Commander 147

[ebb]

Jerry,
Nice gooseneck fitting!!!

No, by radius I meant on the flat of the plates.
So that when you look at them in the mast slot they would project out from the mast in a curve.
They would in effect be long cheeks for your sheeves. Top and bottom of curve would begin and end at mast.

So if they were welded up into a sleeve as ebb has done they would slip thru without a problem.

Of course the problem may be in how wide the sheeves are
and how wide the sleeve has to be to accomodate them.

My sleeve-box is at the welders right now, so I can't ckeck on it's actual width.
Got a new sheeve that is 5/8' thick delrin. It is 6 5/8"D which matches the sleeve dimension. The groove is made to cradle 1/2" line.
If I get it right the halyard will not run afoul of any hard edges up there. We'll see!

The aluminum sleeve I believe is a skoch wider than 7/8".
The original slot in the mast is between 5/8" and 3/4" depending on where you put the tape.
Widening that slot that much doesn't seem to be too radical.
Altho I will admit the original slot itself is an engineering problem.
Mast showed a little enlargement of bolt holes. Have found a bolt with a smooth shank long enough so no
thread bears on the holes. May have to add a couple bushings to the mast walls later.

Argument is that the welded sleeve adds some structure to the slot if the slip is tight all round.
The thru-bolt gets support in four places: mast wall & sleeve.

With welded top and bottom, the sleeve can be fastened to the mast with clips if thought necessary.
It's removable and helps keep rain and mud swallows out of mast.

[Commander 147]

You know Ebb pictures of what you have done sure would be helpful.

But I get what you are talking about now. According to the manual the original designed width of the sheeve slot in the mast was 13/16" but like yours mine was not that wide. I'm using two Harken halyard sheeves model number 6062 which are 1-1/2" diameter and 11/16" thick. If I use 16 ga. S.S. for the sides of the box assembly my total thickness should be just under the 13/16" designed width of the mast slot. That would be a goal for me since the head stay and the back stay are connected above this entire area. And depending on the design of the box assembly the way it is attached to the mast could also add additional strength to the top of the mast.

If I get a chance this weekend I think I will spend some time with my CAD software and see what I come up with.