Wednesday, September 2, 2020

Re: [electricboats] No Vibration? - How did you get there?

Mine was pretty close to this description.  I haven't gone on any trips yet but it's relatively quiet except for the sound of the spinning shaft through the hull and cutlass.  I have not noticed any vibration type noise.  I'm also using the Tstruck reduction with chain coupler and have greased the chain.


On Sep 2, 2020, at 7:15 PM, Lee Chrystal <lee@marshspecialtyhvac.com> wrote:



Lots of us are refitting older boats, aside from the electric motor itself noises and vibration will most certainly come from

Worn Cutless bearings. (Vibration)

Shaft misalignment.    (Vibration and certainly chain coupler noise, early parts retirement)

Bent, Worn out shaft.  (Causing worn Cutless bearing, Noisy coupler, Early parts retirement)

Bent props.                     ( all the above).

 

IMHO before installing your kit pull the shaft so you can inspect the surface where the Cutless bearing has been in contact with the shaft.

I could tell my Cutless bearing was worn before I even removed it by jiggling the shaft at the prop, I could move the shaft up and down a bit. Its when I pulled the shaft I found the shaft worn where the bearing contacts it.  I know a guy and had my shaft built up and polished and luckily it wasn't bent.

 

On a 1978 Balboa sailboat as I have I am glad I went through all the final drive components first as I found the issues described above… and if you had to change the Cutless bearing later it will change the alignment again slightly and you will likely get a little noise and vibration all over again, Crap…

 

Put the shaft in with the new parts including new shaft packing in the nut but don't screw on the packing nut yet.

 

You now will know where the shaft will be.

 

Then mount only the reduction plate with the lower pulley and the supplied shaft attached (Like it came out of the box from T-Struck) so it will be easier to play with the angle.

 

The two angles that bolt to the adaptor plate and connect to the engine rails could have a ¼ inch rubber pad under them, Reducing vibration through the hull. I have taken this approach.

 

The reduction plate has a variety of holes to get the system to the elevation you need for your specific boat and when I found which pre drilled holes I needed to use I bolted the angles on with SS Bolts ,Washers and Locknuts and then tig welded a few spots between the reduction plate and the angle to keep them from moving.

 

ALWAYS drill the correct size holes for the bolts so you reduce potential movement over time of any attached component. Smaller bolts than holes are bad!

 

You will now be able to make smaller slight adjustments up/down by compressing the rubber after you get it lined up as best as you can with as few shims as possible (Good rubber not a stack of old soft rubber bike tubes).

 

I used SS bolts washers and locknuts throughout the install when applicable anyway and now wont loose sleep over components ever becoming separated.

 

At the same time that you set your two braces to hold the reduction plate in place at the correct angle you need to line up the shafts without the chain coupler in the way so you can verify exact alignment with a straightedge, like a T-Square or metal rule. Top, Bottom, Side to side.

When you get it perfect as can be, and don't settle for not perfect just slide the shaft out a bit and install the coupler.

 

At this point i was able to spin the system with one hand and have it continue spinning a little bit (Inertia) so I feel its aligned nicely.

 

Now set your packing nut, install the motor, top pulley (again aligned as best as can be, Install the belt and you should be good.

 

Keep in mind that a chain coupler is very very tough so I used it, there are quieter and less durable ways to connect shafts,

I want tough! as quiet as that can allow for is fine by me.

That said a good quality solid collar type coupler would create no noise and be tougher. (INSERT IDEA BULB) I may change to that type I just never thought of it till now. That should be used only if you really get things aligned exactly.

I presume T-Struck provides the kit with Chain couplers and I feel it's a good idea is so a wider range of folks can get it handled DIY albeit a bit noisier than a solid link.

 

I hope I never missed anything and these are just my thoughts and experiences gathered during my 40 year career as a boat loving welder and millwright, your experiences/results may differ.

 

Best of luck and I hope to see you not hear you out there…

Lee Chrystal

Marsh Specialty HVAC LTD

Box 5061 STN Main

Leduc Alberta T9E-6L5

Cell: (780) 975-6801

 

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From: electricboats@groups.io <electricboats@groups.io> On Behalf Of THOMAS VANDERMEULEN
Sent: September 2, 2020 2:09 PM
To: electricboats@groups.io
Subject: [electricboats] No Vibration? - How did you get there?

 

This question is to Thunderstruck motor kit users who are NOT having a problem with vibration.  How did you manage it?  Learning what works from someone who's made it work would be terrific!
Are you using the chain-and-sprocket shaft coupling arrangement T'struck provides, or some other coupling arrangement?  Did you use standard motor mounts, or did you hard mount the reduction gear rails more or less directly to the hull?

I have a T'struck kit operating nicely on a test bench, and have not yet started an installation.  Our local installer, as recommended by T'struck, told me on the phone that they would need to use motor mounts and some other items not provided by T'struck that he did not detail in that conversation.

So, the few reports in this group over the past few weeks by skippers of recently launched e-boats of uncomfortable levels of vibration who are using the Thunderstruck motor kit, and T'struck reduction gear got me wondering again about the best way to mount the system, and also to couple it to my shaft prop.

The chain-and-sprocket arrangement is not common in this application.  It's stated that this arrangement can help compensate for slight misalignment between reduction shaft and prop shaft, but I'm skeptical.  Can that approach be as good as, for example, a flexible shaft coupling such as those from R&D Marine or from Vetus?  (These are more expensive, I recognize.)

My existing diesel motor mounts are shot so I can't reuse them.  And my existing shaft coupling is a solid-style, split type, so would require precision alignment.  Would using new motor mounts allow enough adjustment to ensure a precision alignment?

Any success stories out there?

[-tv]
Tom VanderMeulen
"Grace O'Malley"
Cape Dory 27
Monroe, MI

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