selden boom query

[bobsadler]

hi,

i wish to add another sheave to the aft end fitting of my selden boom (it has one slot "unpopulated"

i can't however see how to pull the pin/axle the sheaves are mounted on.

i was expecting a c-clip or similar but the retainer appears to be a complete disc.

any thoughts ?

 

[ianat182]

Is it possibly a long clevis pin (axle) and retainer inside?

ianat182

 

[ghostlymoron]

It might be just an interference fit and tap out gently. But I should give Atlantic Spars a ring before trying anything drastic

 

[merlin3688]

The c-clip is under the head I think, certanly that is how they used to fit the pins in, I don't think its just a push fit, the boys at Fox's Rigging would confirm.

 

[ghostlymoron]

hi,

i wish to add another sheave to the aft end fitting of my selden boom (it has one slot "unpopulated"

i can't however see how to pull the pin/axle the sheaves are mounted on.

i was expecting a c-clip or similar but the retainer appears to be a complete disc.

any thoughts ?

Is that Dyneema in your phot?

 

[pvb]

If you look at the diagrams in Selden's spare parts list, some of the axles have a locking pin. The end of the axle does appear to be held with a washer and then a circular clip on the outside though. Maybe yours is non-standard?

 

[ghostlymoron]

If you look at the diagrams in Selden's spare parts list, some of the axles have a locking pin. The end of the axle does appear to be held with a washer and then a circular clip on the outside though. Maybe yours is non-standard?

The diagram shows a plug at the other end with maybe a washer and locking ring underneath. Possibly needs to be dismantled from the other side by first removing the plug which may expose the locking pin.

 

[pvb]

The diagram shows a plug at the other end with maybe a washer and locking ring underneath. Possibly needs to be dismantled from the other side by first removing the plug which may expose the locking pin.

Does it? Are you sure you're looking at the outboard end of the boom?

 

[ghostlymoron]

Does it? Are you sure you're looking at the outboard end of the boom?

You're right I was looking at the wrong end assuming that both would be the same. The items are 41 - pin, 42 - washer, 43 - circular clip which doesn't look like Bob's photo. I'd try gently tapping it to see if there's any movement then ask advice from a local rigger/sparman.
Closer look at original photo could be a spring washer after all but could do with another view from a different angle plus similar shots from the starboard side. It's possible that the pin only withdraws from one side

 

[bobsadler]

yes, thanks, the spare parts list is helpful (i should have thought of that !)

one thing i noticed is that it refers to a "circular clip" (item 43) rather than, say, a "c-clip" so it may be the retaining clip is more like a spring washer as gm mentioned

here are two more photos showing the aft end of the boom from the opposite side and from above

all ideas considered

 

[merlin3688]

The picture showing the pin end is the clip that needs removing, this I think is a little spring clip that comes of by using a small screw driver, I am sure this is how they were fitted. I think at the bottom of the pin and to the left you can see the join.