flexible shaft coupler

[Lopez Mike]

Absolutely correct on simple U-joints. Without a matched and properly phased pair, there are rotational variations. I suspect, however, that with the flow across my propeller being so non-uniform and with the blades passing by the dead wood, and the torque variations during the normal power cycle of my simple single cylinder engine, that any added vibrations from a U-joint might be hard to isolate from the rest of the flailing about at higher speeds.

At less than a few degrees, it shouldn't be an issue. More than that, maybe line things up better.

For my issues, which are hull flexure and being too lazy to do a really good alignment job, a chain coupler looks like a pretty good solution. And dirt cheap!

Mike

[barts]

I used to use a Lovejoy style coupling with a rubber spider; with the bigger engine & prop I changed to a U joint from surplus center and it's much quieter since there's no play at all. The coupling is indeed almost completely straight.

- Bart

[Oilking]

This all brings to mind the story my dad and uncle would tell about a time when the bore through the shaft log didn't come out straight so they pronounced in ali seriousnes that the cure was to us a some rubber shafting for which the new kid was sent to find.

Dave