Furler motor to gearbox sm2000


Mike Ondra
 

Picking up on a thread from last year re shearing of the motor shafts on the furling motors between the motor and gear box.  Happened to SV Delos as shown in Episode 317 around the 10 min. mark. Others have experienced this, all at the same place (Nebo sm251, Aletes SM 240 twice, and I believe Delos is in the 250’s or 260’s). Curious if others have experienced this and if anyone has an explanation. This is a fairly stout shaft and it would seem the motor should stall before shearing if the shaft was healthy (no fatigued). There is no shaft exposure to weather.

 

Mike Ondra

Aleses SM#240

Chesapeake Bay, USA


Brent Cameron
 

Hi Mike.  Delos is Hull #303.  

Brent

On May 3, 2021, 9:11 PM -0400, Mike Ondra via groups.io <mdondra@...>, wrote:

Picking up on a thread from last year re shearing of the motor shafts on the furling motors between the motor and gear box.  Happened to SV Delos as shown in Episode 317 around the 10 min. mark. Others have experienced this, all at the same place (Nebo sm251, Aletes SM 240 twice, and I believe Delos is in the 250’s or 260’s). Curious if others have experienced this and if anyone has an explanation. This is a fairly stout shaft and it would seem the motor should stall before shearing if the shaft was healthy (no fatigued). There is no shaft exposure to weather.

 

Mike Ondra

Aleses SM#240

Chesapeake Bay, USA


--
Brent Cameron

Future Amel Owner & Amel Owner Registry Moderator

Oro-Medonte, Ontario, Canada


eric freedman
 

Hi Mike,

What furling motor is this? Main or Genoa?

Fair Winds

Eric

sm

 

From: main@AmelYachtOwners.groups.io On Behalf Of Mike Ondra via groups.io
Sent: Monday, May 03, 2021 9:11 PM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] Furler motor to gearbox sm2000

 

Picking up on a thread from last year re shearing of the motor shafts on the furling motors between the motor and gear box.  Happened to SV Delos as shown in Episode 317 around the 10 min. mark. Others have experienced this, all at the same place (Nebo sm251, Aletes SM 240 twice, and I believe Delos is in the 250’s or 260’s). Curious if others have experienced this and if anyone has an explanation. This is a fairly stout shaft and it would seem the motor should stall before shearing if the shaft was healthy (no fatigued). There is no shaft exposure to weather.

 

Mike Ondra

Aleses SM#240

Chesapeake Bay, USA


Mike Ondra
 

Eric,
We had both the outhaul and furling motor for the main shear several years ago.
Mike


On May 3, 2021, at 11:01 PM, eric freedman <kimberlite@...> wrote:



Hi Mike,

What furling motor is this? Main or Genoa?

Fair Winds

Eric

sm

 

From: main@AmelYachtOwners.groups.io On Behalf Of Mike Ondra via groups.io
Sent: Monday, May 03, 2021 9:11 PM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] Furler motor to gearbox sm2000

 

Picking up on a thread from last year re shearing of the motor shafts on the furling motors between the motor and gear box.  Happened to SV Delos as shown in Episode 317 around the 10 min. mark. Others have experienced this, all at the same place (Nebo sm251, Aletes SM 240 twice, and I believe Delos is in the 250’s or 260’s). Curious if others have experienced this and if anyone has an explanation. This is a fairly stout shaft and it would seem the motor should stall before shearing if the shaft was healthy (no fatigued). There is no shaft exposure to weather.

 

Mike Ondra

Aleses SM#240

Chesapeake Bay, USA


michael winand
 

Hi Mike,  mine sheared when I was unfurling the sail.  Still confused about how this was possible.  I replaced the gearbox and motor with the Bongifoly.  See if it works for as long. 
Amel used these on the earlier versions of the SM 
Michael  Nebo  sm251 


On Tue, 4 May 2021 at 7:57 pm, Mike Ondra via groups.io
<mdondra@...> wrote:
Eric,
We had both the outhaul and furling motor for the main shear several years ago.
Mike


On May 3, 2021, at 11:01 PM, eric freedman <kimberlite@...> wrote:



Hi Mike,

What furling motor is this? Main or Genoa?

Fair Winds

Eric

sm

 

From: main@AmelYachtOwners.groups.io On Behalf Of Mike Ondra via groups.io
Sent: Monday, May 03, 2021 9:11 PM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] Furler motor to gearbox sm2000

 

Picking up on a thread from last year re shearing of the motor shafts on the furling motors between the motor and gear box.  Happened to SV Delos as shown in Episode 317 around the 10 min. mark. Others have experienced this, all at the same place (Nebo sm251, Aletes SM 240 twice, and I believe Delos is in the 250’s or 260’s). Curious if others have experienced this and if anyone has an explanation. This is a fairly stout shaft and it would seem the motor should stall before shearing if the shaft was healthy (no fatigued). There is no shaft exposure to weather.

 

Mike Ondra

Aleses SM#240

Chesapeake Bay, USA


Matt & Michelle Day, SM#208 SV Talia
 

Most electric motors use mild steel shafts (I doubt the electric motors on the AMEL have nickel or nickel-vanadium shafts due to cost).  The shafts are designed for an infinite life in a controlled environment, given the design torque of the motor/stator.  We have all seen how mild steel can corrode in sodium rich environment.  The pitting that can occur from the sodium ingression can limit the design life at the design torque due to stress corrosion cracking.  


Bill Kinney
 

I think "stress corrosion cracking" is a red herring here.  While carbon steel certainly can corrode rapidly in salt water, the chemistry just is not the same as with stainless alloys that stress crack in the presence of chloride.  If there was enough salt water bouncing around in the motor housing to seriously corrode the shaft, I would expect LOTS of other issues to go south first!  This would be easy to confirm with a look at a sheared-off shaft.  (Anybody have a photo?)

In normal operation the motor simply can not develop enough torque to shear off the shaft.  I have certainly stalled the outhaul motor many times while flattening the sail without a mechanical failure. While it might be possible that there was an epidemic of bad steel bar stock for motor shafts, this seems very unlikely.  

I have never done a post-mortem on one of these that has failed, so all this is a guess... There are two possibilities I see, both related to wear in the gear box.  

A worn or broken bearing could allow enough runout of the worm screw that it imparts a significant side loading on the motor shaft.  This could result in a failure of the kind seen.  I think this is the most likely cause.

Another possibility is either by wear of the gear teeth, or a bearing failure, the worm suddenly jams in the gear while running at speed.  I can imagine this kind of shock loading causing a shear failure. I don't see this happening by an external load, the 60:1 gear ratio would just not transmit enough of a shock load back to the motor--but you never know...

Again, all just SWAG (Scientific Wild Ass Guessing) without having a failed unit in hand.

It also appears incorrect to say that older boats had Bonfiglioli and new ones had Leroy-Somers drive trains (or vice versa).  Amel seems to have switched back and forth during the production run.  Our boat (#160) has Leroy-Somers, and I have seen higher hull numbers with either supplier.

Bill Kinney
SM160, Harmonie
Hollywood, FL


Matt & Michelle Day, SM#208 SV Talia
 

When I pulled the outhaul motor and gearbox off of Talia back in Feb (before I pitched myself from the mizzen mast), the shaft was sheared before the first shaft step behind the keyway.  You can see the stress rings on the shear plane of the shaft.  They start at a single point.  I could not tell if it was corrosion, or an inclusion without polishing.  However, an inclusion on the surface of the shaft would be very odd.  I still have the motor and shaft, and will pass along a few pictures when I can get back to the boat in June.  I will see if I can polish the shear surface as well for fun.

Not sure I buy the wear on the gear teeth and side loading with a bonze tooth gearbox.  I fully expected to see wear on the teeth, following BWs book.  There was little to no wear presence and the tooth convolutes were clean and mirror like when washed down. 

I also can't reason AMEL designing a drivetrain where the gearbox is the failure mechanism .  No self respecting Mech Eng would do that.  Your coupling/keyway should fail first, followed by your easily changed electric motor.  I think AMEL has done a fine job designing this geartrain, and Gary did a great maintaining the boat prior to my owning it.  But, on this specific boat the motor shaft red herring failed.   


Alan Leslie
 

With all due respect, Amel didn't "design" the gear train, they only specified it.
Both the Leroy Somer and Bongifoli(?) units are standard production industrial motor gearbox units used in factories for example as conveyor drivers.
They are nothing special.
And there are plenty of alternatives out there.

Cheers 
Alan
Elyse SM437
On my way to New Zealand today to be reunited with my beautiful boat after more than a year !


Germain Jean-Pierre
 

Hey Alan, 

Good for you!

Other than a long beard, the batteries are ok, the water tank should have water. 

We are doing a maintenance cycle and will be on G17 tomorrow AM. 

JP


On 14/05/2021, at 10:21 AM, Alan Leslie <s.v.elyse@...> wrote:

With all due respect, Amel didn't "design" the gear train, they only specified it.
Both the Leroy Somer and Bongifoli(?) units are standard production industrial motor gearbox units used in factories for example as conveyor drivers.
They are nothing special.
And there are plenty of alternatives out there.

Cheers 
Alan
Elyse SM437
On my way to New Zealand today to be reunited with my beautiful boat after more than a year !


Heinz Stutenbaeumer
 

Dear Alan 
My Amel is also in New Sealand. 
Did the New Sealanders let you in? Iff so how did you do that? Can you write me an Mail please 
heinz@...
Thanks 
Heinz SM 2000, 292, SY Quetzal.



Am 14.05.2021 um 00:21 schrieb Alan Leslie <s.v.elyse@...>:

With all due respect, Amel didn't "design" the gear train, they only specified it.
Both the Leroy Somer and Bongifoli(?) units are standard production industrial motor gearbox units used in factories for example as conveyor drivers.
They are nothing special.
And there are plenty of alternatives out there.

Cheers 
Alan
Elyse SM437
On my way to New Zealand today to be reunited with my beautiful boat after more than a year !


Alan "Woody" Wood
 

Hi Michael

Having spend €500 getting the casing for our Leroy Somer rebuilt I'm now trying to source new brushes in the Caribbean.. which isn't easy for an obsolete motor :/
I now wish I'd just replaced it when it seised in the first place.

Can I ask what model number of the Bongifoli you replaced the LS with?.. do you have a link to it?

Cheers
Woody


michael winand
 

Hi Woody,
These are the numbers of the motor  and gearbox.  You will have to have new cedal holders made to mount the gearbox to the mast,  also the shaft that engaged the mast furling is a different diameter,  you can machine the gearbox to suit the shaft on the outhaul and the mast (easy enough to do), I had a new post that fits the mast furling made instead of changing the gearbox, 
The ratios is a little slower not really an issue, 
MVF044070063PB14
MVF44P R70 F63 B14

NPN61
330W 24V  F63B14 LN56
NO FANNING IP54 
Motor and gearbox cost 900 aus dollars,  not sure what the cost of the machine shop is,  probably another 600. But that’s because they have the design drawings for the cnc machine to make them. New LS from Amel was 3000 aus 

Hopefully you can have your motor repaired. 
Michael 

14

On Sat, 15 May 2021 at 6:44 am, Alan "Woody" Wood
<woody@...> wrote:
Hi Michael

Having spend €500 getting the casing for our Leroy Somer rebuilt I'm now trying to source new brushes in the Caribbean.. which isn't easy for an obsolete motor :/
I now wish I'd just replaced it when it seised in the first place.

Can I ask what model number of the Bongifoli you replaced the LS with?.. do you have a link to it?

Cheers
Woody


Teun BAAS
 

Hi Alan,

 

I have the same question; can you cc me when you reply Heinz.

 

Best Regards Teun

SV AMELIT  A54  #128

 

I am in USA

AMELIT is in Storage on the hard in COOMERA (near BRISBANE) QLD AUSTRALIA

May 16, 2021 17:52:42

 

USA cell: +1 832 477 8842

AUSTRALIA cell: +61 5951 8909

 

You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT

 

 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Heinz Stutenbaeumer via groups.io
Sent: Friday, May 14, 2021 01:11
To: main@amelyachtowners.groups.io
Subject: Re: [AmelYachtOwners] Furler motor to gearbox sm2000

 

Dear Alan 

My Amel is also in New Sealand. 

Did the New Sealanders let you in? Iff so how did you do that? Can you write me an Mail please 

Thanks 

Heinz SM 2000, 292, SY Quetzal.

 



Am 14.05.2021 um 00:21 schrieb Alan Leslie <s.v.elyse@...>:

With all due respect, Amel didn't "design" the gear train, they only specified it.
Both the Leroy Somer and Bongifoli(?) units are standard production industrial motor gearbox units used in factories for example as conveyor drivers.
They are nothing special.
And there are plenty of alternatives out there.

Cheers 
Alan
Elyse SM437
On my way to New Zealand today to be reunited with my beautiful boat after more than a year !


Michael & Robyn
 

Hi Woody,

are you still seeking the motor brushes for the LS MBT86M motor?
I have ordered my "Brushes .31" x .39" x .7" BRUSH SPR-A007"
from
https://store.eurtonelectric.com/31x31x6brushspr-a005-1-1-1.aspx

I have  a few extra; We are in Christiansted St. Croix in Green Cay Marina, leaving Tuesday.
--
Michael & Robyn

SY RIPPLE SM2K # 417