3d printing technology in boat building ?

Dear All,

I was wondering about the practical use of 3d printing technology during a boat building process.

My first boat (18 feet 2 seater powerboat) is currently being designed, and I was wondering that once I have the 3d CAD files of the boat, could 3d printing technology be used to make the process faster and more cost-efficient? Printing the plug, or printing the boat itself?

The US Navy printed a submarine (made of 6 parts) out of carbon-fiber. (source: Oak Ridge release details of the U.S. military’s first 3D-printed submarine https://3dprintingindustry.com/news/oak-ridge-release-details-u-s-militarys-first-3d-printed-submarine-118738/ )

There are several big printers available on the market that could easily print the boat ( 2018's Biggest & Most Expensive 3D Printers in the World | All3DP https://all3dp.com/1/biggest-large-3d-printer-world-most-expensive/ )

Is it too early to explore the opportunities of this technology? Is it a crazy idea? Pros and cons? Any ideas, opinions are welcome...

 

There's a lot of tooling and building currently under way, there's still some bugs that need to be worked out, but it's moving along. Smaller parts are becoming more cost effective, bigger tooling needs added strength and support which adds to the cost and complexity. I'd say before too long it will become the primary way of building tooling.

 

To elaborate on what ondarvr said. Simple answer is; "yes you can".

But the "buts" are huge.

With current technology, you really can't get a useable plug/mold straight from print. Even at the finest resolution possible there are far too many printing artifacts (the lines and rough surfaces between the layers), which requires a ton of manual post processing. Sanding and filling. Same goes with even final printing of actual vessel components. Strength and lack-of-porosity, which are quite important for a boat, are not printing's strong suit. So basically you would be printing the "foam core" that you would have to go and glass and fair.

Time. 3D printing ("additive manufacture") is s. l. 0. w.... Hours and hours to produce even small parts. A useful boat, printed at a resolution that doesn't look like it belongs in "Minecraft" will literally take weeks if not months.

The two along above, means that with current systems, you could probably have drafted, jigged up, and layed up one conventionally before your printed product is done.


Even building the printer yourself, you are going to have a significant investment in money for hardware and time in getting it sorted out and working properly. Luckily, printers scale pretty well. The computery bits can be hung on a tiny desk top printer or a huge dry dock gantry sized machine with a relatively modest increase in motors and power. But they are still slow compared to other techniques, injection molding, layup molding, milling, cutting, and welding up, etc.

But, on the other hand, there are advantages. Printing can produce precision with out needing the hands-on master craftman's skill. Instead the skill turns to the tool that actually makes the product, the printer and its controlling software. If you can draw it out in CAD, you can send it to the processor which sends it to the printer. Assuming you keep the printer happy. Different technologies, different skills. Its the wave of the future. I'm sure The Machines will make great boats for themselves after they've killed us all.

 

What about modeling?

Seems like it could be a quick way to build say 1:10 scale models for tank testing, etc.

Just an idea. Experience is nada, nichts, nothing.

 

Haha, JamesG123, you must be a Skynet fan

So I've contacted some "large" 3d printer manufacturing companies, started discussions, we'll see where these will lead...

Thermwood's L-SAM system has already printed a plug, and they've used it multiple times to build moulds around it, but no further info is available of the life span of that plug, since it's made of carbon-fiber reinforced ABS, it should last. That machine has CNC capabilities aswell, so no or minimal need for manual post processing.

Very true the issue of resolution, I guess one has to find the optimal balance between resolution and printing speed, "the sweet spot", then it's possible to get an estimate about the material deposition rate and total time needed to print the project.

I'd say the most viable option for using 3d technology would be printing the plug. I'm not sure how long a 3d printed mould would last or if it would be strong enough in the first place. But sooner or later someone will just print one, and let's hope that the info about the experience will be public. The same goes for printing the boat itself. Certainly, I would entertain printing a 1:5 or 1:2 model for testing, it depends on budget and enthusiasm. Maybe I will be able to establish a cooperation and do some experimental printing with a printer manufacturer.

 

Yes modeling and "rapid prototyping" is where 3D printing shines now. That is pretty much what they are doing. Using the tool (3D printer) to make another tool (plug/mold) isn't the ideal though. Its isn't called "Additive Manufacturing" for nothing. But yeah in a mass production setting (or people that have lots of cost sunk into traditional molding skill and equipment) , you go with what works best.

At some point, the technology of both the printing process (printer) and the materials will catch up to and exceed capabilities of traditional "subtractive fabrication". Printing has already come a very long way since the first iterations back in the late 90s. The biggest real problem with printing going mainstream isn't engineering. Its that no one has successfully marketed printed objects as "superior" or "desirable" yet. As Additive Mfg. becomes more prevalent and capable, I'm sure that will happen.

 

I worked on a 36' 3D printed cat hull mold last year, currently the finished surface on a part that size is rather rough, so it needs to be built oversized and then CNC cut back down to the correct dimensions, after that a coating needs to be applied and worked for a good mold surface. This is the same process used at this time with foam, which is significantly lower in cost right now, plus the major tool builders are set up to do it this way.

But from what I've seen since then the process has been improving, but it's still not quite there yet, it'll need more refinement before it takes over as the main method of building tooling/plugs. I don't think we'll need to wait very long for the improvements that will allow smaller parts to become cost competitive.

At one time only a few large accounts could afford CNC machines to cut foam for tooling, now many of my customers have their own to build smaller plugs, the cost and complexity has been reduced to the point where even some hobbyists have their own CNC machine to cut shapes for tooling.

 

There's an old saying that goes "just because you can doesn't mean you should".... I've done a good bit of producing 3D printed parts in both metal and plastic. The bottom line is that if the part is small and complicated and can't be made easily any other way, then 3D printing is great. The bigger and more massive the part you should be looking at other methods.

3D printing is like building a sand castle on grain of sand at a time... That's fine if you're trying to build a castle that fits on a diner plate. But if you're building anything larger, the guy with a bucket and a shovel is going to beat you at getting the job done. Thin parts that don't have a mass are the best candidates. If the part is massive you're just spending time on the machine and that's expensive.

Part quality is of course a big issue. To get good part quality you have to go to very fine deposition rates, and that takes more time an money..

I don't doubt that additive manufacturing has a place and if you want one or two pieces, don't want to spend money on tooling or machining setup, or have complexity or features that you can't make any other way, then go for it. But expect that you'll spend a lot more for a part than you think because the process takes up a lot of machine time and if you're buying time on a machine that's expensive.

 

Depends on if you "own" the machine or not. As in you've either bought it yourself or have exclusive use of it. Then the big expense is already behind you (or in front of you however many years the accountants say). You've made the investment in the machine. So you actually "lose money" if your machine isn't actually doing something, anything, even if its building a sand castle one grain at a time. Because your printer can also do more than a dude with a shovel, and the printer doesn't need 8hrs of sleep, overtime, holidays, etc.

As I type this, I have a printer making replacement lampshades for my daughter's room Chimera-ish lamp o' many lamps. It takes it 13 hrs. to do each one, but I can set it and forget about it. The cost in power and filament is trivial, but I need to justify the thing to Wife, so it winds up making lots of toys and whatdoesthatlooklike? objects, just because I can.

Its getting/gotten that way in industry. Companies, esp. those who do low volumn/high value like aerospace are embracing additive because they've invested in the capacity so they are making use of it where there are same-same other fabrication methods. You don't need a shop that does Ti welding of structures and fittings from tube stock and another that does composite tank shells and overwrap if you can have a sintering metal printer that can turn out either.

And its only going to get 'better' as the technology improves and... insert your favorite Startrek replicator fantasy here. They are working on very large and very fast printers for mass production/scale fabrication. Actually doing stuff by human hand will all go into the craft niche category (optimistically), or what the 99% unemployables will have to do to get by (pessimistically).

Back OT- Except for racing, marine applications are oddly going to lag most everything else I think. Either the objects need more strength and durability than most printed products can provide, or they would need to redesign how boat fittings are shaped and used to compensate for that. And in an industry as traditional and sunk in established standards/common parts/techniques/toolings and so on and so forth, yeah, not gonna happen for a long time. If ever. But I agree that there really needs to be (more) of a business case for choosing additive other than "we can".

 

Thermwood's L-SAM system has already printed a plug, and they've used it multiple times to build moulds around it, but no further info is available of the life span of that plug, since it's made of carbon-fiber reinforced ABS, it should last. That machine has CNC capabilities aswell, so no or minimal need for manual post processing.

Don't get too excited about the carbon fiber reinforced ABS.
This is tiny length fibers.
It improves ABS, but it is typically a low volume %, and it will not come close to the carbon fiber cloth reinforced epoxy you might be thinking about.

 

While if you're a hobbyist you can buy a machine and make things, in the real world for every machine you buy you have to amortize it over a period of time. If you buy a machine that can print metal you're going to be charging the customer a lot more than $100/hr just for the machine cost.. Never mind the cost of powder, and then labor on the machine, plus non-recurring engineering time to do the setup and process engineering for each part. It doesn't take an accountant to figure out that while there cost of tooling isn't huge, the cost of time on the machine can eat you alive. Printing stuff is good if you want to produce a part with no tooling, but if you're making more than a few prototype parts it's far less expensive to tool the part and cast it with conventional technology … The cross over point for aluminum parts is about 3 or 4 pieces. That is, if you need to make 5 or more pieces you can buy tools and cast parts for about the same as printing them, and after that the costs are much lower for the conventionally produced part.

 

This was exactly my experience when I was still working.
I was doing plastic parts and the cross over was around 20 parts.
That did depend somewhat on the actual configuration of the parts.
2 years ago.

The other thing about aluminum was that you couldn't get high strength aluminum. Just something similar to 6061 (30KSI tensile strength).
But the technology seems to be moving fast.

 

Yes you get something similar to 6061T6 It's typically a bit better than casting quality, but not as good as a forging. It's fine if you aren't looking for a real high strength part. One thing that you can do with the printed part is make a wall thickness that is somewhat thinner than you can with some casting processes. For instance with a good size part you can cast down to .125 thickness in aluminum sand casting processes, and with a printed part you can make it thinner in some cases. Of course if you go an investment casting you can make the part much thinner and more complex, but that's another step up in cost...

 

Except an accountant will tell you that the machine is a sunk cost. It costs you the same if its running and making money or if its collecting dust in the corner. Most try to maximize the former. You are thinking old school where you are mostly paying a skilled machinist, the equipment is a minor cost. Printers don't operate on "machine time", they run on "output time" . Your biggest costs are the one time set-up, followed by maintenance, the rest of it is lights-out automated running for 1 hr. or 1000 hrs.

The cross-over point is really about production capacity & time. If you need a dozen widgets and have no deadline, you can have a printer chug them out at the same or better costs than conventional casting and machining (esp. if you don't have a legacy investment in those capacities and would have to build or outsource it). But if you need some arbitrary X production over Y time that would force you to buy Z printers to meet/match, which is where additive loses out to conventional methods. For now. They are rapidly getting better.

 

The experience I had said the material cost, wastage of material, operator time (minimal) and programming (including the overhead) came out to a cross over of 20/1. This was a direct comparison to injection molding via quotes by both sources. This was for pre-existing equipment on both sides with no significant implementation timeline restrictions.
In this case the $70K for injection molds was a significant part of the cost comparison.

I don't believe you are right in actual comparison (plastic).