Masthead sheaves

Hoping someone has some info on this. I have the mast down on my 35-2. I cannot figure out why the pin for the sheave does not go all the way through. Other masts I see have the pin through and held by a cotter or clevis. Seems weird to have a hole and not go through and secured. Is it threaded in? There is a small access cover which I haven't opened yet. Hoping someone here might know. If I did this correctly there should be pictures. And yes I intend to replace rusted screw and antenna which is why mast is down.
Thanks for any help.
Hank
SV/Right Moves

It doesn't need another hole.

It doesn't need to. It is a captive pin. Take off the access cover and use a thin drift to gently tap the axle out. Why have two covers?

Guy

Guy Nailed It!

The masthead pins are captive, at least until the cover and pin uncouple themselves for some unknown reason, which was discovered last winter. No danger of the pin/sheave interface becoming inoperative, it just adds a bit of complexity when replacing the sheave. The pics show how the cover and pin were reattached by drilling & tapping to achieve a mechanical connection (replacing the original funky tip-weld).

All better, especially the new sheaves, replacing circa 1989 sheaves grooved by the OEM wire-to-rope halyards.

figured as much

thanks guys
thought it had to be held in some manner or it would have caused problems ages ago. Grizz are you saying it is actually tacked to the back of the cover? and what about the other side does it sit in a slot? otherwise it would cant. Or Guy are you saying the pin is pressed into some rings interior to the mast so you would punch it out and punch a new one in and the hole I see just helps line it up?

Need to eyeball the sheave some more to see if it needs/ or I can get to replacing. that was not on my original ever expanding list. tough to see in there.

More Details

Your Pin is not tack welded to the cover. Your pin is Stainless Steel, and your covers are aluminum squares (as far as I can tell from the photo). Some of the Sparcraft masts had covers that were tack welded to the pins, and if you took the screws out of the cover plate, and rotated and slightly pulled the cover the pin would come out with it. These also have a single hole drilled on the opposite side of the mast as the cover to allow you to insert any small long straight tool to push the pin out of the mast should it become dislodged from the cover plate.

Your cover plates cover a hole just large enough to allow you to put the pin in the mast. Generally there are a series of holes the pin goes through. From the cover inward. Hole through the mast side, Hole through the pin support plate (welded to the mast section itself), hole through the sheave, hole through the sheave separator (Generally either aluminum or phonalic canvas and resin board), hole through the opposite side sheave, hole through the opposite side support plate, and finally a smaller hole through the opposite side mast wall.

The small hole in the opposite side mast wall allows you to remove the pin, but keeps the pin captive between the cover plate and the mast wall on the opposite side. This way you don't have to have 2 cover plates, and 4 screws to hold the pin in, only one cover plate, and two screws on one side.

Does this make sense? I don't have a photo of this handy....

Guy

Kenyon axle is a bit differnt...

Sorry for the confusion, didn't pick up on Guy's 'drift pin' suggestion, which indicates an access hole on both sides of the mast.

This Olson came with a Kenyon mast and the axels are accessed from 1 side only, with a cover that's connected to the axel by a thin tip of metal welded to the cover plate. Mine parted and removing it was a bit of a hassle.

Here's an image from Rig Rite as an example...

Gottcha

Thanks Guy, that is what I envisioned. Eyeballed it a little over the weekend. At least with a superficial look sheaves didn't look bad especially in light of the age. Still has the wire to rope halyard, and the rope part is looking a bit natty at this point, I am getting tempted to replace it with all rope.

No worries Grizz

your situation makes me wonder what those support plates in my mast can take. Hope they are beefy

Lets hope so!

They are the same plates that hold the pins for the standing rigging, so lets hope they are correctly constructed for the loads required!