Whoa! Propellers are a serious 3D proposition! Not least as you can't have a threaded prop/shaft. Well, you could but it would be rat shit. Shall have to think about that one. I'm speaking from the design perspective, of course. The Machine does what it's told to do.
Everything is feasible. You have to realise the constraints of the system though. My printer has a maximum build volume of around 200x200x200 mm which is generous in the home printer category. Many are much smaller. So, to get a model of any size, you might have to cut it into blocks which are glued together after printing.
If you don't have access to a 3D printer, it might be worth your while checking whether their is a local Maker space you can join. They will almost certainly have a 3D printer you can borrow and are likely to also have laser cutting, metal turning and milling, and a host of other facilities normally outside the pocket of the average modeller. We are just starting up our Maker space in Guernsey but to find out if you have one near you, check www.nesta.org.uk/uk-makerspace-data.
Hmm. Deja vu. I didn't miss the point. It's more that the point was poorly made. You don't rely on people to do everything for you except make the hull, draw the plans, etc etc. So the original statement was silly. I too am a pensioner with the obvious limited financial resources. I just have a 3D printer which I use for many purposes. So, you don't have the skills to use one. That's no big deal, I can't dance or juggle but still get along OK. The thread is about 3D printing and shouldn't be rat-holed because you don't have access to a printer.
That's a fair comment but you could say the same about buying a pre-moulded hull or a kit. But, take it to its logical conclusion, do you fabricate your own plywood? Cultivate, and harvest your own balsa wood/bass wood/mahogany? Be a purist if that's what you want but is it right to sneer at others who find their own path to tread?
Reprap is practically the industry standard for 3D printing. It doesn't say how large the print volume is, the Ultimaker is around 200 x 200 x 200 mm. The picture is difficult to read but it doesn't look as if it has a heated build plate in which case, you are going to need an enclosure of some sort to keep drafts out to avoid your prints warping. You can't argue with the price, though.
As a post post script regarding your comment concerning printing parts to make the machine better. This is probably the case with most printers in this sort of price range but it's not arduous and, if you design the parts yourself using something like OpenSCAD then you you know that you have really earned that whisky nightcap.
As a post script, Cura allows you to print direct from your PC via a USB cable (supplied with the printer) or to write the GCode to an SD card which slots into the printer and from which you can select the file to print.
I wasn't sure that the Ultimaker original+ is still available but I just checked and it is at 995 Euros. It comes as a flat-pack with all the necessary pieces and, with mine, a free spool of filament. The frame is made from high quality ply wood and the quality and accuracy of the laser cutting is astonishing although you might need to ease a few of the joints with sand paper for a not too snug fit. I sealed my frame with cellulose dope floor a quick-dry finish. The electronics and stepper motors are easy to fit as is the setting up of the transmission components although the latter are a bit fiddly. All in all, it was good fun building the beast. Printing with it is easy, you download the Cura program which will build your G-Code files from an STL file and allow you to set up the printing parameters for the job. I've had a few disasters but generally get good results with PLA printed at 205 degrees with a bed temperature of 50 degrees. I've found PLA from Rigid Ink gives the best results but, to be honest, I haven't exactly 'played the field's with filament providers. One point in favour of Rigid Ink is that, once you are on their email distribution list, they will send you hints and tips for printing which is a boon as Ultimaker don't provide a pilot's operating hand book or much further reading on it. Would I get another one? Probably, yes.
I've been using a 3D printer for 18 months now. Very useful for printing things like ship's wheels, bollards, etc. Thingiverse is a useful resource although, these days, every other design seems to be for a fidget spinner - very yawn inspiring. I design much of the stuff I print with OpensCAD, an open source (free) application but it helps to have a bit of computer programming experience to use it effectively.
As I recall from my material science studies, a resin coat on its own will strengthen a thin wood panel but it is prone to cracking. Once it has cracked to a certain extent, any strength it has imparted will have evaporated and all you are left with is extra weight. Glass fibres added to the resin act to prevent cracks propagating through the material and add to its toughness. So resin adds strength, glass fibre adds toughness.
Sorry to be pedantic but I do like to be specific. Counter rotating props will always be turning inwards whichever direction they turn. I am assuming (!) that turning inwards in this context means that, seen from aft looking forward, the port screw is turning clockwise and the starboard screw is turning anti-clockwise. Correct or no?
I always use lightweight glass fabric. I have tried model airplane tissue, horticultural fleece and just about anything else that could possibly be a cheap solution. Nothing works like glass fabric though. I find Deluxe Materials is the handiest source for me.
Ha ha! I once crossed the road in Munich without using the pedestrian crossing and had a rolled umbrella waggled at me by an elderly lady for being a bad example fur die junge leute. They do love their rules in Bavaria.
I find Eze-Kote from Deluxe materials a much better material to work with than epoxy or polyester. It's a water-based resin which provides a waterproof and fuel-proof finish. you may need three or four coats but that's not a chore as it's easy to apply, there's no wastage as the pot never 'goes-off' and it's dry to a paint-able surface in half an hour. You clean up with water as well.