Surface Finish On Color Processed Versatile Plastic

Last June I had some puzzle pieces printed in "processed versatile plastic". The prints had a beautiful, smooth finished, and the pieces fit together beautifully.

Last month I had the same pieces printed with exactly same order, and they surface finish was very rough. I tried to make them work, but the pieces bound together, and required significant sanding to be smooth enough to fit together. Sanding removes much of the color.

Thinking Shapeways perhaps skipped the "processing" step, I asked them to re-make the parts, and they agreed to do so. There was some improvement the second time around, but the finish wasn't nearly as nice as what I received last June.

Have others experienced this sort of inconsistency? Was the finish I received last June just a fluke?

Below is a comparison of the finishes. The squares about 6cm (2.4") across.

Wow, that's a huge difference!

There's an epilogue to the story: When Shapeways re-made the parts, the good news is they came back with a smoother finish (see previous photo). However, I tried to actually assemble these parts today, and the result was even worse.

You see, for some reason, the re-make was done as three separate orders, and the three parts arrived in individual boxes 4 - 7 days apart from each other. The parts - puzzle pieces - depend on being exactly the same size. However, because the parts were each made on different days (presumably in different batches, perhaps by different machines?) the tolerances were way off. They are designed to work with a tolerance of 0.1mm, but in this case two of the parts were actually around 0.5mm apart from each other. So yes, the surface was "smoother", but the interior surfaces required substantial sanding to work, and the result didn't fit together cleanly.

The original parts with the smooth finish (made in June) worked perfectly the first try. The "rough" parts made in December just required a light sanding to smooth the mating surfaces. But the remade parts in January required heavy sanding and ultimately did not fit well.

Moral: Make the same parts from the same batch on the same machine.

I have only tested back versatile plastic, when I broke the piece in a half, inside was white. I don't understand the color process, did they paint it over white versatile or something else. no idea

It is printed in white, then polished (put in a tumbler filled with small ceramic pieces, spinning for some time) then the prints are dyed.

Interesting, dye my own parts may be an alternative vs spray paint.

I've had similar experiences. Many of the items in my shop are designed to be held by retail action figures whose hands are essentially clips meant to hold 3mm bars. If the handle peg comes out as 3.5mm, that's a huge difference at this scale.

I don't understand the color process, did they paint it over white versatile or something else. no idea

The print it in white, then run it through a dye process to add the color.