Design Requirements for 3D Printing with Metal and 3D Printed Alloy Parts

Design Requirements for 3D Printing with Metal and 3D Printed Alloy Parts
We have a number of 3D printing companies that offer 3D printing metal services. You can upload any STL file and get an instant quote. Some general instructions are included below; however these may be slightly different between companies.

One of the main options for 3D printer metal materials is a material that is composed of 60% stainless steel and 40% bronze infiltrant. This material offers good mechanical properties and comes with both an annealed and non-annealed condition and can be machined, welded and polished and has great resistance to wear.

Application:
This specific material system is great for parts exposed to highly abrasive environments; including pump parts, down-hole drilling parts as well as equipment for mining. Additional applications include industrial parts, parts for molds & tooling, art structures and hardware that’s decorative.

Composition: Stainless Steel: Alloy 420, Bronze: 90% / Cu / 10% sn

Typical Material Properties:
Typical material properties for metal 3d printing

Surface Finish:
3d printer metal: surface finishes available

3D printing metal part, raw finish and polished finish

Available Finishes: Gold Plated, Antique Bronze Patina, Damascus Steel Patina, Nickel Plated, Wheat Penny Patina, Medieval Pewter Patina

Note: Anti-corrosion treatments are also available.
Accepted File Formats: .prt, .sldprt, .3dm, .iges, .stp, .step, .3ds, .obj, .raw, .wrl
Export: Please export as a binary stl with a mesh tolerance of 0.0001 inches or .000254 mm

Example 3D Printed Metal Finishes:
Example Finishes for 3D Printing Metal Designs

Part Geometry Guidelines for Successful Metal Printing Production:

The following guidelines present what the shop can and cannot successfully process in production. In some cases the part may never fall under production due to size or our thermal limitations and we will not be able to do it.

The following guidelines are only guidelines and all parts are reviewed for printability. As our process matures eventually parts like this in the examples might be possible eventually.

Part guidelines for small size parts:

Parts that are 2” x 2” x 2” (50mm x 50mm x 50mm) or less ca be printed with 95% success rate using or S4 material. The walls should be no less that 3mm thick. Also designs that are thin need to be supported structural so they can support themselves. The head would need to have supports/tie bars from one strip to the next. See Example 1a:

Another example in 2a the droplet necks down to a very thin cross-section. The droplet on the end is too heavy to support that small cross-section. See circle in 2a:

3d printing metal cross-sectional support

3d metal printer cross sectional size to thin

In example 4a the stigma is too thin and when depowdering it will blow off. It would need to be 3mm thick for it to survive or support would need to be placed in and then cut off. Also the pedals are not supported except at the receptacle. Again metal powder is very dense compared to plastic so it needs supports that would be cut off later.

In example 4b this is an extreme case where the ball is basically hanging on a string. It would never come out of the metal powder along with the flower not being supported etc.
In example 4c this is although we could print it we could not keep the parts loose in the furnace. The furnace goes up to 1150c which allows part to get hard so what happens is the loose parts fuse together and cannot be broken apart.

3d printing services metal - loses the loose parts during the printing process

printer 3d printing metal

In example 4d although very cool looking, we could never get out of the powder with out it falling apart. Think of it this way, imagine a spider web. It looks really cool how the spider can create such an intricate web. Some webs are beautiful but then try to move it from where the spider created it. It would be a mess and even if you could remove it from where it was originally created, how could you lay it down with out messing it up. It can’t be done. Pieces would just break off.

chain and bird 3d printing with metal

Part guidelines for medium size parts:

Parts that are 8” x 8” x 4” (203mm x 203mm x 102mm) or less can be printed with 90% success rate using our S4 material. Thin walls should be no less that 3mm thick. All contours can be printed but surface finish can vary depending one the axis. Surface finish can be improved by rotating the part to reduce the amount of layering steps, but the part might take longer to print if taller in the Z-axis and cost more because of the rotation. Delicate parts like Artist parts can be printed with very good success but self supporting cross-sectional areas should NOT be less than 3mm for long distances.

In the example picture of 5e thin areas can be done if you keep to the 3mm as in the picture where the arrow points out. The buffalo has different thin features but they are supported with a frame work around it.

3D printing metal cow skull

  • Dimensional tolerances are at +/- .005” to as high as +/- .008 per inch and +/- .005 for every inch after.
  • Hardness for S4 is around 15HRc to 19 HRc
  • Surface finish is roughly around 200-250 Ra after tumbling

Part guidelines for large size parts:

Parts that are larger than 11” x 11” x 2” (280mm x 280mm x 50mm) can be printed with 50% success rate using our S4 material. Printing is not a problem but thermal processing is an issue that is still being resolved

  • Dimensional tolerances are at +/- .010” (.254mm) to as high as +/- .020. (.508mm) with a +/- .005 per inch after.
  • Hardness for S4 is variable depending where on the part.
  • Surface finish is roughly around 400 to 600 Ra.

3d printed metal horse

Part guidelines for loose parts:

metal-1

metal-2 If you need help converting your 3D model into a 3D printer friendly format? Send it to us and we’ll help you out!

Please see the video below for more information about uploading your 3D printing file for an instant quote on Maker6.

Maker6: How to Get an Instant 3D Printing Price Quote from CAD Crowd on Vimeo.

General requirements & instructions when preparing 3D files for 3D printing

Requirements & instructions for preparing 3D files for 3D printing/CNC
Please refer to the notes below when getting 3D printing services help from the 3D printing companies on Maker6.

  • Preparing Files for 3D Printing

Any 3D software can be used to create a 3D design: however the files need to be exported to .STL (monochrome parts) for accurate quoting. Also, if your print is going to be created in color, then include .WRL (multicolor/textured parts) as well. Other formats like .3DS, .STP or even .OBJ are optional, some 3D printers can, some cannot read them directly.

When exporting colored/textured parts to .WRL format, auto created bitmap texture file needs to be uploaded next to the geometry .WRL file

  • File Export Quality

When exporting to .STL format take care about export “quality”. STL (.WRL as well) are formats for storing triangulated mesh data meaning all created surfaces/solids will be polygonised – transferred from mathematical to the “physical” level of XXX connected triangles (for more info on polygonal mesh check this link: http://en.wikipedia.org/wiki/Polygon_mesh or search Google). During the export process you can control size and number of these triangles – more triangles gives you better quality – needless to say, this will also affect your file size: more triangles, more in file size.

  • Object Normals and Orientation

All object normals must be oriented “outside”. Think about this as if you would have a cardboard box in front of you – inside it’s just a plain brown cardboard box because nobody looks inside, but on the face(out)side you have that colorful print visible to everybody. It’s the same with 3D printing: if you want your 3D design to be visible to 3D printer, all your polygons need to be facing same direction – visible outside. More technical info on normals find here: http://en.wikipedia.org/wiki/Normal_(geometry)

  • Creating & Converting Files

When creating (or converting) a 3D file for 3D printing purposes the most important thing is achieving Water Tight Model (WTM) or Manifold. What is manifold? The easiest way to think about this is if you would fill your 3D model with water, would you have any leaks? If your model has non-manifold edges, water would leak out.

Non-manifold edges are parts of the model where it has not been connected to create a perfect joint. This is a common occurrence during the design phase, when two components are “connected” in the software and on the screen, but in reality, the seams between the two objects have not been joined at all. Even the smallest gap (0.00000001 mm) would be sufficient to render model as non-manifold. In other cases, you may have components of the model that overlap one another, confusing the 3D printer slicing engine (algorithm that will slice any 3D part in to layers understandable to 3D printer).

Generally all 3D printers require objects to be 2–manifold, meaning each edge should be connected to exactly two faces. ‘Open’ objects are typically 1-manifold, models containing unwanted and overlaping faces are 3- or more manifold. Anyhow, there are bunch of software that will check your part for manifoldness (Blender is free and fast) – the safest way to achieving manifoldness does not exist (maybe when working with MCAD tools such as SolidWorks or Catia) – it’s all on the designer and his capabilities to resolve this. This is not an easy topic to master but it’s necessary when working with 3D printers – please search a Youtube for more on how to do manifold models. As always, fin more on manifold at: http://en.wikipedia.org/wiki/Manifold

  • Design with Support in Mind

When designing the part to be printed, think about support also. All 3D printing technologies require support of the printed parts – additional material which will hold everything in the place and support the models parts which cannot „stand“ by themselves. If we take an example from construction, if you are building a hut on water, you would need support structures to hold it above the water surface but not over complete surface – just on few strategicly (staticly) important spots. It’s the same with 3D printing – in almost all case this support will be generated automatically, but designer needs to be aware that some geometries cannot be produced on some of the 3D printing technologies. The specifics will be covered in the section where we talk about individual 3D printing technologies.

For more help with 3D printing, please refer to our support page as a resource. If you’re looking for a 3D printer, please click to get an instant quote on local 3D printing services. or see the video below for more information on how to get started:

Maker6: How to Get an Instant 3D Printing Price Quote from CAD Crowd on Vimeo.