Yacht optical engine and shaft alignment procedure and news December 2013

Derecktor engine alignment

Derecktor installed new cutless bearings to insure that we're setting the engine alignments to the correct shaft lines. Bearings wear to the shafts, so used bearings create a shaft line based on bearing wear, not on the absolute position of the cutless bearings. In fact, cutless bearings tell a story. Visual examination of the landings- the raised sections between the grooves- can provide a lot of information about how the shaft is wearing the bearings. Full length even wear is apparent, as are uneven wear patterns. The first thing we do after shaft removal is get a good look at what the bearings have to say.

Alignment checks

The bearing targets are made for the shaft size and hold the optical targets, which are wires with gaps between the wires based on the distance from the scope to the target. The particular target for a distance has a gap between the wires that closely fits the telescope reticle so that the wires and reticle can be finely tuned over the whole length of the reticle.

Engine Alignment
The engine alignment procedure is straightforward. Marine Alignment has fixtures made to fit a wide variety of marine gear output flanges. We also have a universal fixture for the rare occasion when we don't have a purpose-built fixture. The fixture holds a mirror, and has a cross-hair. The shaft line is established between bearing targets, and when the cross-hair on the marine gear output flange mirror intersects the shaft line, and when the mirror tells us the output flange is perpendicular in horizontal and vertical axes to the shaft line the alignment is complete.

Strut alignment- optical alignment telescope
Sometimes the strut misalignment is so great that you can see the offset by comparing the position of the telescope and the center of the strut. In this shot it's pretty apparent that the strut is high. Once a correct shaft line is established all the components- bearings, struts, and engine alignment- can be brought to that shaft line. While there are standard procedures each boat can be different. Establishing the correct shaft line and working with the yard or builder to deliver the most efficient procedure is the key.

MarineMax Yacht Services
This is a Sunseeker yacht after a grounding under repair at MarineMax Yacht Services in Dania Beach, Florida. Both struts had to be reset and the offset is visible. One of the v-drives was damaged and we adjusted both of those as well for a complete repair procedure.