Python drive v Aquadrive

**Roach1948** · 22-10-07, 13:31

I have done the same with a BETA 13.5
As you see here the thrust bulkhead is designed to take the thrust onto the new bearers under the engine. The bearers themselves being beefed up to cross several floor frames, so no part of the hull has undue stress on it. All in all I am very happy with my AquaDrive and it helps my old wooden yacht shaking itself apart.

**thalassa** · 22-10-07, 19:39

Vyv and Roach1948, thank you for the pictures. Haven't got a photo, but in my situation the engine bed as well as the sides were too far off, so it became a mild steel H- form. Did you treat the steel before glassing it up?

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I am very happy with my AquaDrive and it helps my old wooden yacht shaking itself apart.

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Sorry for my limited command of English, but ...? [img]/forums/images/graemlins/shocked.gif[/img]

**Steve_N** · 22-10-07, 20:31

And of course you can mount the Aquadrive vertically also, if this fits better in your boat. My shaft runs a long way up from the hull, plus the exhaust was in the way, so it needed some complicated steel brackets:

The upper part of the bracket which braces the structure forward to the existing bulkhead isn't yet fitted in that picture, but you can see it emerging into the engine compartment here:

**oldsaltoz** · 22-10-07, 22:51

G'day Gunfleet.

<<<how to fillet in a support/thrust plate for one of these. Halyard/Aquadrive are rather reticent about offering advice for this part of the installation on a grp boat>>>

Installing a thrust plate for the above would be very dependant on the type of hull and existing fit out, so no "one fits all" instructions available.

No doubt this is why the manufacturers are a bit coy about advising what is required.

Possible method may be based on:

I suspect I would opt for a substantial stainless steel mounting plate around 12 to 20mm with gussets each side, welded to an under plate then a cross strip frame all bedded on Micro fibres and glassed over with 8 layers of 200 gram cloth and epoxy resin, each sheet being around 2 inches larger than the first to spread the lead and allow some flexing away from the base plate' Then add a final layer of 150 gram roving's with 3 coats of resin and one coat of pigmented resin to give a very smooth and easy to clean base.

If you are contemplating the above installation I could e-mail a conceptual drawing based on some more information and perhaps a picture or two.

Don't be in a hurry though as I have two projects underway at the moment, 10 units (flats) with full floors to be fibreglassed and a power cat transom outboard pod and rear cockpit modifications to complete.

Avagoodweekend.......

**Gunfleet** · 22-10-07, 23:18

Hi Oldsalt
That's a substantial solution. I'm going to do the job at the end of January (hence my interest). My cutlass and shaft sound knackered and I think while I'm at it I might as well go for a full monty solution with an Aquadrive. I may well take some pictures and ask you again after Christmas. Glad to see you've forgiven us for the rugby.

**srp** · 23-10-07, 08:34

It'll probably be worth you talking to Halyard at the London boat show - they usually offer hefty discounts for orders taken during the show. I got mine for around £100 less than list price.

**vyv_cox** · 23-10-07, 09:50

The only treatment I carried out on the steel was to grind the outer inch or so to give the resin a good key. It has been installed for five years or so and I inspect it now and then. No sign of cracks or disbonding so all seems well.

On the plate thickness - my original plan was to use heavier metal, in stainless steel, The people who cut the steel for me had done a number of Aquadrive installations in fishing boats and said that 6 mm was the thickest they ever used. They didn't use stainless steel even though it would seem a better choice, so I went along with them.

**Roach1948** · 23-10-07, 10:40

[ QUOTE ]
Did you treat the steel before glassing it up?[ QUOTE ]

Obviously mine is not glassed up, but bolted in place. It is made from mild steel and then hot dipped galvanised.

-- What I meant was that there is very little vibration now that I have installed the aquadrive.

**martinriches** · 23-10-07, 20:08

I spoke to Halyard at SIBS they suggested 18mm ext.ply with fore and aft fillets.

I notice on the Python drive website they say it mustn't be installed inline ie needs a angle to it. which would be no good for my boat. Doesn't say any thing about the Aquadrive needing that. Anybody installed it inline? Or maybe I am misreading the info.

Martin

**pvb** · 23-10-07, 20:23

The Python Drive caution against inline installation says that this results in poor lubrication of the CV joints. Logically, exactly the same problem would occur with the Aquadrive.