Rune

Hi guys
I have been flying a Spark so fare this season and are wery happy with the plane and the way its behave.
It has been just one thing I really havent like with my setup ...noice.... it sounds as it had been some vibrations special when I have push the plane on the rudder, so I decide after last competiton to remove the engine and what it was hard mounted on and replace the mounting with a soft mount .
And I have to say ...what a difrence..I have used 4 normal 10x10 mm rubber mount and a "hard" mount into the rear bearing .
The first time I activate the esc I didnt think I got it activated as I didnt hear the low noice form the engine when it activeted.
SO all the horribel sound for the motor is gone!
Sorry I didnt take any pics but its a really easy mod, Its a ring in the front in 2mm fiberglass this is glued into ht nose about 6mm behind the front to leave room for the bolts and one ring wich is mounted to the engine and rubber mount between those rings, I had to make a new distance ring to the engine so I got the prop 5mm more away from the motor.
the back mount I had I still use just found some plastic rings to get it about 5mm futher backwards.
So if you have problems with noice like I did ..give it try.

Jetdesign

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Can you give some more details about the rubber material? I am interested in material/thickness/hardness etc.

It has been my experience that choosing the right rubber compound is not a trivial task. You don't want it soft enough that things are moving around, not so hard that it is ineffective, and you want the compression to be pretty consistent so you maintain the same prop clearance after rebuilds.

Rune

Hi
I really dont know any about the stifness exept that its pretty hard , the rubber is 10x 10 mm and it has a bolt in one end and a hole with treads in the other.
I rember there where some rubber stiffnes grades when we use this to the 60 engines back in the 80-90's but this was some that my supplier off tools and bearings that we use in our business came up with.

bjr_93tz

Available in many sizes, styles and hardness from Element14 (formerly Farnell) for their usual extortionist pricing. I'm sure they'd be available from other sources with better prices.

http://www.farnell.com/datasheets/1286912.pdf

Interesting it was the Gator soft mount for the Hanno I first encountered these, years later when the internet came along I realised they aren't designed for use in tension, only compression and shear?? Never had (or heard) of any problems with them event though everyone in the pattern game uses them in tension (mostly)...

Rune

the way I have used them its compresion.