Hello Lew.
You are quite correct about the heat and ABS. I don't have an enclosure so my models are subject to cold draughts and temperature fluctuations. Any large models I have made warp and often come apart along the layer lines. I would prefer to print in ABS or try one of the other filaments, it's just that in my situation PLA+ seems more forgiving.
Like you I would prefer to use wood or metal but I am not skilled enough to made small things out of metal. When I was in my twenties I got my hands crushed in a glue spreading machine and lost part of my left hand and also feeling. I have had skin grafts, muscle grafts, nerve grafts and bone grafts. the only thing I haven't had is a total body transplant. A circular saw took away part of a finger on my left hand and to make matters worse about 10 years ago a cat bit me on the first finger on my right hand causing sepsis and the loss of part of that finger. The surgeons at the hospital wanted to amputate part of my hand to stop the infection. I refused to let them .Anything that I am able to make I consider a bonus. With regard to spot welding with the pen, my prefered method is to melt a hole in the plastic and immediately squirt molten plastic into the hole. Anyway To all who are reading this, Good luck and keep up the good work.
best wishes Tim

Hello AlessandroSPQR,
The model sub came from Thingiverse, the man who did the original work also produced a U-boat as well. I enlarged the model and added a bit of detail. The internal watertight container is also on Thingiverse. On Cgtrader someone called Flared phoenix has much more detailed stl. files for sale. With regard to the canon on Sir Kay, the german AA gun and the oerlikon were commercial files bought for a few pounds. Anyone interested in 3D printing and model boats, should visit Thingiverse, Cults, Cgtrader and perhaps Printables. Thingiverse files are all free, some are excellent others are not.
Best wishes to all
Tim

Hi Tim, first of all, congratulations on creating a model entirely with a 3D printer.

You've brilliantly solved the size issue (size of the model relative to the maximum size of the largest piece the 3D printer can produce). It may seem easy and obvious, but it's not.
Is the design your own, or did you obtain it from a third party, like the cannons you showed us?

Thanks for the information on PLA and ABS; I agree with what I learned before working with 3D printers.
I asked for a lot of details about the capabilities and durability of these materials. I agree with you about ABS, I wouldn't recommend it.
However, I'm not a fan of PLA either. Neither material convinces me.

I've printed and had printed many pieces in both ABS and PLA, but in the end, I've decided never to use 3D printer products for important and critical parts, subject to mechanical stress or stress, subjected to heat, or requiring long-term durability.

I had a bad experience with the funmel. I had designed it and had it printed. I left it in a wooden tool shed for a few months before assembling it. When I was ready to attach it, I noticed it had warped. Unfortunately, I don't remember if it was made of ABS or PLA.
I discarded it and made the new funmel out of three materials (aluminum, plastic, and wood). I don't have a PC with me, but as soon as I can, I'll attach photos so you can see the notable difference.

The cannons I designed and had printed by a friend of mine (after many attempts and tests with other 3D printers) could have been made out of brass. I should have used a milling cutter (which I don't have). Brass would certainly have looked better, but I would have had excessive weight above the waterline, which would be absolutely unacceptable for the lateral stability of the model.
So I have to point out a point in favor of the 3D printer in this case.

...also, can't say that I just have a thing for 3D printing. Right now I'm in the woodworking mode.

Lew

Nick, some thoughts on the use of 3D pen for welding ABS

Keep in mind that when the filament is streaming out of the nozzle, the bed and eventually the print is constantly heated to a high temperature so the filament will fuse to print.

The pen's heat is usually sufficient enough to heat the filament enough for it to extrude and stick to freshly placed thin filament but probably not to a cooled part that has some mass to it.

A better way, although I haven't tried it, might be to use a soldering iron with a long point and use some unextruded filament as a welding rod. Let me know if anyone has tried this.

Lew

Hello Tim, good conversation. I don't have much of a concern about ABS. All of my models never see any extended time outdoors. Even my most frequently used ones will get only an hour or two in our "Florida sunshine" every two weeks. Even at meets when out of the water at meets they are in the shade. Otherwise they are in my AC home. Seldom have heat on.

My Wiesel schnellboot is over 50 years old and still seems strong. Almost all of my ABS parts are painted. I did make a compartment for my auto about 6 years ago. It sees a good amount of sun and is holding up well (unpainted). Perhaps it is the thickness. Very thin ABS might be the issue.

My ABS props are holding up pretty good after frequent runs in the pond. So I guess that my successful field testing of ABS means I will be using it until something better comes along.

One more item, ABS can warp because of the type of printer used. A large, unenclosed printer can cause this because of the uneven application of heat. I use a smaller, enclosed printer.

Lew

Hi Tim.
Looks good. I was looking at a 3D printed sub at a model boat show. It was being sold by a small company for about £90 (?) and to be honest it wasn't any better than yours or as long. I have never tried ABS because as I understand it, you need a well ventilated room due to the noxious fumes etc.. After trying many filaments, I have fallen in love with ELEGOO Rapid PLA+. Like you I am in my 70's (73) and love trying new things. Anything to do with engineering keeps me happy 😁

Hello SimpleSailor,

I thought you might be interested in something that that I am experimenting with. It is a T class sub from WWII. It has been printed in PLA+ and is about 7ft long (2 metres). I made it in 6inch sections (15 cms) and stuck them together by spot welding them with a very cheap 3D pen. So far it is hanging around in the garage and been dropped from height, kicked and generally abused, so for it has not been damaged. I printed it quickly with quite thick layer settings which is why the layers are so obvious. I am going to plate it with something to represent the welded plates. Maybe even coat it with resin or paint and sand it down. The watertight container is a length of drain pipe with 3D printed and laser cut sections and end caps, rather like the Robbe sub.
Lew, just a thought but ABS breaks down under sunlight, is hygroscopic and to some extent is biodegradable. I have ABS hulls that I have bought years ago and they are now so brittle, they crack when touched. All plastics and resins have a limited lifespan. There is no perfect plastic you just find the one that suits you. I built this sub originally with ABS but after about 4 sections the sub was so horribly distorted and cracked because of cold weather and draughts which caused uneven shrinkage. Maybe the climate where you are suits ABS better. I work in a very cold garage and PLA+ just suits my environment better.Like Nick the Steam I am in my seventies, I don't expect my models to last longer than me. I build them for pleasure. Anyway good luck to you.
Fellow ship builders please don't judge the quality of the sub as it is a quick experiment. I have enjoyed reading all the comments made about 3D printing, its pros and cons.
Best wishes Tim

Hi Nick. I have a cheap pen on order. Going to give it a try. It's not for all joints, just where a fillet weld could go. Will post the outcome when the pen eventually arrives from China.. 😁

Simple Sailor, I have not tried using a 3D pen but here are the pitfalls as I see them. First, there is a chance dimensions could be altered, you wouldn't be able squish the filament down to zero thickness, using a solvent avoids this. By the time you have laid down a layer from the pen as "glue" it would have hardened enough to prevent it sticking to the part you are trying to glue too. It could possibly work by using proper welding techniques, ie allow for a fillet welding then build up with the pen and hope it sticks properly. As stated before, I have not tried using a 3D pen the above missal is just my thoughts on the subject....