Cruising auxilery . .

Welcome to PocketShip.net! This bulletin board is for builders of the Chesapeake Light Craft-John C. Harris "PocketShip" design, a 15-foot micro cruiser sailboat built from a kit or plans.

For more information on PocketShip, click here: http://www.clcboats.com/pocketship

This site gathers PocketShip builders in one place. Here you can share photos, tips, questions, and---eventually---your sailing adventures in PocketShip! CLC will also post design updates and tips here as they come up.

We'll try to knock down spam as quickly as possible.

Moderator: John C. Harris

Forum rules
Spam or commercial posts will be deleted.
This is a civil forum: no flames or drunken tirades.
Please stay on-topic.
PocketShip's Web Page: http://www.clcboats.com/pocketship
If you need CLC customer service: http://www.clcboats.com/forms/contact_us.html
We'll try to delete spam as soon as it appears.

Cruising auxilery . .

Postby tattoo on Sun Jan 15, 2012 1:00 pm

My auxilery is a Tohatsu MFS 6 Sail Pro (4 stroke 6 hp, 59 lbs, 25" shaft, 5 amp 12 v. alternator). It's more than what's needed for moving in and out of the harbor. But for transiting the Chesapeake and multiday cruises in fickle winds I want the extra power margin. It moves my Tattoo at about almost 6 knots (4500 rpm) and over 4 knots at about 3000 rpm. Fuel consumption at 3000 rpm is about 1/2 gallon/hour. It's mounted in a transom cut-out with the lip of the cut-out 7" above the cockpit deck (7.5" along the slope of the transom). The bottom of the shaft is just above the level of the rudder. When tilted up the prop doesn't drag in the water on either tack. When the tiller is hard to starboard (engine straight ahead), the prop would clip the rudder "wing." I prevented that by installing a sliding "limit-stop" on the tiller where it came up against the starboard side of the hole cut into the transom. That worked pretty well and it could be easily moved out of the way when full range of the tiller was desired during sailing.

But maneuvering at slow speed was problematical, especially to port. The engine produced an asymentical thrust (to starboard) and the rudder has little effect at slow speed. So, I've installed an engine-to-tiller linkage. I had my doubts as to wheather it would be too unwieldy. But I think it will work just fine. Now the thrust line of the engine is always near paralled to the rudder and there need not be any limitation on the swing of the triller. The photos show the limits of rudder deflection. Maneuvering at the dock and into and out of slips will be much easier.

The mahogany linkage shaft is easily removed by unscrewing two "acorn" nuts. The nuts are stowed back on the 5/16" bolts and the linkage shaft is stowed in one of the cockpit side pockets. When the linkage shaft is removed the the starboard lazarette hatch my be opened by rotating the engine shaft so that the linkage arm is out of the way. The hatch may be opened with linkage in place, but the tiller has to be put hard to starboard.

In the garage it seems to work quite well. With the prop thrust line parallel to the rudder and the prop freewheeling, maybe the drag will be insignificant. Sea trials will tell.
Linkage.jpg
Tiller-to-engine linkage
Linkage.jpg (61.27 KiB) Viewed 1894 times
Attachments
To stbd.jpg
Rudder to starboard, limit
To stbd.jpg (65.23 KiB) Viewed 1896 times
To port.jpg
Rudder to port, limit
To port.jpg (49.92 KiB) Viewed 1917 times
Pete McCrary, launched Tattoo Oct '10.
tattoo
 
Posts: 116
Joined: Wed Sep 16, 2009 7:09 pm
Location: Manassas, Virginia, USA

Return to PocketShip Forum

Who is online

Users browsing this forum: No registered users and 26 guests

cron