control. Firstly the assembly of the turrets is changed somewhat. Most of the wooden structure is no longer used. Mainly the base and a couple of the upright parts remain. This provides enough structure to pivot the barrels. The barrels will be moved by a micro servo. The one I've used is a 4.3g servo.
The photos below show a rough bodge I did to check that it would work and all fit in the space. The guns are represented by coffee stirrers, and the shaft here is a 2.5mm dowel. This photo shows the pivots and barrels. In the final version I will use a metal shaft which will be located in some miniature ball races pressed/glued into the wooden uprights.
Here are the remnants of the uprights at the rear. These are needed to hold the rear section of base in place.
The servo is simply glued onto a couple of spacers which raise it so that it clears the rear uprights. The pushrod is a piece of 0.4mm brass wire I had lying about. I shall probably replace this with a piece of piano wire which should be a bit stronger.
Here is a side view showing that I've got plenty of clearance heightwise. The servo arm just needs cutting back.
The pivot for traversing the turrets will be made of a brass tube. I shall run the servo wires down the centre of the tube which will mean cutting them are re-connecting after the turrets are in place.
The brass cover is made without using the wooden structure. Firstly I taped the metal parts together with masking tape.
Secondly, I cut up strips of cotton (an old hanky) soaked them in superglue and glued them over the joins. This has re-enforced the joints nicely and the finished turret is remarkably strong. Of course, this is a quick bodge to see if it would work. I'm pleased to say that it did. The final version will be much neater.
Here is a video of the barrels elevating, with and without the brasswork. The only thing really left to do is to limit the servo travel. At the moment the travel is too much I may do this with an add on electronic gadget, or possibly by configuring the servo travel in the transmitter, if I buy a fancy RC set to operate all the extras. (Those who know me will respond, "What do you mean, IF ?")
I'm going to modify the turrets so that I can rotate them by radio control. I'm not quite sure how I'm going to achieve this yet. Possibly by modifying some servos, or possibly by fitting some 3:1 gearing so that a 90 degree servo will drive the turret through 270 degrees. I'm going to wait until I've seen the actual turrets before I decide.
Week 46 : Turret Caesar sits on the aft superstructure. If I'm going to drive the turret I will certainly need a shaft to drive it. The hole in the barbette is 1/4", or just over 6mm. I'm thinking along the lines of fitting a 6mm shaft to the turret, and some sort of drive under the deck. I have some 6mm bushes left over from an RC car, which should be just about right to support the drive shaft if necessary. Anyway, I'm getting ahead of myself. All I need to do for the moment is drill a hole through the superstructure. Now I've got the barbette I can use that as a guide to get the hole in the right place. It's drilled out to 7mm.
Copyright note. I believe that all these photo's are either free from copyright or have been sent with the owner's permission to publish them. If you own the copyright on any of these pictures and does not wish them to be published please let me know and I'll remove them.
Illuminating the Search Lights
Putting little LED's into the search lights to make them work was too tempting for me not to try. It was surprisingly easy too.
I got some 1.8mm high brightness LEDs and some 100 ohm 0.25W resistors. These came from Rapid Electronics
Note that the resistors come in packs of 100, but at 50p per pack, they're not badly priced. The 100 ohm resistor is right for a 6v supply, but you'll need to re-calculate it for any other supply voltage.
I drilled two 0.8mm holes in the back of the search light housing, and pushed the LED in.
The wire sticking out the back of the search light was bent down to follow the line of the mounting. This will later be bent with a bit more care, glued and painted, making it inconspicuous. I'll drill holes in the deck and run the cables through the superstructure where they will be hidden. The resistors will be in the superstructure somewhere.
Finally, with the lens in place.
Now, apply a bit of juice, and .....
Impressive, isn't it ?
I shall paint the inside of the search light housing black, to make it opaque, and then silver to reflect more light.
A word of warning, these LED's do produce a bit of heat, and they are completely enclosed when fitted in the search light. I do not know if they will get hot enough to soften to plastic if you leave them on permanently. I shall only use them intermittently, just to be on the safe side. As with all mods, do this at your own risk !
Wiring wise, you want one resistor in series with each LED. I'm going to use an electronic switch to switch them on and off with the transmitter. It may be prudent to put a fuse (0.5 or 1 amp) in the circuit, just in case something shorts out.