Metal 3d printing

I’m currently on a personal project of doing my own watch and I was curious about people here that had experience with 3d printing in metal. Since it is a watch I am looking for a perfect polished finish of the surface of the parts. However if I look on various websites such as Shapeways or others, the surface doesn’t appear to be “perfect”.

Can 3d printed be polished to perfection or the material is itself a bit porous like regular plastic 3d printing?

Thanks in advance,


It can be polished but it will be a bit pricey.
Have you considered having it machined by an overseas RP house?

Yup, the other option is to machine the parts at a prototyping company. I’m just evaluating options at this point.

Hey Philippe,

I only have experience with Shapeways 3D printed plastic but sanding that yourself can result in a smooth finish closer to an injection molded part. Even the “polishing” process Shapeways provides for 3D printed metal and plastic does not leave it with a close to injection molded surface quality. Shapeways does offer 3D printed wax as a material you can get if you want to do your own lost wax casting at home. The more expensive shiny metals they offer are done with their same 3d printed lost wax casting.

I wonder if you could get a wax 3d print and use heat or steam to smooth the finish of the wax before casting for a smooth finish!

Thanks for the suggestions. However, lost wax is probably not precise enough for the tight tolerances I’m looking for. Machining seems to be the better option the more I think about it.

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Thanks Keno for your information ! I definitively want less bumps for the type of product I want.

Hey Phillipe,

If it helps, I have tried doing something very similar. I have done some work on a personal project involving a watch. I went down the route of metal 3d printing with shapeways, with mixed results.
For a start, the finish is not brilliant. Just as Gerry said, I too ended up using a dremel on it to try and make it more ‘polished’, but the end result looks more ‘antique’ than the modern look I was hoping for. If you want to have it look like an industrial type finish, it isn’t brilliant.
Secondly, the dimensional accuracy of the shapeways method is nowhere near close enough for something as small as a watch. The parts all fit together beautifully, but the ‘growth’ of the parts meant that they were all incorrect dimensions. This really caused me issues with some of the other parts (such as the glass), as it no longer fitted. Again, had to break out the dremel.
Finally, there is the lead time. I expect you would want the material thickness to be fairly low, and so there may be some issues with the manufacturing itself. I had a 3 week lead time for the parts to be made, only for the order to then be cancelled after 3 weeks because some of the sections couldn’t print properly. This meant the lead time for prototypes became 6 or 9 weeks, which is rather frustrating.

With the cost of it, I would probably look at the CNC route. Would be useful to know if you find any good international CNC people who you would recommend - still looking myself!
Best of luck with the project!

I’ve seen mixed results also.

We were doing some cutlery at work and had some prototypes printed in Stainless Steel by Shapeways and the quality was spotty as well as a hefty pricetag. I think it cost about $2000 for the print and an extra $1000 for them to polish it properly.

Some pieces turned out OK but others had a few thick noticeable lines in them. Sorry I can’t post any pictures.

As a watch is usually a high value item I would assume you’re willing to invest a decent amount of $$$ to have your own made, unless the shape is something unusual I’d look in to have a Far East prototyper take a look. I have a handful that email me every week/add me on Linkedin I could direct you to :wink:

3D printed steel will be way too heavy given the minimum wall thickness.

Gold plated brass or polished / premium silver work nice for jewellery, and have a very smooth finish, similar to a cast.
The disadvantages and limitations:

  • small spots can appear in the silver
  • surfaces are smooth only when at least slightly curved and large enough - small details do not come out sharp and planar surfaces come out dimpled
  • the dimensional accuracy is not great so if you want multiple pieces to snugly fit together, it work most likely not work as you intended.

I recommend specialized machines like the Sisma MYSINT100 - SLM or DMLS machines.

Contact Best Cast in NJ – they will print a very high-res wax pattern and direct investment cast in whatever metal you want. Shrinkage will be very, very small. You’ll have to do all the post finishing yourself but you’ll be starting from a pretty smooth surface.

Other then shapeways anyone know of a resource for 3d printed ceramic?

HRhV – Thanks for your detailed information. I definitively got that antique vibe by looking at the various pictures. On another subject, did you do the dial on your watch project? I’ve seen various ways on how to achieve something decent but it onvolves a lot of small intricate details, I’m simply curious if you tackled this problem.

Sketchgrad – Good idea, my LinkedIn inbox is flooded with Asian prototyping firms publicity. I’ll ask a few quotes

ralphzoontjens – Thanks for the insights.

Dan Lewis – Very interesting. I am definitively keeping the contact info for when I’m going to ask for quotes.

Then try a few of those asian prototyping firms. In our experience they always give you a good price the first time and then slowly start to increase their prices, so it’s always good to get a few quotes every time. STAR-PROTOTYPE, HLHPROTOTYPES, RPPROTOTYPE, etc. Also pay attention to their notes and how they are going to do it…it always varies from company to company.

I worked recently with a company that did CNC models and made a cast from those parts. The pricing was similar to what I would have paid getting them machined ($500USD vs $400USD).

Pop me a pm if you’re interested.

agree with john there - the cost for an investment cast tool is not much more than a cnc model (like maybe 1k vs $800). and you can get many multiples that way, and in different materials.

if i need a mirror polish, i go with 7k series machined aluminum… polishes VERY well