Yachts66 - it all boils down to where you're planning to go and what you're planning to do.
In spite of some of the negative opinions of Autoprops in this thread. We love ours. Most of the opinions expressed don't translate to actual experiences by the Autoprop owners we've met cruising.
The plastic zinc screws aren't a problem because they only hold on the zinc and you get new ones with every zinc. The flat back of the zinc makes fine electrical
contact with the prop.
The set screw on the prop nut isn't a problem since the prop shaft and prop are keyed, the prop always goes back on in the same place. Also, I haven't heard of any one losing the prop because the nut backed off (unlike most fixed props that are held on by just two nuts in series). I've heard of folks losing regular props, Max Props and others, but not the Autoprop.
What has been a problem is folks losing a blade. In every case I've examined, that's traceable back to a lack of maintenance
, or improper rebuilding of the prop. Each blade is held on by two nuts, one big one that does the work and a second locking star nut that's reverse threaded. You then must bend over a tab on the star nut to lock with the big nut underneath.
The folks who lost
blades didn't think they locked the two nuts together or just plain didn't maintain their prop (you're supposed to grease it at every haul out).
The other problems reported with a loss of thrust when pounding into head
seas is a problem with all props. I notice little difference between our Autoprop and other props. Note, it would be better in such cases to have a great big fixed prop with large blade area, any other sailing prop will likely exhibit similar results to what we've seen with our Autoprop.
One other performance killer is growth on the prop. The Autoprop uses hydrodynamics to pitch
properly. A bunch of barnacles
on the prop can really mess things up. We anchored in Zihuatanejo last year our prop got so dirty we could only do 3 knots instead of our usual 7.5. We had to pull into Isla Grande anchorage to clean our bottom (it got real bad in only a week! Zihua bay is very nutrient rich - which is why I wouldn't dive on it before we left).
So keep it clean, maintain it and you should be happy with an Autoprop, like most of the other owners I know.
Note - I have no interest at all in any way with Autoprop, other than as an owner.
I do have a backup fixed prop, with nuts and a puller just in case. I figure I have that no matter what prop I normally use... However, I've so far, never needed it!