3D printing propellers and parts

[Detroit Whitey]

Ok so some guy can make a AR-15 lower assembly and some other guy can print a human ear. Why are we as boaters not printing the parts that dreams are made of? I just got a look at the maker bot home 3d printer and if this advance in technology is not the best thing since fuel injection I don't know what is. Has anyone on here made anything yet? This is gonna be great!!!!

[BJuby]

Print me a 75H tower please :D

[Powerabout]

its great invention and I believe many are working on hard products as that is where a huge market is;
Armed forces, bag of stuff and a printer and any part is made on the front line
Aircraft, 3D printer and a bag of stuff in the hold and you have already made the part before you land, same as ships and offshore rigs

[Yellowjacket]

One word sums up 3D printing of metals.... expensive...

Making metal parts by 3d printing is very expensive. To make a 75H tower would cost you $10,000. Just because you can doesn't mean it makes sense. You could make a casting pattern by gluing together 3D printed plastic pieces and then cast the part, but the investment casting pattern would cost you cost you over $5k, and then you have to cast the part and if the casting ends up with holes or porosity in it, it is junk and you have to start over.

For making one-off research parts it makes sense and we have done parts that way, but it would be less expensive to hog something like a lower unit out of billet than it would to make it from a 3D printed metal model. Bigger stuff is tougher because you make so much of it into chips, but I would guess that making a 75H tower from a billet is about as expensive as making it from 3D printing.

We have done it in both aluminum and nickel base alloys, the nickel base alloy part was a 8 inch diameter piece that was very intricate, but it cost more than $25k!

The process pays off if you are trying to make something that you can't easily machine, or need features that you can't machine into the part because you can't get a tool in there to do it.

For instance, if you wanted to make a prop with a hollow blade, or something that you simply can't make any other way, then go for it.

For parts that are more commonly made by conventional processes, those processes are much less expensive and therefore the printed parts don't make sense.

[Powerabout]

which part of the 3d printing is expensive say doing a tower?

[omcstratos]

which part of the 3d printing is expensive say doing a tower?

For starters, I'd say the printer and the time it takes to print.

In one of my CAD classes, we used a 3d prototyping printer and it took about 3hours to print something 2"x3"x5". That was with a plastic printer

[Yellowjacket]

Volume of material = Cost and Overall Size = Cost

That is, the more volume in the part the longer it takes on the machine to make it. The overall size also comes into it because the bigger the part the more passes the machine has to make. So a bigger part with the same volume as a smaller part costs more than the smaller part. The time on the machine = cost.

Bigger parts are harder too since there are size limits to the machine. Lots of machines couldn't make a tower even if you wanted to. You would have to make it in parts and weld it together.

Right now the typical method to make something like a tower as a rapid prototype is to make it in a plastic that could be burned out of a ceramic mold. First you would make a plastic piece that was scaled up about 3% more than the final part out of special plastic. You might have to make it in several pieces and glue them together since the tanks are typically about a foot square. Then you would invest the part (mold ceramic around it), burn out the plastic, pour in aluminum and finish machine the mating surfaces and pin holes and you have a new tower..

Cheap, well no, but if you need one that's probably the easiest way to do it. The other way is to hog it out of a billet. That's expensive since the billet costs a good bit and you turn most of it into chips, but you'd have to make a model of it and get quotes on doing it to figure out what is the easiest way to make it.