Message text written by Graeme Smith
>One of my first impressions of the Europa, way back in the earliest days
when G-YURO was the only one in existence, was that when the engine was
started, the spinner didn't spin, it wobbled. Now that I'm trying to fit
the spinner I can see why.
Most of the completed Europas that I've seen since have been at
Cranfield with their engines stopped so I don't know whether wobbly
spinners is still a general problem or not.
I have a VERY early Mk 1 kit (No 26), if any other early pioneers could
give me a hint on how to make the spinner run true I'd be very grateful.
<
The existing back and frontplate are the problem. There are alternatives
available for each.
Backplate - Graham Singleton makes a very nice carbon fibre backplate which
is much better than the original being both stiffer and better made. If my
memory serves me correctly it is also ready drilled for mounting to the
hub. To improve the stiffness further Graham gave it some curvature between
the centre and the rim. The only problem with this is if you intend to use
a VP prop with an electrical brush ring (eg. NSI VP prop) as the curvature
prevents the ring being fitted. I have found a solution to this should you
need it.
Frontplate - John Scott (PFA Inspector) has produced a very neat
alternative frontplate which is useable on the NSI VP prop. It may be
possible to adapt it to other props. Although it is still fibreglass it has
two advantages over the original. Firstly it is mounted further forward
giving much improved stability and secondly it is fixed permanently to the
spinner rather than the hub obviating the need for unsightly fixing screws.
It uses the body of the electric motor for location having a nylon sleeve
at its centre which is a push fit over the motor housing. Provided the
spinner is set true it should not put any significant load on the motor
housing and its main fixings are on the backplate as before.
When setting up the spinner, backplate and frontplate to the prop hub I
found that an old record player turntable was useful to ensure that
everything was set up true.
Although dynamic balancing may be expensive I intend to have it done as any
reduction in vibration reduces engine and airframe wear as well as reducing
risk of damage to avionics and instruments.
Nigel Charles
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