Mike, In my experience the board works fine the way it is. I leave it down all the time except when sailing skinny water. I'm no racer, though. I think Jerry may have built a boat or two with an arrangement using a screw jack type assembly to raise and lower the board but he abandoned that design. I've never heard of an M17 suffering a knock down/rollover that would send the board crashing up into the trunk. I don't think wind would do it but a big wave catching you broadside certainly could. It's not a very likely event, however. What kind of water do you sail? Good luck with your modifications. When you work something out be sure to post photos for us. Mark Dvorscak M17 #400 Grace M23 #74 ????? (maybe "More Grace") -----Original Message----- From: MC Carpenter Sent: Sunday, December 07, 2003 6:12 PM Subject: M_Boats: Re: screw jacks The model I am building now is using an old trailer screw jack (advise!!!! get the grease off first) and I measured it tonight and it takes a little over 30 turns to go from up to down, On my other centerboard boats I always left the board up except to windward. This is just the test to see if it works stage so there will be changes to be sure. The top of the plate I have added the a lower end of a open-ended turnbuckle with the upper end a swivel, The inside of the swivel is tacked (brazed )to the inside screw mechanics of the jack. The whole thing is way to big to use in real life as yet and it will have to come down in size a lot to fit inside the center board trunk. I tried to get a single lever ratchet to work but it was too much like hard work. Plus I ran out of beer that day. The idea was to take the wheel hub of the kids bike which is about 10 inches across and hook it to the ratchet so one turn of the ratchet would be about 15 inches of movement, but like I said that didn't go far as the spokes on the wheel couldn't take the pressure and crumbled under the load. Well the kid gets a new bike for Christmas from a mysterious source. . And any questions about the bike,, well I never saw that bike, what missing wheel??? So I moved on back to the screw idea because I like the thought of some method of a lock down in rough weather. Mike _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats