What is this and how does it work

Nodak7

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Sep 28, 2008
1,249
Hunter 41DS Punta Gorda, FL
It is called a "Fiddle Block" and it is usually used for holding sheets in place. Looks to be broken though
 
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Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
Looks like that was a standup fiddle with a cam cleat. Looks like it was for your mainsheet. You can find those parts at Schaefer Marine, Harken, Ronstan and many other places. The pin at the bottom usually has a spring where it attaches to the deck to keep it somewhat upright. The plate can be removed in order to replace the pin and spring. Then you can rebed the whole thing. I would guess that one is a Schaefer.
 
Jan 19, 2010
12,369
Hobie 16 & Rhodes 22 Skeeter Charleston
Ok so that would attach to the back of the boom?
Yes. That is your main sheet (the rope that controls the boom) tackle. The part you showed us in the picture attaches to the cockpit floor. The other end to the boom ... I"m guessing about mid-way in the boom is a bail (a metal loop) and a shackle is used to attache a second block (pulley) to the boom.
 
Jan 19, 2010
12,369
Hobie 16 & Rhodes 22 Skeeter Charleston
If you call the store that manages this forum, they will ask you to send a pic. Then they will talk you to the right parts you need. I've shopped many different places and SBO has good prices but they also have unbeatable customer service. You will talk to an actual person who is a sailor and they will help you get the part you need.
 
Jan 19, 2010
12,369
Hobie 16 & Rhodes 22 Skeeter Charleston
Here some pic. I feel like I'm missing something
Okay so the main sheet (rope) goes up through that block on the boom and then down to the cockpit floor where that fiddle block is supposed to attach. But your's is broken and needs to be replaced. The sheet comes out of the fiddle block and through the cam (the clamp). You pull the line and it brings the boom to the center of the cockpit.... or you release the cam, let out some line and the boom swings out from center line. That is the mainsheet control for your boat. It lets you spill wind as needed or trim the sail to the right angle.
 
Mar 1, 2012
2,182
1961 Rhodes Meridian 25 Texas coast
Here some pic. I feel like I'm missing something
Your main sheet should tie off to the loop ,on top of the block on starboard, run up to the boom, down to block on port side, back up to boom, then forward to the single block, then down to the fitting that is broken . That's what my old SJ 21 had anyway
 
Jan 11, 2014
11,401
Sabre 362 113 Fair Haven, NY
When you talk to the SBO store, talk about getting a better quality fiddle block, one with ball bearings in it. The old style simply had a sheave riding on a plain axle, too much friction.

Also, the mainsheet looks to be seriously oversized, probably about a ½". For a 21 foot boat a ⅜" line will be plenty strong enough and easy to handle. Smaller will be harder to handle, larger will no run through the blocks easily. If you have the money, a line called Salsa is a favorite.
 
Jan 17, 2019
13
San Juan 21 Sc
That makes sense. It would seem I don't even need to use this tho. I could run the sheet to the port and starboard pullies in the back of the cockpit then to the back of the boom. It would take everything out of the way.
 
Jan 19, 2010
12,369
Hobie 16 & Rhodes 22 Skeeter Charleston
That makes sense. It would seem I don't even need to use this tho. I could run the sheet to the port and starboard pullies in the back of the cockpit then to the back of the boom. It would take everything out of the way.
As it is, you are already lacking a traveler which will make sailing to windward less efficient. A traveler is a device that lets you adjust where the fiddle block is in relationship to the center line of the boat. When sailing to windward, you move the fiddle block to the windward side of the boat thus allowing you to pull the boom fully to the center line of the boat. With the current configuration of your boat, you already will lose a few degrees when trying to get your boom to center line, if you use the spinnaker blocks, you will lose a few more degrees. So yes, you could do that but you will not be happy with your windward performance.
 
Oct 19, 2017
7,744
O'Day 19 Littleton, NH


Found these pictures online. That's the main sheet, but it looks to me like it needs a couple more turns through the blocks.
Anyhow, that's the basic idea. The spring at the base of the block keeps the block from falling over and hockling the sheet when tacking. That's the part that's missing.

-Will (Dragonfly)
 
Jan 11, 2014
11,401
Sabre 362 113 Fair Haven, NY
That makes sense. It would seem I don't even need to use this tho. I could run the sheet to the port and starboard pullies in the back of the cockpit then to the back of the boom. It would take everything out of the way.
As it is, you are already lacking a traveler which will make sailing to windward less efficient. A traveler is a device that lets you adjust where the fiddle block is in relationship to the center line of the boat. When sailing to windward, you move the fiddle block to the windward side of the boat thus allowing you to pull the boom fully to the center line of the boat. With the current configuration of your boat, you already will lose a few degrees when trying to get your boom to center line, if you use the spinnaker blocks, you will lose a few more degrees. So yes, you could do that but you will not be happy with your windward performance.
A traveller greatly improves mainsail trim. However, on the SJ21 it would put a traveller track across the middle of the cockpit. That would be a pain in the shins. On smaller boats an alternative is to use an end boom pseudo-traveller. It works sort of like a barber-hauler.

The second photo that @Will Gilmore posted (proxy.php) shows this arrangement. It works, it is less expensive than a real traveler, keeps the cockpit clutter down and saves the shins. :)

If you plan to race this boat, then a traveller or the pseudo-traveller is important. If you only want to go out sailing, stick with the basic mid boom sheeting.

And if you are feeling overwhelmed by all this discussion that is normal for a new sailor who is refitting an old boat. Enjoy and learn.
 
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