I'm a bit disappointed with the lack of quality of the Caldercraft fittings. How hard can it be to make these
Yeah, well. All in all they don't look so bad, it's just with these couple of bigger (and mechanically important) parts, maybe I just had an unlucky batch. However, there are some other, um, difficulties, of which I will tell you in a minute.
With things like the keel extension as shown above I prefer to use the supplied fitting as a pattern and fabricate a copy in something more robust such as brass. I also discard things like immensely heavy white metal rudders and fabricate a replacement in brass with stuck on plywood or metal strip detail.
Thank you for your input (and for your immensely helpful review from back when which I frequently refer to
).
I agree that the keel extension may benefit from a replacement and I already ordered some stuff to give it a try. I ordered a piece of brass and a needle roller bearing for the rudder axle. I'm not sure whether I'll come up with something useful with that stuff, but in case of failure I still have the original parts.I don't see the problem with the rudder blade and in fact like the heavy build of that thing. I bought a couple of high torque servos anyway, so this shouldn't be an issue as long as it runs smoothly in its supports.
As for the drive shaft support A-frames - they are all over the place, shape-wise. When I first tentatively mounted them, there was a difference of approx. 6 mm when measured from the stern. This will not do.
I mounted them onto a piece of scrap wood, carefully warmed them with a hair dryer to make the metal a bit soft and then carefully, softly bent it like Beckham (see image below).
I proceeded likewise for the other A-frame, albeit in the opposite direction.
After two rounds of re-mounting, measuring and more bending, they were almost spot-on, if slightly bent. But that's the price I have to pay to have the propellers in perfect symmetry
I then tentatively mounted the rudder support plate and determined the place for the upper hole in the hull. Difficult place to drill since it's slanting and so close to the vertical part of the keel. I used an extended Dremel drill to bore a pilot hole and then drilled from the other (upper) side downwards. The result was perfect, I'm glad (and prowd) to report
Caldercraft fail intermezzo: the rudder parts bag came with a note (see below):
Important: Rudder tube is now BRASS. What they failed to mention, however, is that said rudder tube also
doesn't fit the rudder shaft. It simply doesn't. Because it is too small. The rudder shaft is 5,0 mm in diameter and the rudder tube, which, important, is now in brass, only has 4,8 mm inner diameter
Off to the hardware store I went to buy an appropriate 5,0 mm id brass tube which actually fits the rudder shaft.
So if you're about to build the Imara yourself, you may want to double check the inner diameter of your supplied rudder tube.
In the picture below you can see the rudder, the supplied and the home made rudder tube. Note the slightly different sizes.
After I had this little nuisance out of the way I had to manufacture a wooden support for the upper part of the rudder tube since this part no longer seems to be part of the kit (it used to be a white metal part, but I've read other building blogs where they also noted that this part was MIA. No big deal. A wooden block is presumably more solid, anyway.
After I had everything in place (and in the right size), I shortened the screws for the drive shaft supports accordingly and glue-screwed them in place. Likewise the rudder tube and its wooden support. The epoxy is hardening as I type this
The white metal parts are now coated with white primer, in case you wonder.
Next step will be mounting the drive shafts and aligning them with the steam engine...