Somewhere along the line I mentoned that I was going to attempt to remove my masthead sheave boxes to see what all was in there. Well, I have successfully removed the main mast assembly. It took some effort but more so patience to remove the screws that hold the assembly into the mast extrusion. I only had to drill out one screw which isn't bad for 35 years of residence. Here is what I found.
(http://i153.photobucket.com/albums/s233/dtskibo/Summer2011014.jpg)
You will note the hoop welded under the cap to tie your wiring harness to, something that I was not utilizing because I had no clue it was in there. An electricians kellem often referred to as a strain relief would be the ticket. It works like a Chinese finger torture devise and would slide over your cables and the woven wire of the kellem would hold fast providing support. Do a search for kellem for a picture of that handy device. The large hole (with the blob of silicone) through the base is for wire egress.
Here is the port side view.
(http://i153.photobucket.com/albums/s233/dtskibo/Summer2011004.jpg)
The black thing on top is the mount for my Simrad wind transducer. The stainless sheetmetal bracket further back in the foreground is the mount for my VHF whip. The 4 screws on top directly behind that are for my Windex mounting arm that faces backward and contains a light. The last little blob on top to the far right is left over form the old Windex mount that I could not remove the screw to remove. That will go this round.
(http://i153.photobucket.com/albums/s233/dtskibo/Summer2011003.jpg)
On the starboard side we have two screws that mounted zip ties that held three electrical cables in place that exited through that large hole in the base plate. They fed the windex light, tricolor, anchor and strobe. The next two screws are for the tricolor mount that held a flimsy sheet metal bracket similar to the VHF mount. This will be reworked as well this session with a heavy duty bracket as the tricolor bobbled around in choppy conditions. The 4 sheaves with the 2 axles are the halyard sheaves. Each sheave is cut with a deeper wire groove and a more rounded rope grove. As you can see each has a bronze bushing/bearing/ They are all very worn. Hopefully you can see the angles that the sheaves can be coaxed to sit at when on the axle pins. Sorry for the fuzzy picture of the missaligned sheaves.
(http://i153.photobucket.com/albums/s233/dtskibo/Summer2011006.jpg)
(http://i153.photobucket.com/albums/s233/dtskibo/Summer2011011.jpg)
Initially I am planning on either rebushing the sheaves with new bronze oil lite bushings, or boring each and installing new stainless sealed ball bearings. I will price out the bearing and decide from there. Either way, I would like to add spacer washers as the cheeks of the sheaves are rubbing on the sides of the aluminum housing. This is what I believe is causing the squeaking that I occasionally get while raising the sails.
Hopefully I can get the mizzen box off soon to see what is in there.
Dale
I actually just replaced the sheaves with Delrin ones from Zephyrwerks. They don't make a sound as the main is hauled up. And no corrosion to make that scraping noise in a few years.
Thanks for the pictures Dale, it's been quite a few years since I had my masthead out. I cut some plastic shims, I think I used a notebook binder cover to make washers on each side of the sheaves. Delrin sheaves would be nice but I was looking for something cheap, (I like to say I'm thrifty)
To stop the wires from slapping against the mast I cut some cushion foam 1 or 2 inches thick, slightly larger than the mast opening and tied them on a light line about 4 feet apart and pulled them through the mast. I used that hoop in the masthead to tie them off. When I was rewiring I struggled with fishing the wires through, then I got some 3/4 inch PVC and ran screws through the coupler so I could disassemble them easily. It made pushing wire pretty simple.
Zephyrwerks sure makes some nice stuff don't they. I have never priced anything but I would assume they charge for what you are getting.
My initial look into bearings is not going well. To maintain the axle shaft diameter of the original sheaves means a small diameter bearing. This translates into a limited load situation, something a bushing overcomes nicely for far less money and effort.
Dale
I think it was a couple of hundred. Pricey but not impossible. If I still had my lathe I'd have tried it myself. Delrin is pretty cheap. The only real precision you need is the bore, and that can be reamed before you press the bushing.