Re: Mizzen furler gearbox, A54 peculiarity?


Sv Garulfo
 


Hi,

To close the thread:

I gave up on trying to unscrew the bottom. It was getting too risky to damage the unit and no one would be impressed with the drama. 

I think the only difference between the SM and the A54 (later hull numbers) gearboxes is 
1. the absence of top screwed lid on the A54 version,
2. The bottom lid holes are not drilled through on the 54. 

The rest is designed the same. I eventually managed to loosen the bottom part of the internal column. After much fresh water cleaning, the column rotates freely. 

I drilled the bottom lid holes through. They now act as drains like on the SM. I find that makes more sense. 

I cleaned the horizontal winch handle shaft and bushing. This is where the stiffness really comes from. I treated the aluminium/stainless steel interface with Tef-Gel.

I lightly greased the gears interface with marine grade grease. I left the Delrin balls alone and I’ll monitor how that evolves. 


Thanks all for your help,

Thomas 
A54-122
Tahuata, French Polynesia 






On Tue, 19 May 2020 at 08:29, Sv Garulfo via groups.io <svgarulfo=gmail.com@groups.io> wrote:
Hi Randall 

Thanks for that explanation

Do you remember if the internal column (vertical axis) is in 2 parts that are free to move  with respect to each other?

In mine, when the furler turns, the top part of the internal column (with the teeth) turns, but the bottom part does not (does not bulge at all). I’m puzzled as to whether that’s expected or not. The movement of the top part is smooth and feels normal. 
If I look at the drawing of the SM furler, I can’t see how the bottom part (part #9) would move so freely from the top part (part #6). 
image1.jpeg


Best,

Thomas
GARULFO 
A54-122
Tahuata, French Polynesia 


On Tue, 19 May 2020 at 04:27, Randall <sailingalbedo@...> wrote:
Thomas,
I have inverted the picture. My furler only opens from the bottom, it just appears too open at the top. I think it was just a different casting, but the unit is the same.
The bar with the 2 drill bits passed through was just a scrap 2 foot length,18 inches to 24 will work.
A good vise, with a good wrap of bendable metal to protect the furler from vise teeth. If you put the crank handle shaft back in, it will keep the furler from turning in the vise.
Turn bottom a turn or two, then remove the crank handle shaft.
When putting the bearings back in after cleaning (do not grease bearings) insert internal gear up just far enough to feed the top set of bearings ,then push up, turn over put bottom bearings in tighten bottom, install Crank handle shaft. I doubt the unit will need to be done again for a long time, But anti seize may be an idea??

Hope that helps.
Randall
A54 #56
Still in Gib...

On Tue, May 19, 2020 at 1:53 AM Sv Garulfo <svgarulfo@...> wrote:
Hi Randall & Mohammad,

In Randall’s picture, i noticed the gearbox housing is consistent with the drawing in Gary Silver’s document. 

My gearbox appears slightly different, at least from the outside. It doesn’t have a screwed top lid. 

Mohammad, 
what is your gearbox like? Mine or Randall’s? 
Does it have straight through drain holes?


Randall,
Did you have to apply great force to unscrew the bottom part? How much leverage does your tool have? How long is the handle?



Thanks

Thomas
A54-122
Tahuata, French Polynesia 



On Sat, 16 May 2020 at 02:13, Randall <sailingalbedo@...> wrote:
Thomas,

There were 2 sets of Delrin bearings 1st set just under the bottom cap and the other in the top. My furler took 2 hands and great force to turn.
Just like in the Delos video. If you look at the one picture you can see the place where the Delrin bushings in the cranking shaft with the gear, has eroded and that is where all of the stiffness is coming from.
I can only say that the 2 holes in my furler bottom go all the way through.
I intend to make a start to finish video of this. It was incredibly simple and now the furler moves like new.

Cheers,
Randall

On Fri, May 15, 2020 at 7:21 PM Sv Garulfo <svgarulfo@...> wrote:
Thanks Randall,

I will attempt to watch the video but I doubt the bandwidth here will allow that...

Further to Mohammad’s question, did you find a bearing inside or delrin balls like Gary described? 
As far as I can see through the horizontal shaft opening, there is a vertical element (consistent with the diagram in Gary’s document) that is supposed to be on a set of derlin balls at the bottom of the housing, but mine does not rotate at all. 

Clearly the gearing housing is not waterproof and without drains it will inevitably fill with dirt and water up to the attachment bolts. The bushing is then halfway soaked in that and the aluminium/stainless steel interface between the gearshaft and the winch handle socket attachment will corrode. The oxidation on the aluminium shaft will slowlly increase the friction to the bushing. The gears are moving freely otherwise. 

So, drill for drain or not? 


Thanks
Thomas

GARULFO 
A54-122
Tahuata, French Polynesia 




On Thu, 14 May 2020 at 10:11, Randall <sailingalbedo@...> wrote:
Thomas,
I removed disassembled and cleaned my mizzen outhaul last fall. You don't need to drop sail. The issue will be in the Delrin bushings that become very stiff. I have attached 2 pictures of my work. The bearings are not to be lubed/greased. I used a cheap homemade tool to unscrew the bottom. 2cm square bar 2 drill holes straight through, put the drill bits in so the solid end goes into the bottom of the furler, with furler in a vice. Worked great. 
I finished and put on a video from a fellow Amel owner who did the same job. https://www.youtube.com/watch?v=EB67b2hK-kA&t=657s
They do the job at 8.02 of the video. If you need more info let me know. Use the bar not the saw.
Cheers.
 
Randall
A54 #56
Gibraltar



On Wed, May 13, 2020 at 6:50 PM Sv Garulfo <svgarulfo@...> wrote:
Hi all,

In the great document by Gary Silver about the overhaul of the SM Mizzen furler gearbox (thanks Arno for sending us a low bandwidth friendly version), it is mentioned that the bottom part of the gearbox housing is drilled with 2 holes that are used to both unscrew that part (with great efforts) and drain the gearbox of liquids. 

As our gearbox got stiffer recently, I removed it and it appears that those 2 holes are not through openings.. thus not acting as drains. And the gearbox was full of rainwater up to the attachment bolts. Arno tells me he saw the same. 
So the teflon bushing got very dirty and stiff with all sorts of deposits. 

Does anybody know why the drains are no longer machined through? Is it an A54 “innovation”? 
It doesn’t really make sense and I’m thinking of drilling those holes all the way through to reinstate the drain. Any word of advice against that idea?

Thanks for your input

Best, 


Thomas
GARULFO 
A54-122
Tahuata, French Polynesia 


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