I’m really pleased with where we have reached today.
I took the plunge and started the other panels for the motor frame. Both the front and back panels are made up of 2x 3mm panels as I couldn’t find 6mm sheet stainless steel. Turns out that was probably a good thing as I don’t think my tools would have coped with 6mm sheets.
So the most critical task was to get bolt holes through all 4 sheets so that I could ensure that the bearings for the shaft are perfectly aligned along the full length of the frame. These were tricky as the 16mm Bosch drill bit I just bought really couldn’t cope with stainless steel. These 4 are the only 16mm holes on the whole frame so I used a 13mm and then widened it.
I’ve also drilled the two holes for the top bar that is used to lift the motor for belt tensioning. Again straight through all 4 sheets so that everything can now be held perfectly aligned.
Here you can see the result.
This photo is a slight cheat as the bearings are temporarily positioned on the wrong side of the plates. What you can see here is the outside face of the front and rear panels. The bearings go on the side face.
The remaining really critical task is marking and cutting the motor bolt slots on the back panel. Not only are the 45 degrees rotated ie NE, SE, SW, NW instead of N, E, S, W but the bolts are 1/2″ instead of the 3/8″ that are used on the motor front face (life would be a lot easier without those differences, but I assume that it is probably for situations where the motor is only bolted to a frame at one end).
Cutting the slots in the 2nd front sheet is straightforward as we just draw round the ones in the first sheet.
Once all the slots are cut we can make the holes for the rest of the angle framing which goes all the way around the back panels. The front panel framing is a bit trickier as it has to avoid the motor and pulleys.
Once the panel edge framing is done we add 4 lengths of angle to connect the front and rear panels at the corners.
Then one diagonal brace per side.
At that point the frame itself is complete. We can then take it to the boat (without the motor in so it is easier to lift) to sort out where the big angled steel lengths need to go (across the frame and sticking out the sides) so that they can rest on the engine mounts with the lower frame shaft perfectly aligned with the propeller shaft.
We still need to source the engine mounts and the coupling to the propeller shaft.
Before we can fit the motor into the boat we need to properly sort everything for the propeller shaft and propeller.
So when we can get on the boat again the biggest part of this still to be sorted is removing the old, stuck, bronze mount for the stuffing box. We think we will need to get a replacement custom milled piece of bronze that will have a flange bolted to the boat and a suitable smooth tube that a modern dripless seal can be fitted to the outside of with the propeller shaft coming through the middle.
As I look at the photo, I’m wondering if we might be able to reuse this. If we can get the last bolt out then maybe I can grind off the flange with the 2 bolt holes that the stuffing box was attached to. That would give a smooth tube to attach the dripless seal to (albeit maybe a rather large diameter difference between it and the propeller shaft). If we can do this it will be fantastic, saving a lot of time and money.
The propeller shaft exits the boat though a cutlass bearing. Ours is worn but there was a new spare on board that we will use. Hopefully as reasonably straightforward job to swap that while everything else is out of the boat.
I think we need to add an internal bearing for the propeller shaft between the dripless seal and the coupling to the motor. The old stuffing box would have supported the propeller shaft in a way the dripless seal won’t. If aligned perfectly, and fixed very rigidly to the hull, it should reduce the wear on the cutlass bearing.
Before the fitting of the motor frame we still have the 2 new composite seacocks to fit for the cockpit drains and the old engine cooling water intake to fill.
Beyond all these mechanical/physical elements to the motor install we have all the electronics and controls to sort out. We have got nearly everything for this area of the work (last battery due in a couple of months, throttle assembly due in a month). So plenty of work still to do.