Re: [electricboats] One engine down...looking for solutions/suggestions

I don't know anything about your controller, but some (many?) do have programmable throttle response profiles & types.  I know that mine (an ALLTRAX AXE4836 DC mtr controller) can be set to use an S-profile or something like that that provides lowpass filtering on the throttle to eliminate sudden jerks.  I should change mine to use that response (I have an old outboard motor)---with a shear pin driving the prop, if I suddenly shove it into reverse or forward or suddenly 'gas it', bye-bye shear pin and the boat is suddenly a row boat.  Usually that happens at the worst times too.

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of fred jelich
Sent: Thursday, May 6, 2021 8:03 PM
To: electricboats@groups.io
Subject: Re: [electricboats] One engine down...looking for solutions/suggestions

 

So, my question now :

Can the electric motor torque (rough) be tamed by the motor controller, just by programming (torque min/max, by the amps applied to it) , to make a "smooth shift" from forward to reverse, so I don't crash my saildrive's internal gear ?

 

 

On  my Kelly controller, when I go from reverse to forward, it slows down gradually, then slowly ramps back up.

 

On Thu, May 6, 2021, 9:58 AM Carsten via groups.io <Carstensemail=yahoo.com@groups.io> wrote:

Well, I see your point, Steven. Same as my concern.

 

Diesels are damned slow in everything, as they just are, well, diesels.

So you need to slow it down, put the gear in neutral, and then engage reverse.

So, not much stress to any of the gears.

 

Using an electric motor it is a beast to be tamed, compared to the diesel, because it has the power from outside, readily avaiable at all times. Cold or hot, no start-up needed. Just GO. One way or the other. Doesn't matter.

 

So, my question now :

Can the electric motor torque (rough) be tamed by the motor controller, just by programming (torque min/max, by the amps applied to it) , to make a "smooth shift" from forward to reverse, so I don't crash my saildrive's internal gear ?

 

I'm a ME, not an EE.

But, still trying to learn everything what's going with those funny electrons...

 

All qualified, please comment on this.

 

 

 

On Thursday, 6 May 2021, 22:16:59 GMT+8, Steven Chmura <chmura.steve@gmail.com> wrote:

 

 

I'm looking at doing the same conversion. I have the 120s with a couple tired VP D2-40s. My concern was the increased immediate load vs the ramped up torque via the ICE. Would love to get it installed by end of year!

 

On Thu, May 6, 2021 at 9:32 AM Carsten via groups.io <Carstensemail=yahoo.com@groups.io> wrote:

Seems that saildrive conversions is a recurrent issue here.

Have any of you ever made a conversion to electric on a saildrive ?

 

I would like a direct driven solution too.

But I need an electro motor optimized for 1600-2200 RPM. Not 5000.

Do any of you know a supplier who can deliver such low rev (optimized) motors ?

Do we have to go to China for this, or are there still qualified suppliers in the West ?

 

For power rating, my Volvo Penta 100S saildrive is supposed to be supporting a 24 HP diesel.

But the torque, and the torque forces when changing direction (eg. from full forward to full backward) might not be a good cup of tea for the small gear wheels of the lower part, as electric powered motors has so much more torque power.

 

Please comment :-)

 

 

 

On Tuesday, 4 May 2021, 21:20:25 GMT+8, Timdownes61@gmail.com <timdownes61@gmail.com> wrote:

 

 

Hi Flip

I have a similar issue one of my 2002 engines is 35 years old and not got a bright future, rather than a rebuild, an electric motor fitted to the S120C saildrive is my preferred option.  Have you considered using the rear gearbox mount only or building a frame to utilize the 2 diesel mounts as well to handle the lateral force from the rotating prop?

I will be watching your progress with interest. Motor direct coupled to vertical shaft is intriguing

Tim
33ft Imp Catamaran