Hi Chris, pleased you can see the pics again..! And thanks for the comments.
A few updates, and a bit of a close call to report...
1. Water Inlet has been fitted, I cut out the mahogany layer of planking to make the brass plate flush, and lined the cut out with epoxy to seal it. I think I'll use silicone sealant when the inlet is finally fitted to get a watertight seal... I've added a 2mm ply layer on the inside and glassed it in so it should be strong enough in the event the fitting takes any knocks.
2. Props have been drilled to take 3mm grub screws with conical ends, so they lock the props to the shafts, I'll keep the locknut too to make sure the props don't go anywhere..! I drilled the props while on the shafts so the drill cut a 'cone' into the shaft threads for the grub screw to locate in.
3. I've fixed the prop tubes and shafts into the hull... The motors, mounts, thrust bocks and prop tube have been taken apart and put together at optimal alignment, so they become one piece of hardware. The black shapes are 3d printed wedges that go under the mounts to get correct shaft angle.
I then fitted the motors to their mounted positions and enlarged the cut out where the tubes exit the hull, so there was no interference from the hull on the tubes, to keep alignment. I then fitted the P brackets into their recesses and inserted the shafts. Happily they all lined up as expected.
I poured epoxy with a syringe to fit the P brackets, they're also held by two 4mm SS bolts each.
So at this point all was well... And I masked the tubes passing through the hull before adding epoxy resin and glass tape to seal the tubes in:
Maybe some explanation required for the tubes as they pass through the hull. The main prop tubes are 9mm OD, there's a 40mm end piece of 10mm OD (9mm ID, silver soldered on) that provides a housing for the bearing at the end of the tube. Then the brass you see in the above pic is 11mm OD (10mm ID), these are cut to provide a more aesthetic pass through of the tubes, also to reinforce the area of the cut out... So all the brass tubes are an interference fit together and either silver soldered or epoxied together.
And now onto the problem. I turned the hull over and started to add resin / tape around the tubes and into the slots.
The shafts, P brackets and rudders are held in those ply slots / cases (stringers..?) to I wanted resin above and below the tubes to seal and hold them firm, which I did.
And I left the boat overnight.
Next morning resin was well on it's way to being solid. I'd left the shafts in place to ensure alignment wile the epoxy took hold... I took one of the shafts out no trouble, but the second was absolutely solid. You know that feeling when you realise you've screwed up... Resin had dripped onto the shaft past the masking tape, then run down the shaft, into the now firmly attached P bracket. Not good, not good at all.
I ended up standing the hull on end and soaking the P bracket in acetone to soften the resin, then had to grip the shaft with a mole wrench and gently start to get some movement of the shaft... Plenty of acetone and coaxing of the shaft later, I have got it out. The P bracket bearing needs replacing, the shaft needed some attention to get rid of the grip marks. So disaster avoided, and kicking myself for not masking properly.
I now need to trim up around the pass through area on the outside of the hull and will post some pics.
I've added some threaded inserts inside the hull that allow ply covers to be attached over the prop tubes, will retain the electronics boxes, and hold down the battery covers.
That's it for now.
Very best regards to all.
David.
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Topic: 1/5 Riva Aquarama... (Read 73774 times)