Sure, we don't have flying cars or hoverboards (yet), but there's still plenty of proof that we're living in the future.
Case in point: Porsche has found out how to add 30 horsepower to a 911 GT2 RS by 3D-printing its pistons.
Reportedly weighing 10 percent less than their forged…
Perhaps they can 3D print some IMS bearings that live.
I can't wait until metal 3D printing becomes somewhat affordable. Even the smaller ones still cost about the same as a new BMW.
looking at the picture they are not "ready to use" when they come out of the printer ,
I wonder what the time is to CNC them from a forged slug compared to printing and finished machining ?
Much less with the 3D printing, probably. Forgings generally have a lot of excess to be removed. I'm used to more industrial forgings than performance vehicles though
californiamilleghia said:looking at the picture they are not "ready to use" when they come out of the printer ,
I wonder what the time is to CNC them from a forged slug compared to printing and finished machining ?
Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
californiamilleghia said:looking at the picture they are not "ready to use" when they come out of the printer ,
I wonder what the time is to CNC them from a forged slug compared to printing and finished machining ?
this is the big part left unanswered. they show a shiney machined OD and top which is not the case. post processing is required to get the pistons to where they are now.
rodknock said:I can't wait until metal 3D printing becomes somewhat affordable. Even the smaller ones still cost about the same as a new BMW.
Having seen these printers in action, I think speed is the key.
In the time it would take to print one piston, a conventional forging method could probably do hundreds. Engine plants make over 1000 engines every single day- and average of 6 cyl (even 4/6/8 production) that's 6000 pistons a day for one plant. Call it 24 hour production- that's just over 4 pistons per min made.
Some huge advancements would have to be made for that 3d printed pistons are a reasonable way to make pistons for the masses.
Pete. (l33t FS) said:californiamilleghia said:looking at the picture they are not "ready to use" when they come out of the printer ,
I wonder what the time is to CNC them from a forged slug compared to printing and finished machining ?
Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
Diesel guys can forge two halves and then friction weld them together with some pretty quick production speed, but that also requires post-machining like the printed ones.
Pete. (l33t FS) said:Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
I don't think they could be cast either. The hollow jacket could not be formed either way. I think the only 'traditional' method to make something like that would be to assemble a multi-piece piston.
ProDarwin said:Pete. (l33t FS) said:Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
I don't think they could be cast either. The hollow jacket could not be formed either way. I think the only 'traditional' method to make something like that would be to assemble a multi-piece piston.
No idea who uses it, but there is a patent on using a molded salt ring during the casting process. The salt is then dissolved out afterwards, leaving the cooling gallery.
In reply to Pete. (l33t FS) :
That's what lead Koenigsegg to develop and utilize 3D printing for manifolds less than a decade ago. It's crazy that it's now at a Porsche pricepoint. It honestly means that within the next 10-15 years, if not sooner, it'll be the production norm.
All I can think of is a 4age or KL series motor fitted with lighter, more efficient 3D printed pistons with better thermal tolerances. Let alone if Lexus were to decide to implement and test the development of the technology in creating a second generation LFA.
And we haven't even gotten to it's practical uses in suspension arm applications yet.
I've read up on 3D metal printing and it sounds like there are issues getting uniform metal layers. Like there are pockets of different grain structure inside the metal. That sounds like a bad thing in a piston?
cyow5 said:ProDarwin said:Pete. (l33t FS) said:Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
I don't think they could be cast either. The hollow jacket could not be formed either way. I think the only 'traditional' method to make something like that would be to assemble a multi-piece piston.
No idea who uses it, but there is a patent on using a molded salt ring during the casting process. The salt is then dissolved out afterwards, leaving the cooling gallery.
IIRC the 6.7 Cummins uses something like that.
And when the operator lets the oil changes go and it sludges up inside the piston, the crown melts down. They NEED the piston cooling to function.
Pete. (l33t FS) said:cyow5 said:ProDarwin said:Pete. (l33t FS) said:Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
I don't think they could be cast either. The hollow jacket could not be formed either way. I think the only 'traditional' method to make something like that would be to assemble a multi-piece piston.
No idea who uses it, but there is a patent on using a molded salt ring during the casting process. The salt is then dissolved out afterwards, leaving the cooling gallery.
IIRC the 6.7 Cummins uses something like that.
And when the operator lets the oil changes go and it sludges up inside the piston, the crown melts down. They NEED the piston cooling to function.
Yep, that's why oil galleries in general can be problematic on production vehicles. The gradual crud build-up reduce the cooling effectiveness until ka-blooey. The friction-welded approach I mentioned also produces protrusions into the cooling channel (although there are also patents that help), and this can pose problems down the line, too.
Cool!
rodknock said:I can't wait until metal 3D printing becomes somewhat affordable.
It's called skill with a MIG welder.
ProDarwin said:Pete. (l33t FS) said:Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
I don't think they could be cast either. The hollow jacket could not be formed either way. I think the only 'traditional' method to make something like that would be to assemble a multi-piece piston.
Is it Turbo to want more out of life?
these specific parts due to their internal geometries cannot be produced another method, this is how you use additive manufacturing correctly whereas normally someone wants you to copy something with the technology then complains about the cost.
Not just pistons.........
fidelity101 (Forum Supporter) said:ProDarwin said:Pete. (l33t FS) said:Given that it sounds like they have a hollow cooling jacket under the crown, I'm going to guess the design can't be forged, just cast, if traditional manufacturing processes were to be used.
I don't think they could be cast either. The hollow jacket could not be formed either way. I think the only 'traditional' method to make something like that would be to assemble a multi-piece piston.
Is it Turbo to want more out of life?
these specific parts due to their internal geometries cannot be produced another method, this is how you use additive manufacturing correctly whereas normally someone wants you to copy something with the technology then complains about the cost.
Well, you could make any of these designs another way, they might just be painfully expensive to do. You could machine layers and weld them together, etc.
Agreed, doing geometry that is otherwise way to complex/expensive is a great use. OR for prototyping or production runs of very low numbers - that's what I use it for.
And yes, a connecting rod is a great place to do it. Make a box section instead of an I beam...
Can you imagine the number of forelorn, old/odd engines this now can return to working order? Like old flatheads especially with their awful bores (looking at you, Buick straight 8!) and huge lug pistons could now chop literal POUNDS of rotating mass out of the engine. This could lead to some wild stuff if the cost comes down to our hobbyist level.
buzzboy said:I've read up on 3D metal printing and it sounds like there are issues getting uniform metal layers. Like there are pockets of different grain structure inside the metal. That sounds like a bad thing in a piston?
I'd think that post process heat treating would solve that.
Mr_Asa said:buzzboy said:I've read up on 3D metal printing and it sounds like there are issues getting uniform metal layers. Like there are pockets of different grain structure inside the metal. That sounds like a bad thing in a piston?
I'd think that post process heat treating would solve that.
Heat treating can help a little bit with cleaning up the grain structure but it can't do everything. Most heat treatments are designed to either temper brittle phases, manipulate precipitation hardening alloys, or add surface treatments. It's nearly impossible to add anisotropy or grain recrystallization to a structure, which are the main benefits to forging.
The process that Porsche is using is better than most 3D metal printing, it uses a high powered laser to sinter metal powder together to build layers. Cheaper metal printers (ones that cost less than a house) use a metalized polymer filament, then remove the polymers with chemicals, then sinter everything in an oven leaving a very uniform structure throughout though not necessarily a strong one. The laser sintering printers let you somewhat manipulate the grain structure throughout the part, as well as giving you some localized alloying control with some setups, they also have much finer resolution for greater dimensional control (on the order of ~50 micrometers for the really high end printers). This comes at a buy-in on the order of $1,000,000 or so (and up, of course).
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