PDA

View Full Version : SparrowHawk pod shake cure


StanFoster
03-18-2006, 02:31 PM
I have heard of several SparrowHawks having resonant pod shaking problems...even though the cabin and cyclic are fairly smooth.

That was my situation. First of all...I havent so much as checked my blade tracking yet as the cabin and cyclic are smooth as I have ever had. But......that pod was shaking too much....the compass on top was not usable. It has a lot of mass to it....plus its mounted on a long arm.

I came up with a quick cure that fixed the pod shake very nicely. I still am going to play with my blades when I get more time.

I cut a 1 x 6 poplar block of wood.....fit it very tightly between the pod and the nose of the cabin. It is attached to my heater mount.....and I bolted it to the front of the pod. This block stops the fore and aft vibrations...and since it it 5.5 inches wide....and real tightly fit...it has much authority over the lateral vibrations as well. I painted it to match my interior....and I was pleased with the performance and appearance.

Stan

Harry_S.
03-18-2006, 02:49 PM
Good fix Stan.

Anything free standing is gonna shake if the base it's attached to...shakes. Even more so.


Cheers :)

automan1223
03-18-2006, 03:25 PM
Stan, I would not go crazy. Hawk guys are using a vertical compas card, I do not know if it is electricly driven or just counterweighted. The compass in steve mcgowans sph is fine. most compass in rotorcraft just like to twirl around anyway.

Jonathan

rgraffeo
03-18-2006, 03:56 PM
My compass used to spin while flying.
The old mechanic at the airport filled it completely with lamp oil & got all the air bubbles out, now its steady as a rock.