Bow roller pin diameter

RobbieW

RobbieW

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Having gone through a season with the bow roller not really rolling its time to do some work on it. The old one has some deep grooves in it now.

The anchor is a 60lb Spade on 10mm chain, the boat is Rival 41 of around 12-13 tonnes cruising weight. The existing pin was a 10mm threaded bar which had distorted and cracked causing the bow roller to jam.

Is 10mm enough if I go to a proper pin or bolt?

Thickening the pin would require drilling out the bow roller fitting, see pics.
View attachment 22326View attachment 22327
Possible but getting to the centre piece needs a long drill. An alternative might be to use a long 10mm bolt, sleeve over that in each section and tighten up against the sleeves. Then put a sleeve into the new roller that forms the bearing surface.

Thoughts?
 
Mine is a 12mm bolts on a 36 ft boat. If you chose the bolt carefully then you can get one with a long enough unthreaded spindle before the threaded bit for the nut.

A bolt has a long unthreaded part then the thread. If it has thread from the head to the end it isnt a bolt but a machine screw.
 
engineered solution

RobbieW said:
Having gone through a season with the bow roller not really rolling its time to do some work on it. The old one has some deep grooves in it now.

The anchor is a 60lb Spade on 10mm chain, the boat is Rival 41 of around 12-13 tonnes cruising weight. The existing pin was a 10mm threaded bar which had distorted and cracked causing the bow roller to jam.

Is 10mm enough if I go to a proper pin or bolt?

Thickening the pin would require drilling out the bow roller fitting, see pics.
View attachment 22326View attachment 22327
Possible but getting to the centre piece needs a long drill. An alternative might be to use a long 10mm bolt, sleeve over that in each section and tighten up against the sleeves. Then put a sleeve into the new roller that forms the bearing surface.

Thoughts?
Click to expand...

Option B. Get your local machine shop to put a male thread on each end of a piece of 10mm dia stainless round bar at the correct dimensions to leave no thread inside on the roller bearing surface and put a locking washer and nut on the ends. That way you can extract the bar from either side . Seemples:)
 
My (two) bow rollers, on a 36ft boat, are mounted on a 1" plain spindle, which is supported in three places, and which has a split pin at each end. I wouldn't have thought that 10mm, and certainly not 10mm threaded, would be adequate.
 
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