I hate to ask a somewhat broad question, but here I am with no one else to turn to 😅. Specifically, my question is: What should I do first?

Let me explain the context to make my question a little clearer: I absolutely love drinking tea and I want to be able to brew it on the go. After trying out different sorts of tumblers, I finally found one that I really like. Its only problem is that it doesn't have a removable strainer, which makes it difficult to clean, among other things. Here's the link to it: https://www.taotealeaf.com/tao-tea-tumbler/

The first thing I did was to design what I had in mind with a program called FreeCAD. After exporting it as an STL file and slicing it with Cura, I was able to print a prototype on my 3D printer and adjust my original design. While I am somewhat more confident in the design now, I'm still unsure about how big the gaps should be between the glass housing and the outer metal (currently 0.5mm), between the metal rod in the center and the inner metal (also 0.5mm), and between the threading for the top and bottom parts.

Since I never really had any training in this field, I don't know what steps I might have missed or what remains to be done before I find someone to etch my design out of a block of food-grade stainless steel. Again, the question is: What should I do first?

rough sketch of the strainer

  • $\begingroup$ This doesn't feel like engineering to me. It feels like a fab project. $\endgroup$
    – Tiger Guy
    Commented Aug 25, 2023 at 3:35

2 Answers 2


You may experience a disassociation between the 3D printed part and a machined (not etched) version. The 3D printer will have some dimensional differences from the design you created and sliced. If you can measure your part at various locations and match them to your design within certain tolerances (0.05 mm, 0.5 mm?) you stand a better chance of having a machinist create the object you require.

Setting up a CNC machining center is going to be a big part of the expense of creating your object, otherwise I would recommend that you determine the critical segment of the object and have a test piece machined.

I visited the link you provided but cannot determine what component you are creating as it fits with the main tumbler. If you can post an image or a screenshot of your work, it would be helpful.

To answer your question, the next step is to ensure your measurements will match a machined part, primarily to be confident that you'll have success with the smallest possible expense.

Photos posted as an edit to your question would be the most valuable to the community.

To clarify "machined part:" The 3D printed model you created when converted to stainless steel will be accomplished by using conventional machining practices. The result is a machined part.

Critical segment: some portion of your creation will have dimensions for which precise measurement is not important. As I do not yet know the design you've constructed, I can only be generic. A cylinder enclosing material (tea leaves?) would not have to be precise for the outside or inside diameters, unless they engage another component. On the other hand, a threaded segment would be critical in that the threads must be constructed in a manner to properly engage the component into which they are screwed.

  • $\begingroup$ Hi! Thank you for your quick response! 😁 I can absolutely send you a picture of my sketches - I can even send you the STL files. The part is for the upper, smaller cavity where the tea leaves go. I made my measurements with a digital caliper, which is accurate to a 100th of a millimeter. Could you also elaborate a bit on your answer? What do you mean by ‘machined part’ and ‘critical segment’? $\endgroup$ Commented Aug 24, 2023 at 21:32

First: Select an appropriate food-grade material.

Don't poison yourself or others with toxic materials that are in prolonged contact with hot water.

Some versions of brass have relatively high concentrations of lead. Materials in plumbing systems are now required to be "lead-free."


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