For our visit to Star Wars: Galaxy's Edge this year, I wanted to do some cosplay/bounding featuring kyber crystals. But I didn't have any yet AND didn't want to spend upwards of $20 each to feature a half dozen in my planned props.
That's when the idea of cheap hot-glue based stand-ins came to me. These molds are the result. These two part molds will allow you to make kyber crystals similar in shape to those sold in Disney Parks. The positive crystals are also included - for FDM printing you may need to find the best orientation for your slicer.
Of course, making new crystals had me revisiting my old models for the kyber crystal tubes as well. These are rebuilt from the ground up now that I have a real tube in hand. You'll find three cap designs; solid and necklace are based around the official product. The third - slotted - is designed to easily light the tubes using a balloon light (I designed it to take this model from Temu). I found vase printing the outer walls worked very well both for efficiency and quality, but I've included models for both vase and traditional prints.
On molding hot glue:
I tried to make injection molds at first, but found the hot glue wasn't cooperating as well as I'd have hoped. So instead I began filling each half of the mold quickly and separately, then pressing them together to fuse the two halves. What was the injection port then became an overflow valve.
For mold release, to keep with the budget theme I used WD-40. It worked exceedingly well. I sprayed the interior of the mold and lightly rubbed it down, then immediately applied the hot glue.
The author marked this model as their own original creation.