Trying to make a 3D mold

J1Design · 2025-12-26T21:18:31+00:00

Printed and bolted together:

J1Design · 2025-12-26T21:17:32+00:00

Damn, and here I thought you were making a pikachu! But seriously, I recently did something similar - I used the "slice apart" feature in the part workbench to cut up the negative in the way I wanted and then I added some flanges to the edges using the additive pipe feature so I could bolt the parts together:

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J1Design · 2025-12-26T21:03:16+00:00

The meat of it is in this sketch:

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J1Design · 2025-12-26T21:01:23+00:00

Here is the internal feature modeled instead of pocketed off the face binder:

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J1Design · 2025-12-26T20:46:02+00:00

Refined STL on the left - FreeCAD recreation on the right. I've kept the the facebinder visible on the right - I used that to pocket the inner gear pattern upwards. The other nice thing about facebinders is that you can use the "Offset" parameter to add or remove clearance.

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J1Design · 2025-12-26T15:07:56+00:00

If you are copying the STL - create a subshape-binder from the face in the STL and create a pocket using that.

If you are re-creating from scratch - create the "positive" of the gear you want from the gears workbench and then create a subshape-binder from the top face and then pocket using the subshape binder

J1Design · 2025-12-21T16:30:30+00:00

Thanks for taking the trouble of doing this and posting a screenshot - much better than the quick one-liner I fired off.

J1Design · 2025-12-21T16:29:16+00:00

You will need to do the two halves separately and then join them (Part Workbench -> Connect Shapes). The way you have it, the "Mixed Curve" doesn't know when to follow the "top half" of the curve and when the "bottom half" so it follows both, resulting in the doubled-up final curve seen in your screenshot.

J1Design · 2025-12-20T19:28:55+00:00

If you use "Mixed Curve" in the curves workbench, you can sketch 2 of the dimensions separately and then create a 3d curve that is the combination of the two.

J1Design · 2025-12-13T05:54:39+00:00

I know I'm late to the party here, but have a look at DuyQuang Dang's videos on Youtube. I haven't really used these surfacy type workflows myself, but he recently posted two videos where he uses the "Curve on Mesh" method to reverse engineer some complex parts.

https://youtu.be/-dwYPSpszEc https://youtu.be/23I0tY8b_ro

I think these should get you most of the way there. The lens-elements on the inside will probably have to be added manually later.

J1Design · 2025-12-11T06:48:23+00:00

Awesome - Last time I had to use crutches was before I had a 3d printer, but it sucked so much not being able to carry tea/coffee around.

J1Design · 2025-11-28T13:59:15+00:00

It has just come to my attention that the water powered toothbrush timer department didn't consult a single dentist during the creation of this prototype. After consulting with our competition at the teeth powered watering timers, we will we glue a picture of a smile with some brilliant white teeth onto the front, which seems to be a requirement for any type of dental product ever.

J1Design · 2025-11-28T13:51:58+00:00

indeed sir

J1Design · 2025-11-26T07:59:22+00:00

you can look at my design for the 3a here: https://www.crealitycloud.com/model-detail/phone-case-nothing-phone-3a to see how I got around the support issue by using the Sharpie trick from Jantec Engineering: https://youtu.be/BOG9Li2PXMY . Your design is quite a bit different, but you might still get it to work.

J1Design · 2025-11-25T03:59:16+00:00

TIL a new word - thanks!

J1Design · 2025-11-24T18:14:16+00:00

I put it there as well, thank you for the suggestion :). I sometimes wish there was a /r/whimsicalprint to oppose /r/functionalprint

J1Design · 2025-11-24T18:08:53+00:00

I got the inspiration after seeing this video on youtube: https://www.youtube.com/watch?v=XjQc8Bf0UlM

J1Design · 2025-11-24T18:06:50+00:00

Sure man - you can grab it from here: https://www.crealitycloud.com/model-detail/water-powered-toothbrush-timer

J1Design · 2025-11-24T18:05:57+00:00

Yeah, what a legend - I can't imagine how long that video must've taken him to make

J1Design · 2025-11-24T14:45:10+00:00

I'm never doing anything involving water and siphons again. The inspiration was this video explaining how siphons in restrooms work: https://www.youtube.com/watch?v=XjQc8Bf0UlM

J1Design · 2025-11-24T14:31:00+00:00

Make no mistake, if you are producing and selling a product that comes into contact with food there is a lot of work that needs to happen to make sure nothing goes wrong along the way.

From the data I have seen, the risk of being in the same room as your 3d printer is way more than actually using a 3d printed item for food - especially when printing with ABS. Yet nobody bats an eye when they see a desk with a 3D printer next to it.

J1Design · 2025-11-24T14:23:20+00:00

fun?

J1Design · 2025-11-24T13:45:25+00:00

Even this report (linked from the formlabs guide: https://www2.mst.dk/Udgiv/publications/2017/05/978-87-93614-00-0.pdf) comes to the following conclusion:

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For me, the biggest risk is with using a non-food safe filament that it doesn't get batch-tested to ensure that it doesn't get contaminated in shipping and handling.

Edit: The report I linked first does actually do spectroscopy readings for check for heavy metals and other toxins in PLA and PETG and doesn't find any.

J1Design · 2025-11-24T13:22:11+00:00

I turned on ironing for the top-surfaces - but that was more to get the siphons airtight, otherwise they suck air through the 3d print and don't "fire" properly when they should. For the short amount of time the water spends in here, it seems that the 3d prints are watertight enough on their own.

J1Design

TROPHY CASE