VStabi Pioneer of Flybarless

Possible reasons for tail wag, oscillations and not crispy stops:

Everytime when a heli shows worse tail performance after a crash repair or also during its lifetime you should think "this has been working perfect before with the same settings in VBar" and this is why parameter changes may increase the problem but you won't get rid of it.

The only thing that may help ... back to the bench and check the complete tail:

- The assembling of the tail must match with the manual. Check especially the leading / laging blade grip linkages, changes here will effect unuseful throws on both sides.
- The rotating direction of the tail rotor should be correct
- check the torque precompensation direction. Using a preset and building the heli as recommended there it must match. For other helis check on your own, should give more tail thrust against the torque with more collective pitch.
- the tail blades should have 2-3 deg against the torque in setup mode, stick centered
- check the tail throw for aerodynamical limits. Too much tail pitch will provide stall effects and you may see a very soft stop after a pirouette.

If you have found nothing here, disassemble the tail:

- unhook the tail linkage at the servo horn and check the complete linkage form servo to the tail slider for smooth running. If it goes strong, figure out which part it is and repair it.
- check the tail slider for smooth running. As usual the brass slider does not need any grease or oil. Indeed using grease or oil will have disatvantages, sand or dust may stick on it and the tail goes stronger. Even when oil gets older we have also a strong tail. Clean it with a tissue (move the slider back/forth a couple of times) and it will run smooth again.
- disassemble the tail blade grips and their bearings. Check the bearings, especially the thrust bearings can be damaged with chatter marks and the tail won't work soft under load.

Using a Logo heli there are a few more known points:

- disassemble the tail shaft and insert it with the bearing-sided end into a drill
- sand the shaft down with fine sanding paper, the factory diameter is about 5.98 mm and you can sand it down to 5.92 .. 95 without any problems. Don't sand on the bearing sided end because they won't fit tight enough afterwards.
- deflash the brass slider. On the thinner side of the slider (not the one with the hexagon head) there may be a small burr inside. Use a small round file, move it from inwards to outwards to get this burr away.