Hi everyone,
I already have about three different ft projects I'm currently working on, so I started another one
This is a model chopper that can actually fly around in a circle. It can hover, go up and down, and steer backward or forward depending on the tilt angle and rotor speed, just like the real thing. A slip ring transmits a variable voltage to the motor, a counterweight keeps balance, and the tilt angle is controlled pneumatically. The initial idea came from an arcade game I remember from my childhood. My research showed there were several similar games at that time, and the Jaycopter seemed to be a good starting point, so I used it as a reference.- IMG_20250806_175904.jpg (984.48 KiB) 749 mal betrachtet
One of the biggest challenges was providing an effective way to tilt the helicopter nose-down and nose-up. My first attempt used a servo and two slip rings, but the whole thing was bulky and, as I feared, the servo became erratic and it never actually worked properly. The original game uses a cable similar to the ones used to transmit force to bicycle brakes. I don't have one, and could not realize a way to do it with ft. But... Thinking about the principle by which these cables work, something came to me: pneumatics! First I inserted a cylinder across the turntable hole, then tried all crazy ways of making the thing rotate. I used pulleys and gears, but it was very unstable. I also tried a slewing ring, but friction was prohibitively high. In the end I was able to make it work, albeit in a different way. A freewheel hub is attached to the turntable so the metal axle can travel up and down freely, and the cylinder simply goes on top of it all, attached to the axle via a clamp coupling.
In this project, friction is a major concern and must be reduced wherever possible. The classical fischertechnik way to transmit current to a split ring consists of a spring base 31307 attached to a block 15 (or spring-joint block 36223) and two metal contacts 31305, but this arrangement offers lots of mechanical resistance and the chopper would rotate very slowly around the central axle. Then I thought about some way to make flexible contacts, so I tried segments already cut from damaged drive springs 31028. (I assure you, no functioning drive springs were harmed in the process.) After a lot of tests, I found out that the rims of the metal rings are ideal: they show considerable less friction, and are also able to cope with the occasional wobbling from the slip ring. Now the helicopter can rotate freely.
- 11_c71adce4.jpg (716.17 KiB) 749 mal betrachtet
The project is completely analog at this time, and it's already a lot of fun. But the original is actually a coin-operated game, complete with a timer, three landing pads with electrical contacts, tree-shaped obstacles, some logic to sense whether the chopper landed correctly or has hit an obstacle, plus a panel with indicator lights. (Some models even had numerical displays and more sofisticated targets.) This is much more complex to do, and I think this project would look very cool with ft relays and logic Silberlinge modules, but I don't own any of that. My version will probably use a digital controller.
Let's see.Video
Here is a video so you can see it in action. I also have several other pictures and a list of parts that I'll post later on.
Best regards,
Rubem
