SailNet Community banner

1 - 5 of 5 Posts

·
Registered
Joined
·
87,723 Posts
Discussion Starter #1
I am repowering my boat with a Yanmar engine, which happens to be quite a bit shorter overall than my Westerbeke 107 with a silk drive. My question is

Can I make a short "dog" shaft to take up the difference between shaft and gearbox. I don't want to change it because I have a beautiful Monel drive shaft that will serve me well for at least another ten years. If anyone has any input on this, please feel welcome to jump in.
 

·
Registered
Joined
·
586 Posts
Yes, you can do this although I haven't seen it done on smaller engines. Essentially what they do is to create a shaft with two keyed couplers on it and one bolts to the engine and the other bolts to the coupler on the end of your existing shaft. If you look at larger sailing vessels with a shaft brake, they usually use one of these. If the difference is small, you won't be able to fit one of these in there and will have to use something like a flex coupling instead.
 

·
Courtney the Dancer
Joined
·
3,971 Posts
I'd just have a new Monel shaft made and keep it simple. Yeah, it's a shame to not be able to use the old shaft, but you're starting with a new engine and gear, why introduce a possible problem into the mix? Deduct the cost of whatever you need to have made to extend it from the cost of the new shaft and it won't hurt so much :D .
 

·
Mechsmith
Joined
·
240 Posts
I prefer a flex coupler in there somewhere. Motor shakes, Output shaft doesn't.

The manufacturers of small tractors usually put one between the motor and transmission. And they are both mounted on steel plates!
 
1 - 5 of 5 Posts
Top