Finally Shafted and Breakthrough

 

DON ROBERTO PREPARING FOR HIS MEETING WITH DON ERNESTO

The new propeller shaft seemed a long time coming.  It was due on Thursday afternoon, then yesterday morning.  Brenda suggested that I give to Ernesto her mobile telephone number so that he could communicate directly with me.  This turned out to be of great assistance because through several more delays I was able to go about my business without doing a slow bake in the boat while I waited for the shaft.  At midday on  he said that he had run into an unexpected problem with fitting the connector, he would have to make a keyway in the shaft, and he needed two more hours.  Then he telephoned for 2 more hours. At 4 PM Luis said that they could still install the shaft that day but I told him that it was after 4 PM, very hot, and it would be better to wait until today when it was cooler and everyone was fresh.  He agreed.

I went into the boat at 4.30 PM to prepare a bed for measuring the pitch of the propeller, wondered why I was dripping sweat all over the piece of plywood where I was trying to make my markings, looked up at the thermometer and saw 38.0C which is equivalent to 100F.  I had known that I was running out of time with the propeller, could find nobody who could tell me for sure its pitch, so went on the internet to learn how to do the calculation myself at http://www.propellerpages.com/?c=articles&f=2006-03-27_manual_pitch_measurement. 

Ernesto finally delivered the shaft at 5.30 PM.  I told him that he looked like he'd had a hard day, and he said that he had.  He said that he'd have to charge me another 1000 pesos for the work to fit the connector and I had prepared for this.  I handed him a sandwich bag with the 6600 pesos originally quoted.  It was a bit breezy so we decided to complete the transaction in the cab of his pickup truck.  When we settled in I asked him where the money was.  It was in his back pocket.  I asked him to count it in case I had made a mistake.  He did this and the amount was spot on.  I then pulled out my wallet and had exactly 1000 pesos to cover the extra work.  That totalled 7600 pesos which is about $675 Aussie dollars or $570 greenbacks.  I let him keep the old shaft and coupler which turned out to be a mistake.

Later I realized the amazing amount of trust in that transaction.  Nobody saw me give Ernesto the cash.  He initially didn't even bother to count it.  I got no receipt.  Legally it never happened.  It boils down to a people thing rather than a Mexico thing.

After Ernesto left I took the propeller into the cabin to do take the measurements.  The propeller is right handed with a diameter of just under 17".  Its pitch is 16", which is higher than the 14" recommended by the propeller pitch calculator for the new Volvo engine. This pitch is not surprising since the Sabb manual specified a prop of 20" diameter and 15" pitch.  I'll stick with this propeller for now and if I detect a serious efficiency issue I'll get a new propeller after I return to Australia.

This morning the workmen slid the shaft in and it appeared to protrude 6" into the engine compartment instead of the expected 3".  I measured the length of the new shaft, 66.5" and gave Ernesto a call.  He rang back and said that the old shaft was 63.5" long.  I have photographs that prove that the old shaft ended at the bulkhead.  The only thing that I can figure out is that the propeller was set back farther from the cutlass bearing than the prescribed maximum distance which is equal to the diameter of the shaft (1.25" in my case").  In any event, it looks like I have 30mm (1 3/16") to spare between the front of the engine and the front of the engine compartment.  I might lose 12mm of that by dead space inside the coupler but I think that I'll squeak by, partly because the backward tilt of the engine will be of some help.  If it comes to that I'll move the propeller an extra inch back from the cutlass bearing.

Luis told me that they could return the boat to the water today if it was really urgent but I suggested that we take our time and wait until Monday.  He agreed that Monday would be better.  The way I figured it, the boat yard crew would knock off at noon for the weekend and I didn't want a rush job, particularly if there were any key personnel missing.  I want the propeller and coupler to be put on nice and tight and the PSS dripless packing to be properly installed.

I had a look at the literature that accompanied the Volvo coupling and saw almost immediately the cause of Ernesto's problem.  The coupling is provided in millimeter diameters.  There is only one exception: you can get a coupling for a 1" diameter shaft.  The closes diameter for my 1.25" shaft was 30mm, which was about 1.5mm (1/16") shy of the required diameter.

I used 30 minutes of the remaining cool time in the boat to look at the construction of the base upon which the engine cover slides.  One of the sides was a bit shaky and I figured that strengthening it would be much easier without an engine in place.  One thing led to the other and I discovered that the base is free standing, held in position by the floor boards and the galley counter.  (You've got to wonder what will happen if the boat rolls over.)  It appears that I will be able to slide the entire base forward and lift it out.  I consider this a breakthrough because it will be of enormous assistance in the preparation of the engine bed since it will fully expose all of one bed and half of the other down to the floor level, allowing easier use of tools and easier fiberglassing.  I hope that I can pull it off (literally).

The photo of the engine compartment area shows the amount of protrusion of the shaft.  I expected 3" and got closer to 6".  The last photo, of the packing area, clearly shows that the old shaft coupler was directly under the bulkhead.

Brenda's Bird of the Day. In the evenings we often find ourselves sitting on the bench outside our room, sipping the last of the dinner wine and watching the sunset. Very soon after the sun goes, a couple of nighthawks can be seen making good use of the airspace as they search for flying inscts. The local nighthawk is the Lesser Nighthawk and that is probably the one we see, but I haven't been able to be sure of any distinguishing features.