/diy/ - Do It Yourself

So, I've learned a lot more about casting the fifth jellyfish - always triple check the fucking mold. Turns out I had a shit print for a retaining pin and that went loose in the first hot pour.

I decided to pour in 1cm tall increments due to temperature - due to the first pour being too fluid and hot, the break in the retaining pin on the first pour freaked me out about temperature and made me attempt lower, less plastic temperatures.

In the following cm pours, I've went cooler and cooler to get a more viscous pour. I've poured on the pillar and this repeated pouring on the central pillar made a rather big blob of material at the rear-most end.

This blob, combined with my cooler pours, did not fuse the surface of the previous pour with the next one, hence the voids and the rather large gash up at the rear-most end.

Between pours, I had put the cast in the freezer for 5-10 minutes, depending on how hot it felt on the exterior. At the final pour, I had placed it in the freezer for half an hour. This time was not enough as it was still very warm!

I've melted a whole pot-ful of it and this resulted in very messy pours. I highly recommend melting in small batches!

I've had a go with a probe thermometer while melting. 100C is approaching viscous, 80 was far too viscous to pour, and 140 and above is very fluid - far too hot to work with PLA, at least with my cooling conditions.

Will rework the two-piece tube mold and make it into a 3 or 4 piece. The "head" end is fine as it is. "tentacle" design needs some reworking to remove sharper corners, but whatever.