3D printing in metals

[Vixen]

This is a new topic dedicated to 3DP metal printing mainly by outside commercial firms

3D printing has been around for a long time and many of us have our own printer at home. Home brewed filament printing is useful but has it's limitations. There are now a growing number of commercial outfits who offer high precision laser based 3DP printing in both plastics and metals, at competitive prices. The range of printable metals and the quality of the printed items is improving every day and prices are dropping.

There are some model engine parts which are difficult (approaching impossible) to make by traditional methods. For example, thin wall exhaust manifolds (headers) and pipework. I chose to explore the 3DP printed metal route rather than attempt a difficult fabrication. I designed each of the parts in 2D CAD, that's all I have available. Petertha kindly converted my 2D drawings into 3D models and from the 3D models provided me with the .STL printing files.

Almost all of the 3DP printing firms offer an instant quote service: upload a .STL file, select a material and your required quantity, within minutes they send back a price. You can explore all the different materials for comparisons. But beware, not all commercial printers stick with their initial quote, some reassess their quote when you show an interest in ordering some prints.

My current preferred supplier is   ProtoTi.com   based in Hong Kong. They held to their instant on-line quote. I was very impressed with their prices and service. I placed an order for these parts to be laser printed in Aluminium just before Christmas. 10 days later, a small parcel was delivered to my doorstep containing, a pair of exhaust headers, a pair of coolant pipes and the crankcase breather pipe. Wow, that's impressive by any stretch of the imagination.   






The coolant and vent pipes have a very thin wall thickness of only 0.8mm whereas the exhaust pipe wall is a little thicker at 1.2mm. All the pipes printed perfectly. They were bead blasted by ProtoTi to produce a casting like appearance. The laser printed aluminium appears to be fused (melted) into one homogeneous part which needs little or no further machine work.





I did notice a slight warping at the ends of long slender exhaust pipes, probably due to cooling after the laser melting process. I guess, a sacrificial bar across the ends of the four flanges would help prevent this movement.

Overall I am very impressed with the quality and service provided by ProtoTI. 10 days from order to delivery, all for $37 plus $15 for delivery. I will certainly use them again.


Below you can see the coolant pipes and crankcase vent pipes threading their way across the top side of the engine. The side view shows the exhaust manifold loosely in place. There is a slight interference between the rear engine mounting block and the rearmost wiggly down pipe. A few strokes of a file on the engine mount block will sort that out.






That's all for this visit to Vixen's Den

Cheers   

Mike

[Jasonb]

Your pipes are looking good Mike. If you were doing it again would you have used this method for those parts you made the moulds and waxes for and farmed out the investment casting? I bet it would be cheaper.

I also had a similar turn around with parts ordered just before Xmas arriving in 10days. As I only needed the one item I played with the minimum job cost on the instant quote and got six for the ame price as one. Parts arrived Monday and I've just finished the engine.

I would not want to do a whole engine this way as I still enjoy the machining both manual and CNC but treated just like another tool it can be used when it is the most suitable for the job in hand.

[Vixen]

Jason

Back in December 1997, when I did all the pattern making, molds and waxes for the Jupiter engine, 3DP was not an available option. The investment casting cost for one inlet manifold was £25 each.

I think we can safely say that 3DP metal printing has come of age and costs are spiraling down, Each of the W165 exhaust headers cost only $11 each. The coolant pipes only $3 each. 3DP produces a part equal to any investment casting in terms of looks and quality. Furthermore, going directly from 3D CAD to finished printed part cuts out so many steps (and risks) associated with the investment casting route. I think investment casting is effectively dead.

What can you say about the machine-ability, strength and thread holding capacity of your 3DP parts. Is it similar to stock materials? I believe you have machined S316 and aluminium printed parts. The reason I ask, is because of the bad experience I had with the aluminium casting for my Westbury Seal. The cast aluminium engine block was so weak and soft that the cylinder head studs ripped out of the casting. That was the first and only casting I have ever used to build an engine, every other engine was made from stock materials of known strength and quality.

Mike

[petertha]

As I told Mike, I'm super happy with the outcome & pleased to have contributed a tiny part of this project. I agree 3DP metal appears to be a game changer. I suspect the 917 snake pit would be much the same except more. Having a full 3D model from the get-go is a big advantage. Once the pipe paths are known in 3D space, its not particularly difficult loft pipe sections along them. The slightly tricky bit here was the starting point, working from 2D Front & Side views of original drawing file to derive the path around silhouette obstructions, maintaining clearances etc. I'm not into CNC but I'm still shocked at how far Mike has pushed 2D-CAD & 2.5D-CNC on this engine to the results you see. That requires old school mental visualization of finished parts from 2D sections. A few niggly issues importing 2D format drawings into a 3D app, but most of this was just learning the nuances. I have already put those new found skills into my bag of tricks.

Interesting things can happen in the area when pipes 'come together' in the Siamese/manifold area from their various orientations. In this 4-pipe case the convergence occurred on one plane which makes cleaner sections. But resultant internal sharp corners or thin features may result & the printers may have a final say with their tools / constraints. A different engine with a different bowl of spaghetti may incur different challenges, all part of the model engineering fun. For CAD nerds, I found it better to model the entire manifold in solid including the varied fillet 'welds', then 'shell' the solid header from open ends to prescribed wall thickness. If that operation doesn't fail, its a good sign you have a compliant solid. I want to point out another nice Mike touch, the variable chamfer on the flanges like the FS.

This could go on & on. One could add extra boss material on all the welds & hand carve what end up looking like FS welds with its slight irregularities & surface imperfections. (I suppose could be modelled in 3D too, but that would require some noodling). Same goes for upsets or collars where pipes were nestled or joined even if cosmetic. Some FS pipes look to be made from straight + curve sections, mitered, welded, yes hammer massaged. So to be faithful to the FS, the CAD model should use similar geometry even though its tempting to make flowy spline curves. Obviously regular plastic 3DP parts could be made more locally to confirm things beforehand. I suppose, like casting, it may be beneficial to add sacrificial material here in there in certain areas if distortion is a fact of life, but that is trickier to assess until the parts are delivered. Well, that's enough CAD talk, lets enjoy the engine build on the home stretch.

[Jasonb]

The 316 stainles sparts only had through holes so I can't say what it would take a thread like but drilling seemed very similar to solid needing more pressure on the quill handle than say a free cutting mild steel.

The aluminium I have just had done again is mostly through holes though the air/exhaust was tapped M4 x 0.5 but the pipe connector does not put much load onto the thread so hard to say what the pull out strength is. Printed holes did come out a bit undersize eg the shank of a  2.7mm drill fitted a 3mm CAD hole.

[steamer]

I'm not worried about modeling the pipes
.just making them.

Dave

[Vixen]

Thanks for all your inputs.

I would like to move all this 3DP discussion from the W165 build log into a more appropriate 3DP topic. Can anyone suggest the best existing topic name to use?

Mike

[Jasonb]

Additive Machining would be my suggestion.

[Vixen]

The 316 stainles sparts only had through holes so I can't say what it would take a thread like but drilling seemed very similar to solid needing more pressure on the quill handle than say a free cutting mild steel.

The aluminium I have just had done again is mostly through holes though the air/exhaust was tapped M4 x 0.5 but the pipe connector does not put much load onto the thread so hard to say what the pull out strength is. Printed holes did come out a bit undersize eg the shank of a  2.7mm drill fitted a 3mm CAD hole.

On my next order (or one of yours?) we could get have them print a test coupon in aluminium and S316. (say 6mm diameter by 50mm long) We could then drill and tap it, turn and mill it, bash and bend it to get a fuller understanding of the mechanical properties of the various printed materials compared to equivalent bar stock.

Mike

[Admiral_dk]

Lovely result for those Headers etc. 

Wonder if Future 3D Prints should have a little more Meat on the Flanges (or other strategic places) so they could be sanded, filed or milled to fully flatness @ the Gasket Interface 

I remember some of my old thoughts from some years back during another Hike yesterday .... and wondered if that could solve one of your other Problems Mike ...?

So I have just sketched it in Alibre - here you see both Parts Cut in Half (for illustration).
It is basically a Punch and Die Tool. You put a length of precision ground Steel in the Die - Heat the part above the Die to between Red and White Hot. Put the Punch down over the Die and give it a Bloody good wack with a Hammer.

The Precision Ground part (the Valve Stem) should hopefully still be straight and perfectly round as before and the Hot Part should have been converted into the Valve Head.

I haven't included any Ejector or other specific Improvements (that might be needed) as this is only a 'Thought in the Air' - that you or others can play with and see if we can make the Creation of (Poppet) Valves a lot Easier in slightly bigger quantities 

Per                 

ps   Happy New Year Everybody 

[Jasonb]

I have allowed a "machining allowance" on the prints much like you would for a casting pattern. Not such an issue for parts like Mike's manifold but for rotating and sliding surfaces it is a must.

[vtsteam]

In consideration of exhaust flow, what is the internal surface finish like on 3DP mfd. small bore U shaped bent pipe?

Do they use supports in there and if so how are they cleaned out?

[Vixen]

In consideration of exhaust flow, what is the internal surface finish like on 3DP mfd. small bore U shaped bent pipe?

Do they use supports in there and if so how are they cleaned out?

Hello Steve,

Photographing the inside of a model exhaust manifold is not the easiest of things to do.





However you should be able to see the internal surfaces and mitered edges are sharp and crisp, almost as smooth as the external surfaces. However, the outside has had the benefit of bead blasting, unlike the insides. Metal 3DP printing is achieved by a laser selectively melting a bed of aluminium powder, the compacted powder provides the support during printing.

Hope this helps

Mike

[vtsteam]

Thank you Mike!    That does help. And Just to get an idea of the scale of the photos, what is the diameter of that pipe?

[GordonL]

Is it practical to do something like a flywheel at 6" to 8" diameter?

[Vixen]

Thank you Mike!    That does help. And Just to get an idea of the scale of the photos, what is the diameter of that pipe?

Hello Steve,
The exhaust pipes are all 11mm OD and 8.6mm ID with 1.2mm wall thickness.

Cheers   

Mike:

[Jasonb]

You could do a flywheel in Stainless so you have some decent weight and that would also suit a bare metal rim.

Cost may be high so an alternative may be to combine a printed spoke pattern with a rim cut from thick wall steel tube

I just tried it with a Stuart 7" flywheel which would cost you £71.00 from stuarts inc delivery. 3D printed in 316 Stainless would be £74.00 delivered so about the same

[Vixen]

Is it practical to do something like a flywheel at 6" to 8" diameter?

It would be practical to print something 6" to 8" diameter in any of the available metals. Aluminium, steel and Stainless are the most common. Brass and bronze is also available from a limited number of 3D print firms. You pay for the amount of metal powder consumed, not the complexity of the shape. Most do an instant quote so you can see what you are letting yourself in for. Jason has just posted some cost comparisons.

A 6" to 8" flywheel spinning at speed will produce significant centrifugal (bursting) force. I would question (check) the suitability of 3DP Laser melted/ fused metal with your chosen 3DP print firm. They will know all about the mechanical properties of their bulk printed metals. I believe you would be safer (maybe cheaper) making your flywheel from round bar stock or a good quality casting.

Mike

[AlexS]

Great parts been printed Mike!

[Jasonb]

I was thinking steam engine flywheels when I said they would be OK to print as those are more likely to be where printing is an advantage to forming fancy spoke patterns so speed is not going to be great. Probably get spun faster in the lathe to clean up the rim than it will eventually run on an engine.

Higher speed IC engine flywheels may want a bit more thought about strength but they do tend to be less fancy so more suited to cutting from solid. The built up printed inner and solid rim would again help keep things together. The other thing is that you would need to be making a large IC engine to get upto 8" diameter. Hit and miss or other old style engines would be that sort of size but speed is not going to be that high on those compared to a straight six or V8.

[AVTUR]

Mike

Other than ProtoTi, what friendly printers are there?

AVTUR

[Jasonb]

I use Craftcloud3d.com who are German based but the quotes come up from all over the world and posted from source. China are usually the cheapest, Hong Kong mid point and Europe the most expensive.

Interestingly I have had stuff done by ProtoTi but they came from China

Edit ProtoTi are in Shenzhen in China, photos from their website match those on the link from Craftcloud

[Vixen]

Hello John,

There are literally hundreds of firms offering laser 3DP. Ask Goggle

Laser 3DP in plastic materials is a well established industrial service, rows of expensive top end printers row after row. Fill them with powder, upload the .STP file and the machine does the rest. Now they have added dedicated metal printers to the row, the process remains much the same.

Jason uses a clearing house called  Craftcloud3d.com  They search the world for the best (lowest ?) quote. China is often the most competitively priced. I went direct to   ProtoTi.com  because I heard they had a good, reliable reputation.

Mike (AVGAS)

[AVTUR]

Mike & Jason

Many thanks. I will take a good look over the next few days.

AVTUR

[Jasonb]

The question of thread pull out was raised earlier. As I said I had not used many threads that are under load but took this video today.

The thread is metric fine M4 x 0.5. The male thread in the chuck approx 3mm long so 0.75D engagement length, Hole was drilled 3.5mm. The two chucks weigh 10.7kg, if someone wants to work out the loading I'd be happy to hear the value. BTW the part was printed on it's side just like in the video so the forces are pulling the layers apart.

<a href="https://www.youtube.com/watch?v=zSeL2acqw5A" target="_blank">http://www.youtube.com/watch?v=zSeL2acqw5A</a>

[petertha]

From Gemini The Fibber. Sorry, I wish there was a convenient way to just paste it's text, but doesn't seem to cooperate with its formatting so here are screen grabs. I'm not sure if the printers publish strength values but anyway this is what Gemini had to say.

[Vixen]

The Mercedes W165 exhaust headers demonstrate that CNC machining dimensional accuracy and 3DP printing dimensional accuracy to be very similar.

Aluminium parts (AlSi10Mg) parts from 3D printing will be stronger but less ductile than an equivalent wrought aluminium. I was therefore a little concerned that the lower ductility could cause problems with straightening the post printing warp (bend) in the exhaust pipes. However, I found the  typical elongation to failure values for As-printed AlSi10Mg were typically ~4-6% in the worst direction, due to grain structure. The slight bending I applied to correct the warp is comfortably within these limits.   

Cheers

Mike

[Jasonb]

Thanks Peter, though the part was Aluminium not steel and the threads cut not part of the print.

Mike I'm not so sure about dimensional accuracy being the same for CNC & 3DP.

The holes in that part were all 7-10% undersize. eg 3mm hole came out at 2.7mm, 4mm hole between 3.6 and 3.7mm.

The base was drawn at 28 x 17 but measures 28.23 x 17.16. Possibly more had it not been blasted.

I can do a lot better than that with my CNC or manual machines.

[Vixen]

Hello Jason,

Interesting dimensional observation.

All the through holes in my parts were undersize and had to be opened with a clearance drill. The metal felt hard, crisp and granular, quite unlike bar stock.

My dimensional observations were based on the 16 exhaust flange holes lining up perfectly with the 16 pre-machined flange holes in the cylinder head. OK, I only fitted bolts to the outside row, cos I ran out of screws.

It could be that the laser melting process adds a little to the outside and inside of the printed part, hence oversize base and undersize holes. However, I found the actual hole positions to be good.

We need more than our two samples to fully understand 3DP.

Lifting a 10.7KG lump with just 3mm engagement of a M4 x 0,5 (fine) thread in the 3DP aluminium was impressive. I will have few concerns about the strength of tapped holes in 3DP aluminium. From what we have both found regarding hole size, a printed thread would probably need to be chased with a hand tap anyway.

Cheers

Mike

[petertha]

Thanks Peter, though the part was Aluminium not steel and the threads cut not part of the print.

Thanks, I missed that aluminum detail in my query, which makes the 3DP strength all the more impressive.
Regarding the cut vs printed threads, I understood that's what you did, but I wasn't quite sure what Gemini was getting at. Maybe print roughness is not providing the same finished thread seat & fails by some other mechanism or equivalent diameter?
Not to belabor but it suggesting a very high stripping force assuming 3DP aluminum. It even suggests 'much stronger than cast aluminum. More test weight! LOL

[Jasonb]

Does not sound right to me, the earlier attachment says a M4 x 0.5 steel bolt will yield at 2100N

Latest one says the short length of thread in ali is caplable of taking over twice that at 4620N.

I would say the bolt will rip out of the thread long before it breaks

[AlexS]

Currently also produced a couple of parts at Prototi. In table of attachment different mentioned strength. Contact was easy and fast. Able to do T6 annealing options for aluminium (stress relief and improve ductility) and other heat treatment for M300 (18NI300 Maraging steel) to make it very strong 1890 Mpa!

Only some parts have additional cnc maching and got a email quality check showed a crital oversight so the parts been reproduced. Which is good to hear.

[petertha]

Does not sound right to me, the earlier attachment says a M4 x 0.5 steel bolt will yield at 2100N
Latest one says the short length of thread in ali is caplable of taking over twice that at 4620N.
I would say the bolt will rip out of the thread long before it breaks

I have been down this Gemini path before with apparently contradictory answers. Its a weird animal, sometimes its how you pose the question. Or it selectively talks about one aspect & only when you push it does it cough up a more complete analysis. At least in textbook mechanical engineering stuff, all bets off on many other subjects. It sometimes fibs or gets mixed up. Anyway back to the 3DP failure modes, it has this to say. I'll leave it at this.

[Jasonb]

Thanks for the update.

I'm not inclined to do a destructive test on the other prints that I have but next time I order will get a small block printed to do a physical test on.

[Roger B]

I saw such a printed exhaust component at the MECA meeting last year. It looks like the rest of the exhaust system has been fabricated.

To use this printing process some form of 3D CAD is required to generate the STL files. Are there any recommendations? I currently only have 2D (Draftsight).

[Charles Lamont]

Onshape. It has a free plan (if you don't mind your work being publicly available), nothing to download - works in your browser, no files to manage, simple classy user interface design, masses of help, tutorials, forum. It will export .stl, but I have not tried it for printing yet, but am thinking of having a carb body done.


This is the finished piece. For scale,the bore is 7/16". I have started a gunmetal fabrication, but am not far along with it yet. I would need to add machining allowances for having it printed, probably in aluminium.

[Jasonb]

Fusion 360 is another that is free for home use and will produce STL and STP file sfor printing. I use it for all my CAM

I do use Alibre for drawing which can be had for a 1 off payment, you can get a months triel free.

[AlexS]

Roger, an other option is Solidworks for makers (hobby).

Currently until 13 january 24 dollar each year.

There are two options
- 3DEXPERIENCE SOLIDWORKS for Makers - > local on your pc with option cloud base storage or local
- SOLIDWORKS xDesign for Makers -> Cloud 3D CAD: Browser-based, motion studies

Both has also have rendering to generate pictures.

https://www.solidworks.com/solution/solidworks-makers

[Alyn Foundry]

Happy new year.

Love the technology and for a one off absolutely amazing however the costs currently make this process unviable for any commercial venture.
We have designed a little IC engine that can be built with a few hand tools and with a little help from Jason presented it to Craft-Cloud. At nearly £400.00 per engine ( admittedly all stainless steel ) we don’t see a market. Perhaps next year??

   Graham.

[Zephyrin]

I would need to add machining allowances for having it printed, probably in aluminium.

you mean that the metal printed part is not exactly the same size of the drawn part ?
actually I have to increase the size of my PLA printed part (104 %) to get metal casted parts the right size for my engines owing to metal shrinkage during casting, is it the same when printing metal ?

[Jasonb]

I would need to add machining allowances for having it printed, probably in aluminium.

you mean that the metal printed part is not exactly the same size of the drawn part ?
actually I have to increase the size of my PLA printed part (104 %) to get metal casted parts the right size for my engines owing to metal shrinkage during casting, is it the same when printing metal ?

The bores tend to come out a bit smaller than drawn and are rough. For something like a carb you would want a smooth surface to the inside bore so best to make the 3D model like a casting and allow a small machining allowance.

That is what I did with this stainless steel trunk guide, the model had the bore 1mm smaller and I also allowed 0.5mm of material on the feet and face of teh flange so they could all be machined perfectly flat and to exact size. The outer surfaces were not critical and the texture wa sa bonus a sit wa smare like a casting that I wanted th epart to replicate



Machining feet


Boring


Faced & drilled


Complete

[Roger B]

I have finally downloaded Fusion 360 (now Autodesk Fusion) after some language/land problems. The free version did not exist on the Swiss website, only the US one. I could register with my bluewin.ch email address but could not download the programme. Luckily I had an old yahoo.com email that allowed the download.

Now I can see how intuitive the interface is 

[Charles Lamont]

Sorry, Roger, but if you are not familiar with 3D CAD modelling, you should not expect the process to be at all intuitive.

[AVTUR]

Roger

I started on my own using Fusion 360 5 years with past knowledge of industrial solid modeling. Initially I got it all wrong but I was corrected by the model engineering club who were running tutorials during COVID lockdown. Even so the speed of learning was dictated by the slowest member of the group. In the end I bought a copy of "Autodesk Fusion 360, A Power Guide for Beginners and Intermediate Users" published by CADArtifex. It is now in its 7th edition. This has become my only guide to Fusion 360 and has yet to let me down.
 

AVTUR

[Jasonb]

Although the placement of some of the icons has changed since they were done the three part beginners videos by Lars are quite good.

<a href="https://www.youtube.com/watch?v=A5bc9c3S12g" target="_blank">http://www.youtube.com/watch?v=A5bc9c3S12g</a>

[Roger B]

Thank you for the suggestions. I have worked with some 3D cad in the past so I am aware of extrusion, constraints, components, assemblies etc. I may start off with Autodesk’s Tutorials.

I did have a quick play and put together a rather boxy crankcase with a bore for the camshaft and a couple of holes for the cylinders however I will go through the proper learning process.

[f2cf1g]

I have the Power Guide too and find it useful occasionally.  However, I got started in the very beginning with the Paul McWorter's "all new" Fusion 360 course on YouTube.  I expect he was new to Fusion himself so his demos are slow enough to follow reasonably well whereas the more experienced trainers often work much too fast to follow. Very basic but it's somewhere to start.  The bits about the Creality printer can be skipped but the rest gets across some useful information.  Autodesk have also recently released a new beginners course.

Concerning the accuracy of prints, my experience so far, with AlSi material printed by PCBWay, is similar to Vixen's, that the internal dimensions shrink and the external expand, i.e. the actual object grows a bit all round, typically 0.15-0.3mm.  In theory this might be enough to serve as a machining allowance but I always add more to be sure.  Precision is nowhere near that achievable by machining methods but probably better and more consistent than typical for hobbyist sand cast parts.  For my application, 2-stroke model aircraft engines, printing beats sand casting hands down because of the ease with which internal features such as transfer passages can be incorporated without complex coring or machining operations.

[Kim]

In addition to the other Fusion videos that have been suggested, I found Kevin's videos, from Product Design Onlilne, to be pretty helpful.  They are fairly new, having been redone in 2024, so they are showing a fairly recent version, which is helpful.  He does a "learn fusion in 30 days" approach where you do the tutorials in each video, one per day.  I did several of the first ones in a day, but then started to do them at a slower pace after I got the basics down.  Still, lots of useful concepts in each video.

https://www.youtube.com/playlist?list=PLrZ2zKOtC_-C4rWfapgngoe9o2-ng8ZBr

I also liked Lars's videos, but they are much older, and it can be challenging to translate to the new UI for someone unfamiliar with Fusion, which is likely anybody watching these videos! (It was for me, at least.  )

Kim

[GordonL]

I just tried to get a quote from Craft cloud for some pieces to get an idea on price etc. I submitted two drawings in STL format and filtered to steel and alloy. Both drawings came back as not available. Does anyone who has used this have any idea what is wrong?

[Jasonb]

I tend to use .STP Step files.

Make sure you don't have anything on the model that is too thin for the minimum detail and also check the size it comes in at, with Alibre I have to scale it to 1000% otherwise the items are 1/10th the size I want.

[GordonL]

OK Scale was the problem. a 2" square piece was 50+". It apparently was using metric instead of inches. 2" = 50.8mm. Price when rescaled was higher than I would be willing to pay. Thanks.

[maury]

Wow, this is good news and great stuff for those wanting to go the extra mile.
I think it opens the door to someone who wants to scale model a Dusenberg strait eight!

maury

[Jasonb]

Also Ideal for that compressor you are making, it would do a nice thin frame and cylinder fins.

I got a PM yesterday on another site from someone asking about the cart I made for my 1/3rd scale Galoway. Another good candidate for metal printing of the axles and bolster rather than a lot of time fabricating or doing patterns & castings.

[AlexS]

Tolerance so far for raw 3d print AiSi10Mg of 44 piston measured two point with micrometer around 44.05-44.15. Other sizes with caliper also 0.10-0.20 in the plus.

Picture second batch with the applied machining mainly for the connecting rod before annealing. M300 material when not hardened is good to machine and it contains low carbon so also weldable. 18% Nickel 9% Cobalt 5% Molybdenum. Hard and very strong when annealed.

Minimum wall thickness mostly around 1 mm and also for minimum holes.

2017 there was a stand on a technical fair showing a very huge printed engine block. Next to it an Ducati with some 3D printed parts, rims if I look right (sorry photo quality was not that good).

[CI]

It is pretty crazy the possibilities of 3D metal printing.
.

[Jasonb]

Two that dropped on my doormat last week. One will be running by tomorrow.

I'm also thinking of getting some P M Research style pipe fitting strips or trees done but printed hollow out so they only need tapping.

[crueby]

I've  had sets of elbows and tees cast in brass or bronze, with tube size openings for soldering on. Very handy. Mine were printed then lost wax cast, was a couple years ago. Do they have the powder style printing in brass or bronze yet?

[Jasonb]

No they still seem to all do printed waxes and then investment cast from those for brass & bronze

As mine would tend to get painted I am not so worried about colour so stainless would do.

[CI]

The possibilities seem endless with 3D printed metal parts.

Oil passages could be printed in parts such as crankshafts.
Steam passages could be printed in steam engines.
Water jackets could be printed in gas engines.

Very complex V-8 cylinder heads could be 3D printed.
Gas engine headers (I have seen an example here recently).

I assume you could 3D print gears ?  Have examples of that been posted already ?

Gas engine pistons, flywheels, valve covers, oil pans.

The list is endless.
Seems like this could be a big deal in the hobby with the right price break.

.

[CI]

I am new to the 3D printed metal parts concept, and don't know much about it.
Apparently there are filaments that can be obtained in various metal types.

https://facfox.com/docs/kb/comprehensive-guide-to-fdm-3d-printing-with-metal


And laser-based machines which use a thin layer of powdered metal.

.

[CI]

Edit:
This would appear to be a 3D printed pattern that is burned out in an investment process, and then cast with aluminum or some other metal using the typical investment casting method.
So not really 3D metal printing at all, but rather investment casting, like lost PLA, if I understand it correctly.

I will have to read up on this method.
I don't understand it yet.


 the service has been launched as a more cost-effective alternative to Direct Metal Laser Sintering (DMLS).
“By combining additive manufacturing with investment casting, we get the best of both worlds:


https://3dprintingindustry.com/news/metalmaker-3d-launches-rapid-prototyping-service-for-3d-printed-metal-parts-142735/


https://metalmaker3d.com/

<a href="https://www.youtube.com/watch?v=YDIW8kITAM0" target="_blank">http://www.youtube.com/watch?v=YDIW8kITAM0</a>



.

[crueby]

Yes - they can 3D print the wax master then do normal lost-wax casting, plus there are other materials now they can print the master in. The powder type laser process can do even finer details/thinner parts than the investment process, I think. I had a steam shovel bucket printed directly in steel a year or so ago, quite impressed with how it came out.

It would be interesting to get quotes on an engine block or some such in both processes and different materials, and see how the prices compare.

[CI]

Some concerns with the laser-type metal prints are said to include the following:

DMLS or Direct Metal Laser Sintering is a technique which can be classified under an additive manufacturing (AM). In this technique, metal powders are used to manufacture the parts or components in a layer by layer fashion.
This technique is widely adopted by manufacturing industries, aerospace, automobile, naval, biomedical and other industries. Recent developments of high power laser and fiber optics have also enabled DMLS to process the metallic powders in an efficient manner.
So far, the DMLS process has encountered several issues or challenges during the operation.
These issues or challenges are metallurgical defects (balling, porosity and delamination), microstructural change and evaluation of mechanical properties such as high residual stress, tension and compression behavior, surface roughness and wear analysis.


Source:
https://www.sciencedirect.com/topics/materials-science/direct-metal-laser-sintering

[Jasonb]

Things have moved on in the ten years since that article was written so watch what you find with Google. And if the current metal prints are OK for aerospace, F1 cars, etc then likely to be more than upto what we need from our models.

One of the big advantages of the printed waxes over conventional is you don't have to worry about getting the wax out of a silicon mould and you also eliminate the need for a master and the silicon mould to cast the waxes in. But still being a two stage process is more costly than printing straight off with metal but does offer a wider range of metals.

Another advantage of the online suppliers is they offer instant quotes so you can soon get an idea of what a printed metal part may cost even just by uploading a basic design. Then with the knowledge of likely costs can then develop the design to suit whether you still want to use 3DMP or more traditional casting/fabrication/cutting from solid.

If it is a small item it may well fall within the minimum job cost that a lot of the online companies use so worth playing about with quantities or grouping jobs together. Those two prints I posted earlier would have cost me about £50 each had I ordered them individually but the two cost £55 when put on one order.

Costs are partly based on volume so it is also worth roughing in any holes or cavities. As an example I priced the solid version of the attached pump up to get an idea of costs. I then went back and added all the cores and roughed out holes and the cost came down by 20%. It only cost me a bit of time infront of the 'puter rather than having to make several core boxes and mould the cores.

[CI]

It is an impressive technology.
Changes the options/perspectives of how one can build model engines, with some interesting twists.
Sort of leapfrogs right over CNC, and over a lot of traditional casting methods too.

3D printed metal is not in the cards for me at the moment, but I can see where this would be and already is very useful already to many in this hobby.
I expect this method to continue to become more popular over time.

.

[CI]

Looks like I am late to the discussion.
Here is a 3D printed metal thread that has been around for a while.

https://www.modelenginemaker.com/index.php/topic,7391.0.html


and also a more recent thread here:

Post #1401:
Part 45    3DP printed metal parts for the coolant, crankcase vent and exhaust pipes
https://www.modelenginemaker.com/index.php/topic,5142.msg301784/topicseen.html#msg301784


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[Fj45]

 Craftcloud offer brass and bronze printing.

[Jasonb]

Craftcloud offer brass and bronze printing.

As I said earlier they do not print brass or bronze. Same for just about all the other outlets.

They print a wax and then investment cast from that