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[Tworrs]

Dom, if I may make a suggestion for sealing your portholes, perhaps very carefully applied clear bathroom silicone sealant may do the job?
Garry

[Tafelspitz]

Brilliant suggestion, Garry!
That should do the trick 

[Tworrs]

I hope it does Dom, good luck.
Garry

[Tafelspitz]

While working on the hull, I noticed a small section at the bow where the ABS wall was incredibly thin - like paper thin - so I decided to reinforce that part with some glass fiber and resin.
The hull seems to be a bit surprised, judging from its facial expression 

Dom

[Tafelspitz]

Nose job  I ended up not using silicone sealant (nor any other glue or glue like sealants) for the portholes. They're just too friggin' tiny to work with and after wasting a whole pack of them I eventually went down a different route.
I stuck them down flat on the ground on a piece of sticky tape and gave them a couple coats of clear glossy varnish. This ended up very neatly sealing the gaps between the glass and the brass rim while keeping the windows perfectly clear and shiny.

After thus being treated and successfully standing the water tank dip test over night, they were now ready to be glued into place.I gave the inside of the nose and bow a coat of black primer followed by a coat of Vallejo "dull aluminium" to prevent the light from shining through the plastic. I've learned that lesson the hard way during the Imara build  The wooden pallet that I meant to go inside the nose ended up being too high up for the part of the bow that sticks inside the nose part and touching the LED I placed there, so I had to take it out again.

One LED is fitted inside the nose and one inside the bow. Anxious about water from getting into the hull by way of the front porthole somehow, I added a small bow bulkhead for good measure. This also serves as holder for the front porthole illumination LED.It's a bit messy and a blob of GFK filler somehow ended up down at the bottom of the bow unnoticed, but fortunately it is not disrupting anything.
Lighting is designed for 6.0V (vs. 3.3V in my Imara).
And yes, I know I'm not there yet. There's obviously still some more sanding, re-filling and re-sanding necessary 

[Tafelspitz]

Next up: rudder linkage. The kit came with a couple of very thin and flimsy linkage levers that I'm sure will break if you as much as only look at them, so I designed and printed a bunch myself to my own specifications. And while I had the CAD and printer fired up, I also made a servo cradle. Printed from black tough PLA for some added strength and durability but without going overboard 

[Tworrs]

That observation module looks amazing Dom, great job.
The printed parts definitely look more substantial than the supplied parts, makes me lust after a printer 
Garry

[derekwarner]

Very tidy Dom    ....did the internal splines for the servo drive shaft print with dimensional correctness?..........


[I assumed they would universal, however Google tells m the M6 toothed spline can be 21T, 24T or 25T  ]

Derek

[Tafelspitz]

Thank you guys!
Derek, the servo horn you see there is an original part that came with the servo.I only printed the levers for the rudder.
Not sure how well those tiny splines would print, anyway. I know for a fact that working M6 threads print OK, but any smaller than that, I don't know. Maybe with a finer nozzle. Anyhow, there's no need for that as I do have the original servo horns (and a couple of spare ones lying around) 
Dom

[Tafelspitz]

This is now where those tiny thread cutters from an earlier post came in handy 
I cut the M2.0 mm threads for the rudder linkage which will eventually look something like this.

[Tafelspitz]

Seeing all those electronic parts and wires lying on the table before me is a little bit intimidating and overwhelming, I must admit. There isn't too much space inside this hull, really. But once put inside everything starts to fall into place and I have already a good idea what to put where.
I'll have to make a DC/DC-board again for all the different voltages I need:
- Main motors will run on the native 7.2 battery power.
- Bow thruster 12V (step-up converter)
- Lights will run on 6V- Steam 5V with a miniature speed controller that will run parallel to the main ESC
- There's also going to be a radar motor and perhaps a couple of tiny motors driving the heli rotors that require 3V or less, but I'll be feeding them via resistors if necessary.
Initially I was thinking about a sound board as well, but I'm not going to bother after all. Too much going on already 

[Tafelspitz]

Buliding and soldering the DC/DC - board. I have three voltage regulators that convert the native battery voltage (7.3V) into 5V, 6V, and 12V.6V is for lights, 12V for the bow thruster. Main ESC will run off native voltage, as will the smoke generator.
The 5V is for nothing in particular yet, but I added it for Justin 
I finally gave in and ordered another ShockWave 3 sound module from Model Sounds Inc. Cost me an arm and a leg what with shipping and customs duty  but I like the one in my Imara and also wanted one for this build. It has CAT3408 twin diesel engine sound on one channel and an assortment of horns, bells, dings and some other clips on the second channel.This one uses a small exciter instead of a speaker to save on space and weight.



While uploading the images of the DC/DC-board, I just noticed that I forgot to sand the wooden base plate. Tsk.   

[Martin (Admin)]

 
https://www.modelsoundsinc.com/index.php

[Tafelspitz]

That’s the one, Martin.


Dom

[Tafelspitz]

The sound module just came in. Along with a detailed manual 

[Tafelspitz]

Just a small picture update. Lots of innards for such a small vessel  I made a XT60 connection socket for easy battery replacement and a support stand for the sound module. Wiring is not complete and it will be tidied up a bit. I guess 
Dom

[Colin Bishop]

Yes, a lot of innards. Are you still happy with the stability of the boat under wind and water conditions? I'm building a paddle steamer model at the moment and have to be very careful not to accumulate unwanted top weight.

Colin

[Capt Podge]

This is my first look at this blog and I'm amazed at how you electronics wizards manage to get things working as they should.
Now, I'll have to go back to the beginning of your build and read it properly.
Look forward to seeing your progress Dom - cheers!


Ray.

[Tafelspitz]

Thank you for checking in, guys!

Been away for a couple of weeks but now slowly getting back to it.
Colin, I have yet to put her in the test tank for the first time but I guess this is going to be one of my next tasks after I have all the wires in place and tidied up a bit.
Cheers, Dom

[Tafelspitz]

Hey folks.I ran into a bit of a problem dry test running the main motors. There is quite a bit of strain from the sealed Raboesch shafts on these little motors - I figure they need some running in, but the starboard shaft also showed some considerable vibration that I didn't like. I don't know where it comes from. Switching the two shafts didn't make a difference, so I figure it's not a bend in one of the shafts. Replacing the cardans with double navy cardans to reduce some possible aligning inaccuracies came to mind - the same ones I'm using for the steam engines in my Imara. I'm very happy with them.Problem is: they are 7mm longer than the single cardans and on top of that, they require 4 mm shafts on either side. The motor shafts, on the other hand, are only 2.3 mm  To account for the longer cardans, I had to completely re-design and re-print the motor supports.

I also designed and printed some tiny adaptor insert prototypes for the motor side of the cardans. They're working well but I'm gonna need these machined from brass eventually. Alas, I don't have a lathe. Any idea whether such tiny parts can be machined at all? Outer diameter is 4 mm, inner diameter 2.3 mm and there is a 3 mm hole for the grub screw that grabs onto the motor shaft...

Anyway, this whole alteration brought some relief, but the Raboesch shafts still are a bit stiff. I hope this will ease out over time, once the seals are run in a bit.

[Colin Bishop]

Are the Raboesch shafts stiff to the touch when disconnected from the motors?

The vibration could be down to the couplings, those red ones sare not always drilled true.

Colin

[Tafelspitz]

Are the Raboesch shafts stiff to the touch when disconnected from the motors?

Yes, they are a tad stiff due to the seals. I've read elsewhere that this is an issue that will get better after some running. Maybe I'm gonna lube them with a drop of glycerine, see if that makes things a tad better.

The vibration could be down to the couplings, those red ones sare not always drilled true.

You may be on to something there, Colin. That would at least explain my observations.
That's also why I need these motor drive shaft inserts precision machined. I'll have to find a place that can make them for me.
CheersDom

[Tafelspitz]

I finally managed to machine a couple of adaptor inserts for the double cardans. The fine folks from a FabLab MakerSpace let me use their lathe last saturday and there was even an expert showing me the ropes. 
After some milling, drilling, reaming, sanding and polishing, they turned out and fit very well. Very tiny parts but now I can finally go forward with the build.

[Colin Bishop]

Just noticed a You Tube video about Calypso.

https://www.youtube.com/watch?v=bKL1HTM0ij0

Colin

[derekwarner]

Hullo Dom......if you are chasing vibrations, so a few assumptions 


1. this appears to be a brass spacer, but what does it do? ..........apart from providing a mass that potentially cause vibration.....even with a reamed bore onto the propshaft, the clearance between the two will allow for an off axis twist between diameters when the grub screw is tightened
Depending on the physical distance, a piece of tight-fitting shim [of the same thickness] forced [red arrows] between the elements will ensure optimum axis when tightening the grubscrew

2. the motor shaft bush....we see as reamed verticall by hand ....so there is a potential for an off-axis bore, when pressed  into the coupling hub

Could the motors be moved aft to eliminate the brass rotating spacers?
Could a one piece coupling hub be produced, to eliminate the spacer?
-------------------
Just, from left of Field........did the original vessel design have  converging prop shafts?

Derek