Milling for Precision Strut Alignments
On a recent strut alignment on a Cheoy Lee we ran into a situation with bottom clearance. The vessel unfortunately sat on the bottom and the upward pressure caused the strut to bend or bow. We dropped the strut and straightened it in our machine shop (see prior post). Re-hanging the strut in the right aligned position requires a level of precision to get it right. Once the strut pocket was cleaned and the strut was dry-fit for a test alignment we realized that the imperfections in the original strut casting left humps and hollows. The high points contacted the hull in the wrong spots and prevented us from adjusting the strut to the right position.
The solution – mill a small amount off the strut pad – approximately 0.050-0.075″. Not enough to cause any concerns with the integrity of the strut. As you can see in the picture the original pad had plenty of beef.
Once properly aligned and assembled the vessel was launched and we went for our traditional sea-trial. I always like to sea-trial a vessel to make sure it is vibration-free and the customer is satisfied. It is also the right time to ask for a reference, which this Captain gladly allowed.