I hope this belongs here and not in the electronics subsection, if not, I am sorry!
I have posted here a few times, looking for a way to have a gun recoil in my STUG III using the Taigen V3, because I didnt want to break the bank and get a new board. Thanks to the very helpful people of this forum (Special shoutout to Jofaur86) I have finally found a way, after not having any clue whatsoever when I started this whole thing, wich I wanted to share here, thinking it might help someone else.
BIG DISCLAIMER: The first part is mostly about electronics and a kind of like a guide. Because I found it very hard to find all the information I needed I wanted to share all i have learned here, but you need to understand, that I still dont have much of a clue what I have actually done here, so it might just be, that I have done something that would under slightly different circumstances damage your tank. If some of the more experienced builders notice any Problems with my setup, please tell me and I will edit, or delete this post, before someone follows these instructions and damages his electronics. If enough people say, everythings all right, I will remove this disclamer.
As you might have seen from the titel tho, I have not only added the recoil, but also managed to modify my STUG to have horizontal gun movement.
Heres a little summary of what I wanted to share:
- Recoil electronics
- 3D printed elevation bracket with horizontal axis
- Video of the final form
- Some thoughts on problems wiht the design
Lets start with what my original goal was, to add a gun recoil to my Taigen V3:
The key to this was this little board, wich sounded like exactly what I want, but I just couldnt figure out how to make it work until some friendly people on here helped me out:
https://www.rctank.de/Taigen-Signalwand ... hrrueckzug
This is how it works:
1. It needs power:
The 2 pin connector you can see on the picture needs to be connected to a power source. I just straight up connected it to the Battery, the same way I have seen it be done on the Taigen Youtube Channel. One important thing to note is, that the polarity of the cables is important, otherwise you kill the board! (Been there, done that) The red cable of the Battery must be connected to the outer pin on the servo board!
2. It needs a Signal:
This is the Part I had problems with, mostly because I didnt understand how the normal Taigen board works. What you need to understand is this:
If you move the left stick on your remote upwards it gives power to your "gun". If its a BB Unit it will make the motor in there turn, moving the Piston in the gun backwards, spooling it up. Once it is all the way back, it pushes a trigger, wich connects two wires. If that circuit is connected, you get the sound from your speaker and optionally the track recoil, but with the recoil board mentioned above you will also want to connect the signal wire to this circuit. That way, once the circuit is closed, the Servo, wich can be connected to the board, will be activated.
Problem now is: If you dont have a BB Unit, pushing up the left stick doesnt close said circuit. This is where you will need a relay like this:
What this does is essentially the same thing as the BB Unit, just quicker: Once you give Power to it, it closes a circuit, easy as that.
Heres a little schematic I drew of the electronics, hope this helps with understanding my explanation:
Now on to the horizontal movement!
My goal was to design a new bracket, wich allows me to move the gun horizontally, while still using the same elevation motor the BB unit uses aswell and without any Servos obviously, because the Taigen V3 cant control those.
First of all, here is the "finished" design (Added the " because it still has some flaws, wich I will explain later)
For the Horizontal Movement I used this motor:
It works perfectly. At first I had the fear, that it might be too strong, as I had no grasp for how to judge the tourge figures, but in reality, once the Barrel reaches the maximum angle it just stops without any ugly noises, or shaking, even if i continue to push the stick to the side.
For the vertical movement I used the same motor, as the BB Unit, I just had to do a tiny modification.
With normal Taigen Tanks the turret rotation is controlled by moving the left stick left and right and the vertical movement is controlled by moving the left stick downwards, wich will make the turret go up and down periodically. With the STUGs elevation motor you cant do that, because it has a little plastic bump on the arm attached to it, wich blocks the motor after half a rotation. You can simply take a knife and cut that nob of, wich allows the motor to freely rotate 360°, so you can wire it up like any other Taigen Tank.
Here is a picture, of what the upper hull looks like fully assembled:
And here is a video of the final result:
https://youtube.com/shorts/cDxAtDQBfA0?feature=share
Now to some problems:
1. As you might be able to see in some of the pictures the 3D printed bracket flexes quiet a bit. This is probably easy to fix by just adding some supports underneath, or just print the one piece with supports added to it from the beginning, I just didnt get around to do that yet.
2. The way the Servo is connected to the Bracket: Well its just glued on right now... As you might be able to see I added two pillars on the one piece to screw the Servo into, but they broke when I tried. Making those wider would limit the treverse, so that wasnt an option. I would have to redesign the whole thing, make it longer to be able to make those pillars bigger, wich I just didnt have the patience to, so glue did the job just right.
3. The traverse isnt nearly as wide, as it would be historically acurate. In rela life the STUG III would have an Arc of 24° (12° each side). My model only has about 12 -14° in total and I dont see a way to fix that, if I want to keep the elevation motor. I would have to move the axis for the horizontal movement further towards the mantlet, wich I just cant do, because of lack of space, so it will just have to stay this way.
Now that was all I wanted to share for now. In the forseeable future I will repaint it, because I have also added some new sideskirts and am not happy with the current paintjob in general. I might post that here aswell, but I dont feel like my skills at painting are anything worth sharing really.
Thanks for reading this!
Good evening, great job, especially for the horizontal displacement!!!! for the servo? yes more complicated than with a BB shooting system, in fact you just have to send more 5 volts on the input concerned, either with a relay or bun servo and a micro switch, your solution, and in addition from the TX of origin, which is easier with a standard TX, well done for your work, and thank you for sharing, the forum is made for that 
