PythonDrive CV Coupling?
 

I posted this to a number of groups as I'm sure it's of interest to all.

I'm looking to purchase a CV coupling to go between the engine and the prop
shaft.

The two contenders seem to be either an Aquadrive or a PythonDrive. The
PythonDrive is cheaper. Has anyone any experience with the PythonDrive.

Will it handle movement from a soft mounted engine in up/ down, side/ side
and fore/ aft directions.

My engine is currently coupled to the prop shaft with a R&D flexible shaft
coupling, this is basically a plastic plate that can flex slightly. Although
the setup works, it's a bit primitive. At certain throttle settings the
engine bounces about a bit and vibrations can be felt.

Any info will be appreciated.

Adrian Smith

PythonDrive CV Coupling?
 

Adrian Smith wrote:
I posted this to a number of groups as I'm sure it's of interest to all.

I'm looking to purchase a CV coupling to go between the engine and
the prop
shaft.

The two contenders seem to be either an Aquadrive or a PythonDrive.
snip

Been there, done that.

The AquaDrive works.

Lew

PythonDrive CV Coupling?
 

"Lew Hodgett" wrote in message
ink.net...
Adrian Smith wrote:
I posted this to a number of groups as I'm sure it's of interest to all.

I'm looking to purchase a CV coupling to go between the engine and
the prop
shaft.

The two contenders seem to be either an Aquadrive or a PythonDrive.
snip

Been there, done that.

The AquaDrive works.

Lew

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and vibration?

Adrian Smith

PythonDrive CV Coupling?
 

Adrian Smith wrote:
I posted this to a number of groups as I'm sure it's of interest to all.

I'm looking to purchase a CV coupling to go between the engine and the prop
shaft.

The two contenders seem to be either an Aquadrive or a PythonDrive. The
PythonDrive is cheaper. Has anyone any experience with the PythonDrive.

Will it handle movement from a soft mounted engine in up/ down, side/ side
and fore/ aft directions.

My engine is currently coupled to the prop shaft with a R&D flexible shaft
coupling, this is basically a plastic plate that can flex slightly. Although
the setup works, it's a bit primitive. At certain throttle settings the
engine bounces about a bit and vibrations can be felt.

Any info will be appreciated.

Adrian Smith

An alternative (cheaper) is the Centaflex coupling. I have had one of
these for 15 years now and it has proven very effective in reducing
both vibration and shaft wear. it allows much more misalignment
(especially laterally) than the R&D disc. It is also much easier to fit
than an Aquadrive. I could not fit an Aquadrive in my boat as there was
insufficient space between gearbox and stern tube. The Centaflex
coupling simply replaces the R&D with no modifications to shaft or
hull. See http://www.centa.info/download/centaflex-m/de-en.pdf or try
Google for a supplier. I think the starting price is around £100,
depending on shaft size/engine HP.

Good luck.

Martyn Wills

PythonDrive CV Coupling?
 

Adrian Smith wrote:

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and
vibration?

At the time AquaDrive was the only product available.

There was a MAJOR reduction in both sound and vibration levels, at least
20dB each, and quit snapping mounting bolts like they were pretzels.

Unless Python is at least 40% lower in cost, my choice is AquaDrive.

Even then, doubt I'd by it.

Lew

PythonDrive CV Coupling?-Update
 

Adrian Smith wrote:

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and
vibration?

Just noticed that you are probably in UK which may impact pricing.

Here in US, a complete AquaDrive package, including engine mounts and
adapters is probably less than $1,500 USD for most sail boat engines.

Lew

PythonDrive CV Coupling?
 

"Lew Hodgett" wrote in message
link.net...
Adrian Smith wrote:

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and
vibration?

At the time AquaDrive was the only product available.

There was a MAJOR reduction in both sound and vibration levels, at least
20dB each, and quit snapping mounting bolts like they were pretzels.

Unless Python is at least 40% lower in cost, my choice is AquaDrive.

Even then, doubt I'd by it.

Lew

Is that because you have heard bad things about the PythonDrive? or that the
AquaDrive is somehow superior?

Adrian Smith

PythonDrive CV Coupling?
 

I fitted a Centaflex AGM coupling - 2 rubber couplings and a 2.4mtr 5
inch diameter hollow shaft in between and it was considerably cheaper
than Aquadrive - but not sure about Python drive. Are not Aqua and
Python the same thing but Python is the US version??

PythonDrive CV Coupling?-Update
 

"Lew Hodgett" wrote in message
link.net...
Adrian Smith wrote:

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and
vibration?

Just noticed that you are probably in UK which may impact pricing.

Here in US, a complete AquaDrive package, including engine mounts and
adapters is probably less than $1,500 USD for most sail boat engines.

Lew


Don't suppose you can remember what model/size AquaDrive you have?

PythonDrive for my engine (2.25litre 48BHP@2800) is approx 600USD (converted
from GBP) Probably get one cheaper over there. For complete unit/ adapters
but not engine mounts.

From what I can see in the specs there is not much difference between an
AquaDrive and a PythonDrive.

Adrian Smith

PythonDrive CV Coupling?
 

Adrian Smith wrote:

Is that because you have heard bad things about the PythonDrive? or
that the
AquaDrive is somehow superior?


I know the AquaDrive works.

I have no interest in trying to reinvent the wheel, especially for a one
time purchase.

Lew

PythonDrive CV Coupling?
 

"CS" wrote in message
ups.com...
I fitted a Centaflex AGM coupling - 2 rubber couplings and a 2.4mtr 5
inch diameter hollow shaft in between and it was considerably cheaper
than Aquadrive - but not sure about Python drive. Are not Aqua and
Python the same thing but Python is the US version??


I considered the Centaflex but I would like to fit really soft engine mounts
so preferred a double CV coupling.

It appears to me that both the PythonDrive and the AquaDrive both utilize
double CV joints. AquaDrive has been around longer and is therefore well
known. Maybe this is the only reason it's more expensive.

Adrian Smith

PythonDrive CV Coupling?
 

I considered the Centaflex but I would like to fit really soft engine mounts
so preferred a double CV coupling.

Centaflex AGM is a double coupling - one at the gearbox flange and one
at the thrust bearing. CV joints in Aqua and Python are still metal to
metal - and transmit noise. "Really soft engine mounts" - mounts
should be calculated to the weight they have to support. My engine has
6 mounts and each were calculated to take account of the static weight
plus the dynamic weight increase and or decrease caused by the torque
of the engine. The rubber is still quite stiff. Really soft mounts
may not be designed for the weight and will just collapse/bottom out
and you will have a very healthy noise short from engine to bearer..

PythonDrive CV Coupling?
 

"CS" wrote in message
oups.com...

I considered the Centaflex but I would like to fit really soft engine
mounts
so preferred a double CV coupling.

Centaflex AGM is a double coupling - one at the gearbox flange and one
at the thrust bearing. CV joints in Aqua and Python are still metal to
metal - and transmit noise. "Really soft engine mounts" - mounts
should be calculated to the weight they have to support. My engine has
6 mounts and each were calculated to take account of the static weight
plus the dynamic weight increase and or decrease caused by the torque
of the engine. The rubber is still quite stiff. Really soft mounts
may not be designed for the weight and will just collapse/bottom out
and you will have a very healthy noise short from engine to bearer..


By 'really soft', I mean mounts that are obviously suitable for the engine
but allow more movement than can realistically be accommodated for by the
typical coupling to the propshaft via a R&D coupling.

What kind of coupling joint does the Centaflex use?

Adrian Smith

PythonDrive CV Coupling?
 

On Mon, 11 Sep 2006 18:46:45 GMT, "Adrian Smith" wrote:


"CS" wrote in message
roups.com...

I considered the Centaflex but I would like to fit really soft engine
mounts
so preferred a double CV coupling.

Centaflex AGM is a double coupling - one at the gearbox flange and one
at the thrust bearing. CV joints in Aqua and Python are still metal to
metal - and transmit noise. "Really soft engine mounts" - mounts
should be calculated to the weight they have to support. My engine has
6 mounts and each were calculated to take account of the static weight
plus the dynamic weight increase and or decrease caused by the torque
of the engine. The rubber is still quite stiff. Really soft mounts
may not be designed for the weight and will just collapse/bottom out
and you will have a very healthy noise short from engine to bearer..


By 'really soft', I mean mounts that are obviously suitable for the engine
but allow more movement than can realistically be accommodated for by the
typical coupling to the propshaft via a R&D coupling.

What kind of coupling joint does the Centaflex use?

Adrian Smith

See note from Colin Stone (CS) who wrote
I fitted a Centaflex AGM coupling - 2 rubber couplings and a 2.4mtr 5
inch diameter hollow shaft in between and it was considerably cheaper
than Aquadrive - but not sure about Python drive. Are not Aqua and
Python the same thing but Python is the US version??

His installation is a little different to yours in that he has the
"doughnuts" 2.4m apart.
I fitted an AGM on my Narrowboat because
1 It was shorter than the Aquadrive or Python
2 No metal to metal and lubrication issues
3 Even though shorter the allowable angular misalignment appeared
greater
4 I got it cheap!

I had to move the engine forward 4 inches but fabricated some solid
mounts for the thrust bearing and I have been very pleased with it.
Very little to go wrong and thrust bearing (if it ever goes pop) is an
off the shelf item at most good bearing suppliers.

Richard

Nb "Pound Eater" Parkend G+S

PythonDrive CV Coupling?-Update
 

"Adrian Smith" wrote in message
.uk...
"Lew Hodgett" wrote in message
link.net...
Adrian Smith wrote:

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and
vibration?

Just noticed that you are probably in UK which may impact pricing.

Here in US, a complete AquaDrive package, including engine mounts
and
adapters is probably less than $1,500 USD for most sail boat
engines.

Lew


Don't suppose you can remember what model/size AquaDrive you have?

PythonDrive for my engine (2.25litre 48BHP@2800) is approx 600USD
(converted
from GBP) Probably get one cheaper over there. For complete unit/
adapters
but not engine mounts.

From what I can see in the specs there is not much difference
between an
AquaDrive and a PythonDrive.

Adrian Smith

Adrian
Everybody has been giving their own personal recommendations before
you said what engine you have in your boat and what sort of boat it
is.
Also, do you really want to mount the engine on flexible mounts rather
than solid mountings?
From your latest post, am I correct in assuming that you have a 4 cyl
diesel? Japanese based unit or BMC etc?

Are you more concerned about alignment problems or
vibration/noise transmission?

Phil

PythonDrive CV Coupling?-Update
 

Adrian Smith wrote:


Don't suppose you can remember what model/size AquaDrive you have?

From memory, up to about 30HP, they only have one unit.

The mounts are selected based on weight of engine/tranny.

They are soft enough to go into resonance at a low enough frequency to
isolate the engine vibration which is exactly why the system works so
well.

Lew

PythonDrive CV Coupling?-Update
 

Subject

Just for funzies, did a Google for "python drive".

Came up with several hits for web sites; however, many of them came up
empty.

I wonder why?

Lew

PythonDrive CV Coupling?-Update
 

"Phil R" wrote in message
...

"Adrian Smith" wrote in message
.uk...
"Lew Hodgett" wrote in message
link.net...
Adrian Smith wrote:

Why did you choose the Aquadrive over the cheaper PythonDrive?

Did you notice a big before/ after difference in both noise and
vibration?

Just noticed that you are probably in UK which may impact pricing.

Here in US, a complete AquaDrive package, including engine mounts
and
adapters is probably less than $1,500 USD for most sail boat
engines.

Lew


Don't suppose you can remember what model/size AquaDrive you have?

PythonDrive for my engine (2.25litre 48BHP@2800) is approx 600USD
(converted
from GBP) Probably get one cheaper over there. For complete unit/
adapters
but not engine mounts.

From what I can see in the specs there is not much difference
between an
AquaDrive and a PythonDrive.

Adrian Smith

Adrian
Everybody has been giving their own personal recommendations before
you said what engine you have in your boat and what sort of boat it
is.
Also, do you really want to mount the engine on flexible mounts rather
than solid mountings?
From your latest post, am I correct in assuming that you have a 4 cyl
diesel? Japanese based unit or BMC etc?

Are you more concerned about alignment problems or
vibration/noise transmission?

Phil



The engine is an Izuzu marine engine. (4 cyl)

I want to reduce all noise and vibration to an absolute minimum and that is
not possible on solid mounts. Some guys have solid mounts but they generally
have older, heavier low reving engines.

Adrian Smith

PythonDrive CV Coupling?-Update
 

"Lew Hodgett" wrote in message
ink.net...
Subject

Just for funzies, did a Google for "python drive".

Came up with several hits for web sites; however, many of them came up
empty.

I wonder why?

Lew

I have done the same and was surprised to only find one account of fitting a
PythonDrive. The author gave the thumbs up for the drive.

Adrian Smith

PythonDrive CV Coupling?
 

"Adrian Smith" wrote in message
. uk...
I posted this to a number of groups as I'm sure it's of interest to all.

I'm looking to purchase a CV coupling to go between the engine and the
prop shaft.

The two contenders seem to be either an Aquadrive or a PythonDrive. The
PythonDrive is cheaper. Has anyone any experience with the PythonDrive.

Will it handle movement from a soft mounted engine in up/ down, side/ side
and fore/ aft directions.

My engine is currently coupled to the prop shaft with a R&D flexible shaft
coupling, this is basically a plastic plate that can flex slightly.
Although the setup works, it's a bit primitive. At certain throttle
settings the engine bounces about a bit and vibrations can be felt.

Any info will be appreciated.

Adrian Smith



Guys, thanks for all your help.

I'll post here with what I decide to do and the results for others to
benefit from.

Adrian Smith

PythonDrive CV Coupling?
 

What kind of coupling joint does the Centaflex use?

Here are 2 pics
http://www.luxe-motor-kei.co.uk/inte...e/image47.html
http://www.luxe-motor-kei.co.uk/inte...e/image48.html

PythonDrive CV Coupling?
 

Adrian Smith wrote:

"Adrian Smith" wrote in message
. uk...

I posted this to a number of groups as I'm sure it's of interest to all.

I'm looking to purchase a CV coupling to go between the engine and the
prop shaft.

The two contenders seem to be either an Aquadrive or a PythonDrive. The
PythonDrive is cheaper. Has anyone any experience with the PythonDrive.

Will it handle movement from a soft mounted engine in up/ down, side/ side
and fore/ aft directions.

My engine is currently coupled to the prop shaft with a R&D flexible shaft
coupling, this is basically a plastic plate that can flex slightly.
Although the setup works, it's a bit primitive. At certain throttle
settings the engine bounces about a bit and vibrations can be felt.

Any info will be appreciated.

Adrian Smith




Guys, thanks for all your help.

I'll post here with what I decide to do and the results for others to
benefit from.

Adrian Smith



US prices range from $900 to 9500.

See US distributor:

http://www.pyiinc.com/index.php?acti...section=python

I was planning to go that route, but thanks to this thread I'm pretty sure I'll
go with Centra.

Brian C (for direct reply add an ell after the c)

PythonDrive CV Coupling?
 

"CS" wrote in message
ups.com...

What kind of coupling joint does the Centaflex use?

Here are 2 pics
http://www.luxe-motor-kei.co.uk/inte...e/image47.html
http://www.luxe-motor-kei.co.uk/inte...e/image48.html


I had overlooked the fact that you have a relatively long shaft between two
Centaflex couplings. If my engine was further away from the stern I would be
tempted to do the same.

After much thought I am going to fit the PythonDrive P60K 372GBP.

Thanks for supplying the pics, I read your website with great interest:-)

Adrian Smith

PythonDrive CV Coupling?
 

On 12 Sep 2006 13:55:19 -0700, "CS" wrote:


What kind of coupling joint does the Centaflex use?

Here are 2 pics
http://www.luxe-motor-kei.co.uk/inte...e/image47.html
http://www.luxe-motor-kei.co.uk/inte...e/image48.html


Holy cow!

Brian Whatcott Altus OK