Jump to content
Ultimaker Community of 3D Printing Experts

stl to step or iges Conversion for Mass Production

Recommended Posts

When I first got into 3D printing, I did it to prototype some ideas that maybe I could mass produce some day. Well, I've got a good product now, but I never knew I would have to find a way to make a mesh into a solid in a CAD based program. I can't find anyone that can either mass produce from a stl file or someone that can convert my file for me. I have tried to convert it in FreeCAD and Fusion 360 without any success. The object I have might be considered complex since it had lots of curves. I think this might be causing my conversion problem.


I guess that I could spend some time and try to learn how to design in CAD, but that's going to be an undertaking.


Does anyone know:

1) A simple way to make this conversion

2) Someone that can convert this file for me at a reasonable price

3) A company that can make a plastic injection mold that can be made from a stl mesh file?


Thanks community!

Share this post

Link to post
Share on other sites

Hello and welcome! :)


I'm still new into the 3D printing community, so, maybe someone will make me wrong, but I don't think there is a simple way to turn a mesh into a solid for conversion into stl and printing. From what I've read and was told, depending on the complexity of the object, you can sometime just make some modifications into a 3D program to turn it into a solid, or, you're better off starting from scratch and rebuilding your object directly into the 3D program.


I know from personal experience that mesh created in Sketchup, for example, become an absolute nightmare when exported into an stl file, and you're saving time by rebuilding the whole thing in another program that builds solids from the start.

Share this post

Link to post
Share on other sites

Mass production with injection moulding is quite complex. There are lots of things to consider, such as wall thickness, bending radius, no sudden changes in part thickness, sink-defects, avoiding voids, drafted side walls to be able to release the model from the mould, no undercuts, carefull placement of seam-lines, carefull consideration of mounting options and screw holes, and so on.


I would suggest you google for words like: injection moulding manual

or: how to design for injection moulding

or similar terms. Search for PDF documents.


Big plastic manufacturing companies like Bayer, BASF and lots of others have published good manuals online on designing for injection moulding.


And then probably you will need to redesign your part in a vectorbased editor, incorporating all these requirements from the very beginning. Think of editors like: DesignSpark Mechanical (freeware, but its STEP- and IGES export is to be payed), Onshape, SolidWorks, SpaceClaim, Rhino, Form-Z, and lots of others that I can't immediately remember. (Don't use SketchUp.)


If you only want to mass produce relatively few models, on a hobby-scale or for artwork, you could 3D-print one item, post-process that until really perfect (sand, polish,...), and then make silicone moulds from it. And then cast in resin, gypsum, concrete,... Or you could print multiple models, and use them for casting in metal. Some jewelry designers here do that.


Search on Youtube for good videos on mould making and casting, there are lots of really good ones available (and lots of crap too of course, so you need to filter and use common sense).


It is all very interesting, but do expect quite a learning curve.


Share this post

Link to post
Share on other sites

Thanks for the input. Yes, I do suspect the learning curve will be quite large for learning how to make a design that is ready for injection moulding. I guess I never realized this when I started tinkering with all of this. I'm second guess proceeding on my own and may want to take a different route on my ideas. Thanks for the reference information. It's a good starting place to look into before I decide to learn some new programs.


So, is anyone good with licensing their ideas!? :)

Share this post

Link to post
Share on other sites

I think the answer at this stage is to find yourself a Solidworks or Inventor engineer who has experience in designing for injection moulding manufacturing. They can tell you whether your design can be easily made using injection moulding or whether there are some issues, which he can correct. He can also advise you on the easiest way to get your model into the CAD software along with correct dimensions etc. Now that is not easy, indeed possibly impossible. We have imported STEP files into Solidworks but you loose all the dimensions - well at least we did!


But your model shows the assembly and whatever software you used to produce it can give you all the dimensions needed. Worst case is that the engineer can redesign it in his software from scratch with your dimensions and produce a no doubt modified file for the manufacturer. It is impossible to say how much time would be needed without a view of the model but to give you an idea we would charge £120 for the first 4 hours and then £175 a day thereafter. We are no use to you, wherever you live (bring back the old forum!) as whilst we design and prototype for injection moulding we are not experts in injection moulding design considerations. Also not to forget that no doubt some injection moulders will have this expertise anyway ad so you could go direct to them.


Share this post

Link to post
Share on other sites

The design rules for injection moulding are quite strickt, otherwise the part can not be mass produced at all. Startup costs (=mainly design adaptation and mould production) are very high: expect 10000s of euros for high volume production moulds.


The rules for silicone moulds and resin casting are way more flexible, but then of course production volume is very low and production cost per item is much higher. So this is suitable for art reproductions, hobby, low scale tests, but not for cheap toys that have to compete with commercial stuff.


I just remember that there are companies that do deliver quick injection moulding services, and also other services like 3D-printing and 3D-editing, for relatively low volumes (100...1000...10000 parts). For example "ProtoLabs" in the UK. They have good technical info and guidelines on their website. I would suggest you study these. In Belgium we have the very well known companies "Materialise" (big size 3D-printing, mostly plastics), "Melotte" (also metals), and several big others which I don't remember. Might be a good idea to study their services too.


If your design is a technical innovation (=has to be new, innovative, technology, producable) then you could apply for a patent. But expect that to cost 10000s of euros. Copyright does not apply to technological inventions and methods.


If your design is a piece of art or design, it cannot be patented, but it can be registered and protected as a model. This in addition to automatically applying copyrights (in Europe, maybe different elsewhere).


If you would speak Dutch or French, and live in Europe, have a look at the website of the Belgian government concerning protection of intellectual properties: https://economie.fgov.be/nl/themas/intellectuele-eigendom

This gives excellent info in simple language. Or find similar sites from other governments, institutions or companies.


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Our picks

    • Ultimaker Cura | a new interface
      We're not only trying to always make Ultimaker Cura better with the usual new features and improvements we build, but we're also trying to make it more pleasant to operate. The interface was the focus for the upcoming release, from which we would already like to present you the first glance. 
        • Like
      • 130 replies
    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 replies

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!