3d printing and casting molds

[Mitchg07261995]

I was at the antique store the other day and the shop owner gave me free plans for a roughly 1:12 scale cordless type steam engine. Most of the parts I can make on my lathe, others I'll need to employ my neighbor (also a machinist) to help me make some other parts that are to large for my mini lathe, and for the parts that need milled. My question is, that I know many of the parts will need to be sand casted, and I was wondering if it was possible to 3d print the parts so I can use them as molds to shape the sand so I can cast the real parts out of aluminum. Is this possible?

 

[Cogsy]

If you can draw the parts up properly then you can 3D print them and sand cast from them. Depending on the part, you may need to make 1 piece or 2 piece molds. You'll also have to allow for shrinkage and add draft into the molds so you can remove them from the sand.

Depending on your skills, it may turn out to be quicker to make patterns out of wood, but there's no reason 3D printing won't work.

 

[aonemarine]

Yes you certainly may print the patterns for casting. I recommend using the wood filled filament from colorfabb as it is easy to sand and finish.

 

[Jasonb]

Depending on the part you may not even need to cast it, you can get away with quite a bit by fabrication

casting or pile of metal?

 

[Mitchg07261995]

Thank you very much for the help and very quick responses. It definitely looks like some of the prints will be made from a few separate peices. The base for the engine is 22.375"Long and 11.250" wide
Most of the parts to be casted from iron, and I don't have the supplies to cast at home, so I'll have to see if anyone around town might be able to help

 

[kadora]

Hello
aonemarine quality of 3D printed parts on your picture above are amazing.
Are they already sanded or they are just printed.
How many 3D parts has /probably a frame/ on your picture.
thank you

 

[aonemarine]

I think i had sanded the a frames, but the base is as printed. The wood filled filament prints very well and sands very easily which makes it great for making patterns for sand casting, but it does not burn out clean for investment casting. For investment casting i use regular pla plastic which burns out clean and is great for rapid prototypes.

 

[Tin Falcon]

that T rex is beautiful got to hold it in hand a couple times last weekend.
Tin

 

[ProfX]

I have one question, how much can a metal 3d printer can substitute the sand casting?

Can I already print functional engine blocks and crankshafts?

 

[Tin Falcon]

I have one question, how much can a metal 3d printer can substitute the sand casting?

Can I already print functional engine blocks and crankshafts?

According to news reports NASA GE and universities are printing functional metal parts.
I have also seen news reports stating jewelry is being 3d printed some nay be but i know some is 3d printed wax patterns that are investment cast.
Dave and others are using fdm printing to produce a plastic (PLA) pattern to produce metal parts via investment casting.

A functional engine block certainly could be made with this method. Some machining required.
as for a crank shaft less likely you would need to get pretty hot to cast steel . not impossible but not as easy as casting aluminum or bronze.
Tin

 

[LongRat]

It is indeed possible to print functional parts directly in metal.
Developing and selling such machines is my day job. Currently most of them are going to healthcare users (dental/medical implants etc), with aerospace and automotive companies also using them. For high precision parts with fine surface finishes, you would need some postprocessing just as you would from a casting. However, in most metals the printed parts will be likely to outperform a cast counterpart. You have better control over the internal structure, reduced chances of porosity and no contaminants. We can get titanium parts VERY close in mechanical performance to wrought bar stock.

 

[ProfX]

According to news reports NASA GE and universities are printing functional metal parts.
I have also seen news reports stating jewelry is being 3d printed some nay be but i know some is 3d printed wax patterns that are investment cast.
Dave and others are using fdm printing to produce a plastic (PLA) pattern to produce metal parts via investment casting.

A functional engine block certainly could be made with this method. Some machining required.
as for a crank shaft less likely you would need to get pretty hot to cast steel . not impossible but not as easy as casting aluminum or bronze.
Tin

I'm aware that NASA and others are already printing some metal functional pieces, but I don't know exactly what kind of metals they use and how accessible is the technology.

 

[ProfX]

It is indeed possible to print functional parts directly in metal.
Developing and selling such machines is my day job. Currently most of them are going to healthcare users (dental/medical implants etc), with aerospace and automotive companies also using them. For high precision parts with fine surface finishes, you would need some postprocessing just as you would from a casting. However, in most metals the printed parts will be likely to outperform a cast counterpart. You have better control over the internal structure, reduced chances of porosity and no contaminants. We can get titanium parts VERY close in mechanical performance to wrought bar stock.

How big can you make a part out of 3d printed titanium?
I guess it is pretty expensive to make something ordinary out of it.

 

[LongRat]

Our machines have a 250 x 250 x 350mm build volume. Current materials are titanium (6Al4V alloy or pure Ti), aluminium, several steels, inconel, cobalt-chromium alloy. It isn't a cheap process, like everything it isn't suited to every part. Realistically it isn't economically feasible to make model engine parts, but I dream of a multi cylinder engine block with internal cooling and oil passages all built in-situ

 

[aonemarine]

Our machines have a 250 x 250 x 350mm build volume. Current materials are titanium (6Al4V alloy or pure Ti), aluminium, several steels, inconel, cobalt-chromium alloy. It isn't a cheap process, like everything it isn't suited to every part. Realistically it isn't economically feasible to make model engine parts, but I dream of a multi cylinder engine block with internal cooling and oil passages all built in-situ

And thats why I keep playing with the home 3d printers and investment casting.
Im learning more and more what works and what doesnt, as well as different approaches and processes to get the results im looking for...

 

[ProfX]

Our machines have a 250 x 250 x 350mm build volume. Current materials are titanium (6Al4V alloy or pure Ti), aluminium, several steels, inconel, cobalt-chromium alloy. It isn't a cheap process, like everything it isn't suited to every part. Realistically it isn't economically feasible to make model engine parts, but I dream of a multi cylinder engine block with internal cooling and oil passages all built in-situ

Cool!!! I didn't knew it was already that far!!!

I also dream about printing my on engine, specially because I like the crazy one's

But considering that the cost of a prototype engine on the OEMs is over 200k (or something like that) I wander how far more till it is viable to start printing these prototype engines...

 

[kvom]

There's a company that prints sand. Saw a fellow on Chaski forum who had his loco drivers printed in sand+resin and had castings made from them.

 

[ProfX]

So apparently you can already print Torlon!! More known as for being the material used to build the plastic engine on the 80s. It has very high mechanical properties and can withstand high temperatures.

So many possibilities are available, and so little money...

I think it would be possible to print 90% of a model engine, it would probably not be cheap, but you would be the first...
Anyone interested?

 

[Holt]

For some years I have been earning my living by laserwelding broken parts for plastic injection moulds, The factory I work at is placed a few hundred meters from the main mould factory at the LEGO company in Billund Denmark, so I have done a lot of welding at there moulding parts. a few years ago, they started making steel inserts by "3D printing" and I have had the opportunity to weld in such inserts, you can't tell the difference in that steel and other tool steels, but they can't make the surface directly usable, it have to be milled or EMD eroded at the surface. The great benefit is that complicated cooling channels can be made while printing the parts, I haven't seen such inserts for quite some time, perhaps it's too expensive compared to the benefits.
The process of printing steel parts as I have been told should be like this: you start with a baseplate, a thin layer of steel powder is applied, and a laserbeam is melting the powder where the part is wanted, a new layer is applied etc. etc. all is done in a closed area without oxygen, probably with some sort of Argon, that's what I am using for the laser welder.


Holt