Well, some things work and some don't.
Got the supplied bow thruster installed and (with some improvements), it works fine.
Also installed the Pitot tube on the bow for the pressure sensor that reports back the speed through the water.
All the PCBs are ordered, so they should be here in the next 10 days.
So.... this &*%# crane.
I knew it wasn't well designed. I have watched several videos of other peoples cranes operating and its jerky and very unrealistic.
The gearbox that drives the rotation is sweet. That works very well and is lovely and smooth.
The problem is the boom lift. The plans show a (horrible) arrangement of another winch that pulls a 0.3mm steel wire down a 1mm tube that lives inside the 6mm tube that rotates the crane.
This thin steel wire then attaches to the top of the crane boom. This is the design issue. Due to the pivot point for the boom being so close to the end, the wire only needs to pull 5mm or so to raise the boom up to it's full height.
This also requires some considerable pulling, as the you are lifting the entire boom (not to mention anything you pick up) with an incredibly short amount of leverage.
I abandoned the winch they suggest, as I don't have room for yet another winch, and an entire winch for 5mm of cable pull seemed mad.
So, I tried a small 10g servo. It does work, but its super jerky and really doesn't have the ability to lift much. Mainly because the cable stretches under any load, and once you are over the initial weight of the boom lifting, it suddenly gets lighter and springs up.
Plus, with the winch rope also going up the centre of the crane tube, its all a bit of a horror show to install.
Rethink time.
I have a very small geared motor. I could possibly add this to the actual crane to control the lifting mechanism. I am not worried about the aesthetics of the crane, I don't mind a bit of free licence if it makes it work better.
This would need power, so I might have to add a set of brushes to the rotary plate to allow that to work. Not ideal.
The crane only actually rotates 270 degrees. You could probably just disguise the motor cables as hydraulic hoses.
The other option is to leave the servo under the deck, and try lifting the boom with a cam instead. A full sweep of a servo wit h a cam would significantly increase it's lifting ability.
Hmm