Hello, I am re-powering my sailboat with a diesel and was wondering about flex couplers. Would it be worth it to buy one?
Shaft coupler
- Thread starter willhamlin
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Ive wondered this too. One of the problems is that the coupler is the only thing holding the shaft in the boat. While in forward the prop pushes the shaft againt the motor and wouldnt be an issue, in reverse it will try to pull backward. Secondly, the motor/gearbox connection would keep the shaft centered, where a flex coupling would allow more movement.
That the basic setup has been used for decades by virtually everyone, without trouble, its probably a fix to a non issue, which actually offers the potential for more trouble, not less problems.
That the basic setup has been used for decades by virtually everyone, without trouble, its probably a fix to a non issue, which actually offers the potential for more trouble, not less problems.
Willhamlin,
We have had 2 flex couplers on our Nor'Sea 27. Some points to think about....
The second one, I think I remember it's a CDI works great.
I also bought a spare collar zinc the size of our shaft and installed it just forward of the packing gland. Once when we spun out the wood riff key, this saved the shaft from exiting the boat!
Installing the flex did quiet the boat a bit.
Mine looks exactly like this one......;
Good luck!
Greg
We have had 2 flex couplers on our Nor'Sea 27. Some points to think about....
- It will add 1.5 to 2 inches to the prop shaft. You may need a new shaft?
- With a coupler on, you MAY have problems aligning the shaft and tranny.
The second one, I think I remember it's a CDI works great.
I also bought a spare collar zinc the size of our shaft and installed it just forward of the packing gland. Once when we spun out the wood riff key, this saved the shaft from exiting the boat!
Installing the flex did quiet the boat a bit.
Mine looks exactly like this one......;
Good luck!
Greg
The best $17 insurance policy you can buy:
http://www.mcmaster.com/#shaft-collars/=m5fjn5
Install one in front of your shaft seal or stuffing box.
Years ago flexible shaft couplers were very popular but over the years people found out they are often more trouble than they are worth. I think the keep it simple applies here.
Capt. Wayne Canning, AMS
www.projectboatzen.com
Capt. Wayne Canning, AMS
www.projectboatzen.com
You may already have a flexible coupling in place as shown in the attached picture ........... the beefed up rubber hose which is between the gland and the shaft log. It is the simplest and most reliable flex coupling going (always assuming periodic inspection).
Placing an additional flexible coupling in here would allow for flexure at two points which would not be good.
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I didn't notice the price of those things but as mentioned above a shaft zinc would do the same job at probably a fraction of the cost.
The $17 insurance policy costs $17. That's for the 304 stainless collar. Checking West Marine, it looks like the're currently asking $13.99 for a 1" zinc anode. I guess you could call that a fraction - about 13/16ths I guess would be about right.
I preferred the stainless shaft collar because it was actually made for that purpose, and it looked so good backign up the stainless shaft seal collar on the PSS I installed.
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