Tried to run diamond dust today. 50 jett fire, futaba gear. Tremendous interference directly proportional to throttle. Only able to eliminate by holding reciever in my hand. Anyone had similar problem. Channel 26, 9303's,3001 throttle, pipe,250mah pack, heavy duty switch.

It would seem that your problem is vibration related by what you are describing. Try a another receiver.

The reciever was a brand new futaba. I have put in hitec 555. It allows room for more padding. Havent ran with new reciever yet.
The plane does not really vibrate much at all but must be enough to cause this.

Where is your antenna running? I know the DD has two C.F. tubes within the wing section. It is possible to pick up interference from the tubes, since they can capture RF signals. Be sure the antenna doesn't run parallel to the tubes...Are you using any type of metal to metal linkages on the setup. The RF they create can also be amplified by the tubes. From what I understand, some of the channels are more likely than others to suffer from this type of interference...Hope this helps. Dan

I used the antenna tube as in the plans that circles around the inside of the entire wing. I also pulled it out and ran it straight out the back. No difference. I am on 26 and the new hitec 555 is also on 26. Ill try a different channel if the new hitec does the same thing. Thanks.

To answer your question...YES there is a LOT of vibration in a dust powered by any high RPM engine. If your prop isn't perfectly balanced it gets worse. I blow three throttle servos (all on the 2nd flight of the day) due to the balance of the prop changing after a little wear on landing. I now keep extra props and put a spring relief on the servo arm.

Mark M.

Any special method to balance the props for high rpm applications? I have been using a simple gravity setup.

Just use a magnetic balancer and make sure you can stop the prop at any angle. It takes time and don't breath on the prop while you are doing this. The effort is worth it. BTW, your receiver may need service now.

Mark M.

Three things:

1) Futaba receiver? That's a big unit, how do you get it in there? Use an FMA Quantum; tiny and totally glitch free. I run my antenna out the bay, counterclockwise into the right wing, in front of the fuel tank, around the inside of the left wing then up against the center bay and out just ahead of the left elevon near the left fin. Never a glitch with the FMA Quantum!

2) Throttle servo. Needs to be vibration isolated. Use a nylon clevis on servo and throttle arm. These are threaded on short pieces of threaded rod that go into a big piece of inner nyrod in the middle between the two pieces of threaded rod. No vibration problems. I have been using a cheesy FMA S-100 on throttle with no problems in over 150 flights thanks to this vibration isolation setup.

3) What's with the 250 mah pack? You'd be lucky to have enough juice for one flight. You are running powerful, coreless, metal gear servos that take a lot of juice. If your pack is weak it is entirely possible your problems could be lack of power. Best to use an 1100 mah pack with those high-torque servos and have power in reserve.



You shouldn't be having the problems you are having. Hope this info helps.

Thanks for the great post. Answers alot of questions. Not easy to get futaba reciever in and only room for small battery pack with it. Is that fma reciever the sub micro model? I was afraid to use a micro or submicro due to range problems. Test tomorrow with hitec 555 (i have one on hand, will order the fma for the whiplash), 1100 pack and isolated throttle servo and see what happens.

jlong,

No, the Quantum is a full performance receiver. Works great, no glitches even in a high noise environment. Very tiny unit, fits in the Dust with no problem.