3d printing technology in boat building ?

That's because you are making someone else's boat payment. Just like right now you don't ask for a single injection molding, you don't ask for 20K prints. One technology is set up for high volume mass production and the other is not, especially contractors. Its not so much that they can't, its just not in their interests to do so.

 

The injection molding tool cost $70K.
That didn't matter if you made 20 parts or 200,000.

The cheaper per part cost of an injection part paid off the tool cost is relatively short order.
That was from the cheapest shop in the local neighborhood

The per part cost of the 3D printing just went on forever. As everyone says, it is a slow process, also using expensive raw material (with plenty of waste). Actually it was treated as hazardous waste.

 

Again, square pegs and round holes. However $70K will buy you a really nice 3D printer with which you can print your parts forever for just the cost of the material*, a bit of power, and your per piece costs will chase depreciation towards zero.

What exactly were you trying to use that was considered hazmat?

* if you are making plenty of waste, you are doing additive mfg. wrong.

 

The size of the particles.
The company told me they were required to box the left over powder and ship it for hazmat disposal.
And there is plenty of powder left over.
Oh, they also said they did not reuse the unused/unsolidified powder due to inconsistency/ inclusion in the next build.

I'm not doing it. It was the largest 3D printer in the midwest.

I'm interested - what are you building in 3D?

 

Meh, they don't reuse the powder because they can charge the customer for it.

I do prototyping of seemingly random structure and objects for myself and others, and my kids. But I also do consultive work for aerospace companies that play with the big toys.

 

To each his own opinion.
If they could 1/2 the price of the parts, the break even point would shift to get them more business.
Not everything is a conspiracy.

They could actually keep the price the same and reuse the powder and make more money, no one would know the difference.

OBTW, I was an engineer with one of those aerospace companies.

 

They don't reuse the power because of liability, and lack of incentive. The mfg. told them they couldn't, because they had no incentive to design their system to dry and regrind print media, and they (both) get to make a little bit more by making the customer(s , the print vendor and you) pay a little bit more for their special eleven herbs and spices plastic powder. Sometimes you don't need a conspiracy.

Right now mass production via injection molding and casting has the majority of business because of economies of scale and simple inertia. Most decision makers in industry choose a traditional method because its what they know, or like in your example, additive isn't competitive at scale. So that leaves additive mfgers with a headwind, so they have to position their prices and capacities to go at a specific niche that can fetch the highest profit margin. That being prototyping and tricky specialty low-volume parts. And they shun the rest and that maintains the status quo.

 

Do you really think that if there was an opening for a new business based on "not following the status quo" that someone would jump on it?
There is lots of venture capital available, and lots of people who think they will be the next Apple, etc.

 

Yep. And its driving a lot of innovation in additive. I have put my money on some form of EDM being the likely "breakthru" technology. One of the problems is our patent system. 3D printing didn't really become a thing until the basic patents for the entire concept expired and then people (Makerbot etc.) could start building and selling printers. If you scroll thru the patent database you can see lots of really cool stuff, but its all tied up from the real world by the patent trolls.

 

As of now and in my opinion the best use for 3D printing for this application would be to create jigs, fixtures and specialized tools to aid in the manufacturing process.
One use that is very practical though is what they do at Scaled Composites (the composite aircraft manufacturer), they use a large foam 3D printer to create foam cores, which they then machine down to size with CNC.

 

Well la-ti-da.

Why don't you just glue up foam blocks and then CNC them.
Been done forever. Foam is not really expensive, depending on the type.

Skip the 3D printer expense.

 

You can also print with expanding spray foam (polyurethane). You could print oversize and then mill it back to precise dimensions. Of course for a plug you might as well stack and glue up rigid PU foam panels in the rough dimension and mill them back the same. But you wouldn't need too much fairing I figure? What you'd really want is a sanding robot though.

There is also a technique for 3D printing long carbon fiber strips on large airplane wings. I've seen a video with a gigantic robot arm holding and rotating an aircraft wing while a print head prints and wraps long strips of carbon fiber around the "plug" or whatever it was. That was insane, but theoretically you can use some UV hardening resin to print individual carbon or fiberglass threads or strips to surfaces. It just needs a super long and articulated 6DOF robot arm with a kind of roller. Like with those packet band rollers.

So if you could 3D print with structurally good foam you could fully 3D print a boat hull without a plug. If you could automate additive manufacturing, spray paining and sanding with one robot arm. You'd still have to flip the boat around.

Of course just the software to program these very complex robot movements and computer vision to adjust to small imperfections on the surface is super expensive to develop.

And then of course there will be 10+ parties with patents in this field that you'd have to negotiate and pay licensing fees to. So basically in 20-30 years.

You could also print small houses like this or parts of houses like this. Obviously this really only makes sense for unique designs.

 

So is this all just fantasy, or is there something working now?

Your carbon fiber example is properly called tape placement or filament winding - been around for at least 20 years. Not with UV cure resin as far as I know.

What would be the point of 3D printing foam oversized, then spending the money to NC machine? Again for at least 20 years foam blocks have been NC'd to make tools or parts. Foam is relatively cheap. If you added the expense of 3D printing instead of using foam blocks before NC'ing you probably wouldn't have a cost effective method.

One thing I was taught about 3D is that not all materials are appropriate candidates, because the typical process requires some specific (and very limiting) physical properties of the material. One such is the time it takes for the material to solidify. Too slow or too fast doesn't currently work.

So - do you have examples that work?

 

I'd call it sci-fi, not fantasy OP asked if you could 3D print the boat itself, and theoretically it's possible. Of course you're right, gluing up and milling blocks seems to be the way to go.

Thanks for letting me know the correct the name for tape placement. The advantage there would be that you could optimize the orientation of each fiber for optimum strength. Again just theoretically because it would be a very tricky optimization problem to solve for a computer.

The advantage of foam printing would be zero personal labour and a small saving in materials. It's not an important advantage, but there is a patent and a video demonstrating the idea. This can also be used to 3D print forms to pour concrete for house building and also add insulation.

The advantage of the PU foam is that it's already used for spray foam insulation and can be set to cure very fast and you can change the density and strength with the composition.

 

Unfortunately tape placement is pretty expensive unless you have a part which is ideal for the process. You practically cannot vary the placement of each fiber tape (or tow), due to geometric limits of both the tape, the machine, and the part.
At best the optimization is somewhat approximate.
And I have an example hollow strut or tube on my desk which was done by tow placement, which was only 40% more expensive than hand laying.

Sorry to be such a nit picker, but real technical processes and advancement depends upon getting all the details right.

Overselling the attraction of a process just leads lots of people into a dead end, or into being a victim of those who just want to sell something, no matter if it really is a benefit.

On the other hand, I would really like to see useful examples of new technology.

Sci-fi is still wishfull thinking (but my favorite reading genre).