Mercedes-Benz W165 Grand Prix engine in 1:3 scale

[Michael S.]

It's really impressive how well it all fits together. It looks great.

Michael

[Vixen]

Hello Michael,

These exhaust pipes demonstrate 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 about straightening the post printing warp (bend) in the exhaust pipes. However, I found the  typical elongation to failure values of 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

[Roger B]

Those prints are really quite spectacular especially with such thin walls     

[Art K]

Mike,
Looks like the printed headers worked and look great! I haven't come across anything yet that I would need to have printed but there's time yet.
Art

[f2cf1g]

Mike, I'm late to this thread but very interested in the 3D printed manifold which looks superb, like the rest of the engine.  Can you tell me if any supports were used inside the tubes so far as you can tell?
Thanks, Roy

[Vixen]

Hello Roy,

With laser sintered printing, the print bed is filled with metal powder and smoothed off. The laser melts and fuses the top layer of metal powder together, then another thin layer of metal powder is added and the laser fuses that layer to the previous ones. This layering and laser fusing is repeated thousands of times. No supports are required, the metal powder fills the inside of the tubes and acts as the support. The unused powder is removed from inside the tubes when the print has been completed. The surface texture is the same inside as out. Some of those pipes are only 0.8mm thick, below that, porosity can become an issue.

Mike

[Laurentic]

Mike - there are times I am in awe of modern technology.  My daughter's ankle ligament reconstruction with the use of a carbon fibre brace secured with 'bolts' that in time become bone and therefore bond invisibly with the original bone they are screwed into is one. 

Your laser sintered aluminium printed manifold pipes is another.  Wonderful stuff.  And, by the sound of it, affordably priced too.

Chris

[Vixen]

3D printing technology is advancing so fast and modern manufacturing methods are evolving, which bare no resemblance to traditional methods.

3D printed resin sand moulds for foundry work have replacing the old school hand rammed sand moulds. Norbet, another of out MEM members, has used 3D printed resin sand moulds to cast the full size replica crank cases for his historic NSU race bike restorations.

3D printed metal parts are now readily available from an increasing number of 'print from file' firms. 3D printing in metal can and will replace 'lost wax' casting for intricate detailed work. Many model engineers, like Jason, are now turning over to 'castings' which have been 3D printed. These are usually of much more accurate and finer quality than traditional sand 'mouldy' castings.

With 3D metal printing you pay for the amount of metal powder consumed. My thin wall (0.8mm) pipes did not consume a lot of raw material so were very cost effective. A heavier engine 'casting' would be much more expensive and may no longer be as cost effective. Turn round time for 3D metal prints is usually shorter than the time required to ship them to you. Fortunately all the print houses offer an almost immediate quotation on receipt of your 3D drawing file (.STL); so you know what you are letting yourself in for and when you can expect a delivery.

Times, they are a changing.

Mike

[Laurentic]

That was a very interesting overview of 3D printing Mike - Thank you for that.

Hope you haven't told Jo how good the 3D printing of parts are so much better than sand 'mouldy' castings - you know how she drools over castings......

Chris

[Vixen]

That was a very interesting overview of 3D printing Mike - Thank you for that.

Hope you haven't told Jo how good the 3D printing of parts are so much better than sand 'mouldy' castings - you know how she drools over castings......

Chris

I never knew that, did she say     Hi Jo !!

Mike

[Jasonb]

I've certainly seen supports being used so it is not just the powder that supports the part.

Good example on these bike frame lugs and how the supports are removed!

<a href="https://www.youtube.com/watch?v=FweX78b87H4" target="_blank">http://www.youtube.com/watch?v=FweX78b87H4</a>

They are using a Renishaw printer and their videos also show some parts with supports

https://www.renishaw.com/en/renam-500q--48429?srsltid=AfmBOoqDkrSKN3oaJdPQ_s336T7ckMq92IAWWhBWmE-tlugEKR7CFKsy

Also if you look down the page of ProtoTi that I have used one of the cons is that supports need to be removed.

https://www.prototi.com/capabilities/3d-printing/slm-3d-printing/