Forums, Engine, Gearbox, Stern Gear, etc, Centaflex v aquadrive coupling

Nick Howes at 13/01/2014 22:42:56
I am getting conflicting recommendations from different installers of beta engines, does anyone have experience of these couplings? Thanks, Nick

George Isted at 14/01/2014 12:09:17
Centaflex is clearly an easier install as no bonding in is required, however the thrust is still on the gearbox.

There is a new tech paper (yet to be uploaded to the site but I will email to you) that shows the use of a Centaflex.

Cheers

doug at 21/01/2014 15:59:59
I have a Centaflex coupling.
When I fitted a new engine it seemed to me that there was not enough room to install an Aquadrive. Given the space, I might well have gone for it.
The Centaflex is fine and I particularly like the collet fixing to the shaft which makes taking the shaft out simple. Lining up the engine is said to be less critical with this unit.
I can’t say I have noticed any great reduction in propshaft noise, and in this respect, the Aquadrive may be better.

PS
There is a little info in the Technical Paper: – Fitting a New Engine
Edited: doug on 2014-01-21 16:02:21

Keny at 23/01/2014 11:54:24
A lot will depend on which engine, mounts & propeller you intend to use as they all behave differently.
Could I ask DOUG which he used?
keny

moongirl at 23/01/2014 20:00:10
The Aquadrive gives a fixed distance from the connection to the prop. Whilst an excellent unit it does require a fixed element to be bonded in and you cannot do anything to the prop without removing the rudder.
Using a Centraflex if you need to do anything to the prop eg change to DARGLOW you can disconnect the shaft, pull the engine fwd and remove the prop without removing the rudder.
My own feeling is that the amount of ‘Shake’ on the engine mounts negates the advantages of the Centraflex.

Keny at 26/01/2014 09:28:55
Interesting angle. If you have an engine with big soft engine mounts that shakes about a lot perhaps all the propeller shock will be taken on the mounts. In which case neither system would be needed.In fact I could see the Aquadrive making it worse because it transfers the thrust onto 2 small bushes. keny

moongirl at 27/01/2014 19:47:56
Looking @ the Aquadrive diagrams it would seem that the bearer needs to be exactly at 90 degrees to the Prop shaft in both the vertical & horizontal such that there is no wobble – unless this is set up correctly there will still be eccentric wear on the shaft bearing. It seems that the CV Joints + Soft Engine Mounts allow for Engine movement.
How one sets up the bearer I am not sure. I guess I would use a short length of shaft to find the centre but measuring the angle and establishing the position of the bearer would be difficult given the lack of space – perhaps the Centraflex would be best after all!

Nick Howes at 28/01/2014 12:40:05
Hi Colin, thank you for your careful consideration, I think this together with the cost differential leads me to the same conclusion, Centaflex it is!

Regards, Nick

Nick Howes at 28/01/2014 12:42:37
Doug thank you for the benefit of your experience, I will go with the same, everyone who has them seems happy !

regards,

Nick

moongirl at 28/01/2014 20:01:51
On balance when I was going to buy Monique (the Wreck) I would have gone down the Beta + Centraflex route. I think you have made the right choice.