aerodynamic18

Hi all just to let you know how im getting on since the 'bearing episode'. Have been practicing alot at a new field i found and have got a lot better since even had a go at a piroete(hope thats how u spell it). but the only thing has been is that there was a bit of vibration on it but i think my main shaft is slightly bent so i am about to repair it and i will hope that this fixes the vibration for good. But the more important question is at the minute i am using a standard piezo gyro in the caliber but when i am hovering sometime the tail will flick out for no reason but i an catch it and then it will be fine for a while and then it will flick out again. so what i was thinking was if i put a heading hold gyro in it would this help it because the only other caliber ive seen flying had a heading hold gyro in it and it was fine. so is the gyro ok or is it being affected by vibration from the main shaft being bent, is it malfunctioning or is it something else all input would be appreciated

davidj

you are probably getting engine pulses. If the engine is not running smooth it will cough and result in a power pulse which will affect the tail. A good HH gyro will help but when the power is not delivered smoothly nothing will stop tail twitching.

Vortexgen

Also, the caliber has a tendancy for the tail to flick (slightly) with the HH or NORM gyro, when the tail rod guides are not perfectly alligned.
this condition is only a flick of about 5-10 cm of the tail though, if it spins substantially it is usually as Davidj says - the engine.

The reason the flick occurs if the rod guides are not alligned correctly, is because the rod will bind with the guide, the gyro tells the serv to use more input, suddenly it overcomes the binding condition and the tail flicks.

To check this, simply pull of the rudder servo horn and feel for any friction along the guides. After any crash/heavy landing, it is not uncommon for the guides to move slightly.

As for your main shaft, not sure how you will repair it (hopefully replacement), but you can check for straightness by rolling it on glass.

Midland Helicopters (UK) have an upgraded shaft thats stronger than standard for your info.

hope this helps, good to hear you back in the air........

davidj

I got around this by making a carbon rod that is free from the servo to the tail.

Vortexgen

Thats a great idea davidj,

no doubt on the servo end of the tail rod, you have got rid of the Z bend and placed a rod end, and fitted a ball to the rudder servo horn.

I would like to know if you have ever had a problem with fitting rod ends on to an unthreaded rod, and what method did you use to attach it ( crimpping, or glue or ?????) I would like to do the same to mine but fear that the torgue on the rod during aggressive flight may pull the rod end away from the the rod.

randy41

Not sure if you guys have anything in uk like the below
link. But us USA guys do.LOL I called helliproz and they said
the rod(below link) was a perfect direct T/R push rod for the caliber 30. Its a little priceee. They call it MrC Tail Pushrods, CF, Blue .

carbon direct push rod for tail rotor

davidj

With a 30 size ship I use 4x40 threadded rod and make it about 2 1/2 " long and use JB weld to glue about 2" into the carbon rod. In the past I used 3x32 rod an it broke (sheared) several times. I use the 196 carbon rod and the big rocket city links that will take the 440 rod. If you want you can take some thread and wrap the end of the carbon rod and use CA to cure it to the rod to help strengthen the end of the rod. This method is fine for any 30 or even 50 size heli. I would not do this for a Fury Extreme with a 601.