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3D metal printing

Wlodek

Aluminum
Joined
Nov 15, 2018
I am following this topic for the last few years and could use a system in my shop...if the price, size and operating cost (all preferably on the smaller scale :)) and specifications are right. This will be for mostly small parts in the medical devices field, mostly stainless and mostly complex shapes that the printing will defeat the purpose if there there is too much work to cut the support, polish and do other finishing later.
So far none of the systems offered seems right on all those accounts. But a few days ago, talking to a colleague, I was surprised to find out that there is actually a company in my area (in Vancouver, BC, Canada) that just came out with a system that might be exactly what I want:

Metal 3D Printer - Rapidia

The system will be shown in the RAPID + TCT 2019 conference in Detroit from May 20th to 23rd, but I hope to see it locally before this. If so I'll report - can be of interest to all in my position.
 
I'd have questions about the density of the final sintered product, any dimensional changes after sintering, and its material properties when the bonding materials were boiled and burnt out .
 
It sounds interesting, but as already pointed out, make sure the dimensional accuracy after sintering, and porosity/density will meet your requirements. I believe the MarkForge metal printer works in a similar fashion.
 
Desktop Metal uses a 3-step process based on "metal injection molding": print, debind, sinter.

This system appears to use a different type of binder to go straight from print to sinter, eliminating the middle step that involves chemical waste.

This won't have any effect on finishing requirements. A sintered part is still going to have a finish similar to that of a fine casting.

If you want to go straight to finished part, look at the Matsuura Lumex machines. These alternate between printing and milling on each layer to achieve the desired result. Price on the smaller model is close to a million USD.
 
Desktop Metal uses a 3-step process based on "metal injection molding": print, debind, sinter.

This system appears to use a different type of binder to go straight from print to sinter, eliminating the middle step that involves chemical waste.

This won't have any effect on finishing requirements. A sintered part is still going to have a finish similar to that of a fine casting.

If you want to go straight to finished part, look at the Matsuura Lumex machines. These alternate between printing and milling on each layer to achieve the desired result. Price on the smaller model is close to a million USD.


I've arranged to see the system at the plant next week and will go to Vancouver (over three hour trip each way)to get more info and, hopefully, to see the operation and results. From the short phone conversion I got the impression that the system is not that expensive (certainly not into millions...)
I like the idea that the parts need no debinding and can be brushed with water to get a smooth (smoother?) finish.
 
Full disclosure: I know several of the Rapidia people quite well including the founder. First price: I understand it's aiming at the Markforged price range which is like $140-$170K very roughly. The interesting thing with this machine is by simplifying the debind step it's overall way more compact than the others in this category in terms of the actual floor space required. I think for example it's the only one of these that would physically fit in our very space-limited shop for example.

By the way, this whole "aimed at the medical device market" is a bunch of malarkey but that's an argument for another day. Hopefully Implemex will chime in here and take a big bite out of a reality sandwich on this topic.
 
Full disclosure: I know several of the Rapidia people quite well including the founder. First price: I understand it's aiming at the Markforged price range which is like $140-$170K very roughly. The interesting thing with this machine is by simplifying the debind step it's overall way more compact than the others in this category in terms of the actual floor space required. I think for example it's the only one of these that would physically fit in our very space-limited shop for example.

By the way, this whole "aimed at the medical device market" is a bunch of malarkey but that's an argument for another day. Hopefully Implemex will chime in here and take a big bite out of a reality sandwich on this topic.

I agree with you that there is quite a lot of hype regarding 3D metal printing for the medical market...as indeed in the whole area of 3D printing in general. But despite the hype and the many unrealistic and exaggerated claims, the process offers some advantages not easily possible in other ways. Currently I am doing some small, complex parts by high resolution 3D printed patterns in wax and investment casting. I think some of those, especially where accuracy and surface finish are less critical, can be directly printed in metal, with the advantages of the process that are not possible in casting; for example internal lattices. Like any emerging technology, additive metal forming process will find eventually its legitimate place.
 
I am far from being a expert on this method. Where I used to work has a 3D printer that uses metal dust and then uses a laser to melt the dust to a solid. No sintering required.

Tom
 
I agree with you that there is quite a lot of hype regarding 3D metal printing for the medical market...as indeed in the whole area of 3D printing in general. But despite the hype and the many unrealistic and exaggerated claims, the process offers some advantages not easily possible in other ways. Currently I am doing some small, complex parts by high resolution 3D printed patterns in wax and investment casting. I think some of those, especially where accuracy and surface finish are less critical, can be directly printed in metal, with the advantages of the process that are not possible in casting; for example internal lattices. Like any emerging technology, additive metal forming process will find eventually its legitimate place.

For most of the potential applications I've come across, surface finish would be an issue. One area where you are happy with some roughness is where a part is supposed to bind to bone, such as hip and femoral head replacement parts. But these are rather niche applications with established market players versus the number of devices and components that need to be as smooth as practicable for sterilization reasons. My friend just went to the Sauber (now Alfa Romeo) F1 team headquarters in Switzerland and they apparently do a number of 3D printed parts, seemingly because they can get the internal lattices for parts like the roll hoops. I found this interesting because F1 car production is probably a perfect niche right now where they need to make small numbers of parts, but definitely not unit quantities, and they need good strength to weight ratios. One other thing as one considers actually buying a system, for many applications you are going to want to print and then machine some features, as with traditional castings. So you ideally have a fancy five axis CNC machine before you get the fancy metal printer. We actually are in such a position with the CNC machine in place so I'd be lying if I told you I wasn't scheming how to get $$$ for this....
 
Without sharing any confidential information, can you suggest the types of parts you are involved in that require internal lattices and structures? I've been struggling to imagine good examples in this area that make sense. My concerns have been along the lines of parts that can't be inspected, that need to be; Like parts with internal lattices. One metal 3D printer keeps using a motorcycle brake or clutch lever as an example of the perfect part for internal lattices, and this seems like a good example for a racing bike, but for critical parts beyond that, I don't yet see proper examples, jet engines aside (Leap fuel nozzle, and titanium blades with integral passageways for cooling, both by GE)


I agree with you that there is quite a lot of hype regarding 3D metal printing for the medical market...as indeed in the whole area of 3D printing in general. But despite the hype and the many unrealistic and exaggerated claims, the process offers some advantages not easily possible in other ways. Currently I am doing some small, complex parts by high resolution 3D printed patterns in wax and investment casting. I think some of those, especially where accuracy and surface finish are less critical, can be directly printed in metal, with the advantages of the process that are not possible in casting; for example internal lattices. Like any emerging technology, additive metal forming process will find eventually its legitimate place.
 
I've seen lattice designs for the aerospace industry utilizing DMLS technology, and the demand is going up. I work in the industry of additive manufacturing, while we are working towards getting AS9100 to do these kind of prints, our competitors are getting a lot of aerospace business. Other than that though most of our business does not involve any sort of lattice optimization, aside from printing samples because lattice structures look awesome.
 
I recently attended a technology preview of the Desktop Metal Studio system,
budget around $250k for a printer/washout/scinter combination
benefit of the MIM filament based option, is that overall material costs and strength can be exactly where you want, parts can be changed rapidly without long lead times, and material is purchased as rods and additive instead of solid blocks of raw material with 90% going to the chip bin, with long cycle times.
my summary video is here, including a section on the sintered part pre and post sintering. post sintering, the part was finish ground to a dimension (as you would with a sand or investment cast part)the claimed porosity is significantly better than cast parts, from 85% to 98% material density.
they claim to have taken the dimensional shrinkage parameters into consideration, so you model your finished part, they enlarge to accommodate shrinkage, provide a custom sintering profile and tell you which parts to place and where in the oven, to ensure consistent repeatable results. Same with the wax binder washout step, it calculates wash profile to remove one of the 2 binders prior to sintering.
Having dealt with sales peoples claims and the inevitable gap to delivered product performance, I would be suggesting for critical dimensions you would include a machining allowance and post-process with surface grinding or other milling operations.
the time factor of 90% finished parts without the massive waste from solid blocks would be one benefit, where geometries provide raw material requirements that are costly.
in their presentation they suggest parts 3D printed on DMS are cost competitive for runs up to 180,000 parts when compared to MIM injection moulding, and with far superior change lead times, re-run of spares as needed etc.
the possibility for expansion suggests that 1 wash and 1 sintering unit would support an additional printer, so the marginal cost to double output is significantly less. extending to 5 printers, 2 wash stations and 3 ovens or something like that, significantly benefitting the marginal cost model.
Desktop Metal Studio examples
 
I recently attended a technology preview of the Desktop Metal Studio system,
budget around $250k for a printer/washout/scinter combination
benefit of the MIM filament based option, is that overall material costs and strength can be exactly where you want, parts can be changed rapidly without long lead times, and material is purchased as rods and additive instead of solid blocks of raw material with 90% going to the chip bin, with long cycle times.
my summary video is here, including a section on the sintered part pre and post sintering. post sintering, the part was finish ground to a dimension (as you would with a sand or investment cast part)the claimed porosity is significantly better than cast parts, from 85% to 98% material density.
they claim to have taken the dimensional shrinkage parameters into consideration, so you model your finished part, they enlarge to accommodate shrinkage, provide a custom sintering profile and tell you which parts to place and where in the oven, to ensure consistent repeatable results. Same with the wax binder washout step, it calculates wash profile to remove one of the 2 binders prior to sintering.
Having dealt with sales peoples claims and the inevitable gap to delivered product performance, I would be suggesting for critical dimensions you would include a machining allowance and post-process with surface grinding or other milling operations.
the time factor of 90% finished parts without the massive waste from solid blocks would be one benefit, where geometries provide raw material requirements that are costly.
in their presentation they suggest parts 3D printed on DMS are cost competitive for runs up to 180,000 parts when compared to MIM injection moulding, and with far superior change lead times, re-run of spares as needed etc.
the possibility for expansion suggests that 1 wash and 1 sintering unit would support an additional printer, so the marginal cost to double output is significantly less. extending to 5 printers, 2 wash stations and 3 ovens or something like that, significantly benefitting the marginal cost model.
Desktop Metal Studio examples


I'd like to buy a Line Break, Pat.
 
At the last IMTS show I spent a 1/2 day visiting the 3 D booths and was fascinated with this new technology that will revolution how not only plastic but metal parts will be made in the future. I signed up for this magazine. It should have the info your looking for. We saw cheap Chinese made table tops selling for $6000.00 and saw 100'long many millions of dollar photo's of others they make airplane wings on. Industry News | 3D Metal Printing Magazine
 
I am following this topic for the last few years and could use a system in my shop...if the price, size and operating cost (all preferably on the smaller scale :)) and specifications are right. This will be for mostly small parts in the medical devices field, mostly stainless and mostly complex shapes that the printing will defeat the purpose if there there is too much work to cut the support, polish and do other finishing later.
So far none of the systems offered seems right on all those accounts. But a few days ago, talking to a colleague, I was surprised to find out that there is actually a company in my area (in Vancouver, BC, Canada) that just came out with a system that might be exactly what I want:

Metal 3D Printer - Rapidia

The system will be shown in the RAPID + TCT 2019 conference in Detroit from May 20th to 23rd, but I hope to see it locally before this. If so I'll report - can be of interest to all in my position.

From my research and talks with experts in this field, it all comes down to what is your intention and performing a feasibility analysis. Im presuming these parts are to form part of implants? If so, I would not skimp on a metal AM machine. The top of the range machines are high cost for a reason. These machine provide significantly better results and you get the support of the machine manufacturer's experts to qualify, calibrate and maintain the machine. All of which are critical for your certification in the medical industry.
 
There is an interesting material for stainless steel 3D printing made by BASF. After printing, the item is sent in to the vendor and gets sintered. I have never done this process, but am tempted to try it, as I have a MakerBot Method X with the Labs2 extruder that is capable of doing metal. The drawbacks include small size (the sintering oven input is limited to 10cm cubes per order/batch) and questionable dimensional accuracy. The manufacturer recommends upsizing 20% in axes x and y and 26 % in axis z. I bet there is some sizable variability in this "error" depending on geometry.
 
There is an interesting material for stainless steel 3D printing made by BASF. After printing, the item is sent in to the vendor and gets sintered. I have never done this process, but am tempted to try it, as I have a MakerBot Method X with the Labs2 extruder that is capable of doing metal. The drawbacks include small size (the sintering oven input is limited to 10cm cubes per order/batch) and questionable dimensional accuracy. The manufacturer recommends upsizing 20% in axes x and y and 26 % in axis z. I bet there is some sizable variability in this "error" depending on geometry.

That's cool that the filament is compatible with the desktop printers. Please share your results if you try it. Stainless is obviously quite high temp, but I wonder if lower temp metals / alloys can be processed that way at home. So like bronze or aluminum can be baked in an electric heat treat/forge oven.
 
That's cool that the filament is compatible with the desktop printers. Please share your results if you try it. Stainless is obviously quite high temp, but I wonder if lower temp metals / alloys can be processed that way at home. So like bronze or aluminum can be baked in an electric heat treat/forge oven.

If you want to do any of this at home, you'll still need a chemical debinder, in addition to the furnace.

Powder Metallurgy - Sintering Temperatures for Some Common Metals

Aluminum sinters around 600C or 1100F. Common aluminum alloys wouldn't be very strong coming out of the furnace because they age harden at much lower temperatures, around 400F.

The aluminum powders available for DMLS machines appear to be the high silicon variety to achieve good strength straight out of the printer.
 








 
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