Re: [Amel] Re: Modifications


Malcolm Phillips <MPhillips@...>
 

Eric/Ian,



You may be interested to note that the bearing spec on my
Redline 464 gives 2 sealed ball races and one open, ie the top
one which then allows you to fill with oil. I am very
impressed with Ian,s modifications which I may do when I next
overhaul the bow thrusters gearbox. Unfortunately on the first
overhaul I concluded that the bevel gears were worn after
running in emulsion for a year SO PACKING WITH WATERPROOF
GREASE MAY BE THE ONLY WAY OF GETTING A SWEETER SOUND BACK !



Malcolm



S/M 464 Bon Jovi



From: amelyachtowners@...
[mailto:amelyachtowners@...] On Behalf Of kimberlite
Sent: 03 July 2010 06:13
To: amelyachtowners@...
Subject: RE: [Amel] Re: Modifications





Ian,

As I understand what you wrote about the bow thruster you added a sleeve
in
the shaft that is connected to the prp and replaced the bearings with
sealed
bearings and then packed the gearbox with grease.

Why can you not add oil from the top of the bow thruster?

Fair Winds

Eric

Amel Super Maramu #376 Kimberlite

_____

From: amelyachtowners@...
<mailto:amelyachtowners%40yahoogroups.com>
[mailto:amelyachtowners@...
<mailto:amelyachtowners%40yahoogroups.com> ] On Behalf Of sv_crusader
Sent: Saturday, July 03, 2010 12:56 AM
To: amelyachtowners@...
<mailto:amelyachtowners%40yahoogroups.com>
Subject: [Amel] Re: Modifications

Hello Richard,

the stainless bush was an exact copy of the bronze one, except that it
was
made with three grub screws instead of two to allow better centering.

Assembled with grease there are no signs of any Galling after over three
years of use. In fact both the shaft and the bush look as new.

I am off for 10 weeks sailing this morning, so will be unable to reply
further until I find a wireless network to log on to, but I will be glad
to
discuss further when I get back.

Regards

Ian SM414 Crusader (Headed for Mersin Eastern Turkey)

--- In amelyachtowners@...
<mailto:amelyachtowners%40yahoogroups.com>
<mailto:amelyachtowners%40yahoogroups.com> , Richard03801
<richard03801@...>
wrote:

Thanks for the info. One question how much clearance did you plan
between
the shaft and bushings? Metal to metal ss to ss normally does not work
well.
If they touch they will Gaul as the bronze is used as a bearing surface.
It
may be that the bearing pack is stiff enough to hold the shaft from
moving/touching. I guess time will tell.
Regards
Sent by Richard Piller

On Jul 1, 2010, at 5:55 PM, Ian Shepherd <sv_freespirit@...> wrote:

I read recently that owners modifications can be detrimental to the
original concept. Maybe so, but here are three modifications that
have
definitely improved my boat.

Three and a half years ago I replaced the bronze main engine prop
shaft
bush with one made of high grade stainless steel. I recently hauled
for
the first time since fitting it and there was absolutely no wear
whatsoever on the bush. Just a very slight polishing of the surface
where the lip seals mate to the bush. There was no noticeable wear
to
the seals either after 600 hours of motoring, but I changed them
anyway.

This contrasts markedly to the normal wear experienced on the
standard
bush. I believe that the maintenance interval is now much longer
with
the stainless bush, and there is a worthwhile long term cost saving
too.

I replaced the 70M of chain supplied by Amel with 90M. There was a
noticeable improvement in the boats motion particularly in short
seas.
The boat pitches less, hardly ever slams any more and because of
this
maintains a higher average speed. I also have 10M of chain and 100M
of
rope for my second anchor stored in the forward locker together with
my
two Fortress anchors, so in reality, I have the equivalent of 100M
of
10mm chain in bow. The extra weight forward certainly seems to be
for
the better.

I decided to try and improve the lubrication of the bow thruster,
which
seems to have more sea water inside it than oil most of the time.
The
arrangement of a single lip seal over a rough fibre shaft is hardly
conducive to keeping the sea water out. I removed the shaft and had
it
machined down to accept a thin stainless sleeve for the lip seal to
run
on. I then replaced the three open ball race bearings, which were
all
rusty, with sealed bearings running in their own grease. Of course
this
prevents you pouring the oil in via the top of the tube, so I
decided to

not use oil to lubricate the bevel gears, but instead use water
repellent grease.

This was packed into the gearbox housing before the back plate was
refitted, leaving a small gap to allow for expansion, and grease was
also placed between the outside of the outer bearing and the lip
seal.
This was done about four months ago, and the bow thruster has never
sounded sweeter. Gone is the awful sound of bearings running is a
sea
water emulsion, and there does not seem to be any loss in power
either.
Time will tell, and I shall remove the bow thruster this winter to
see
if the modifications have had any adverse effects on the gears, but
it
is my guess that the life of the seal, bearings and bevel gears will
be
considerably increased.

As they say, cruising is fixing things on water. Anything that
reduces
wear and subsequent failure must be for the better.

Ian Shepherd SM 414 Crusader






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