3D Printing The Parts

Back To The Future Mr Fusion – Printing the parts

This page is about printing the parts for my replica Mr Fusion build – the ‘home energy reactor’ which powers the Delorean in BTTF 2. Click here for the main project index.

There’s a YouTube video about this

The base from Mr Fusion which I drew in the last part is too big to fit in my 3D printer, so I’ve sliced all the pieces up using Autodesk 123D Design – I’ve cut it into eight sections, and each of those into two. The pieces will printed one by one and then reassembled in real life.

Some of the pieces have splits in where the plastic has shrunk is it’s cooled and the layers have separated. I’ve found this is worse if I print both pieces of one eighth together, probably because the previous layer has more chance too cool before the next layer is applied – this cooling time is reduced if one sixteenth is printed at a time, so the prints are better quality.

All the pieces are printed in ABS, they are chemically welded together with acetone. I could have stopped shrinkage if I had printed them in PLA, however these pieces would not dissolve in acetone so I would need to use glue to stick them. Acetone can also be used to smooth out imperfections in ABS pieces, but not with PLA.

Three eighths together:

Some parts are a bit more tricky to slice than others. Picture on the right is five eighths, so now it’s time for the three unique sections that fit between them:

After finally printing all the pieces and assembling them, I painted the piece with two coats of shed roof sealer in an attempt to cover the build lines. I’ve then sprayed it with Satin pain. I could of course have used Acetone Vapour Bath smoothing, but the piece is quite large so this is a challenge:

Here’s the start of the lid, which is again sliced into 8 sections:

And the whole lid together:

The lid has been placed in a sealed container with some acetone, the acetone vapour eats away at the surface and makes it all smooth and glossy – no sanding involved!. The seam lines you can see are because the pieces is now slightly translucent, but it’ll be painted with plastic primer and gloss white automotive paint.

I cleaned the original logo off the Krups 223 using T-cut, and painted my lid white with ‘appliance white’:

Check out Page 3 for the finished pictures.