Nice HIPS

After a long time off building, the last weekend was spent making the half moon details for the outer feet. It was my first attempt at using styrene, or High Impact Poly Styrene if you want to be technical, or HIPS if you want to be technical and laconic. After using it for the first time, I was pleased at how easy it is to work with and how well the parts came out.

First off, I printed out full scale templates on to some A4 sticky labels. This is much easier and more accurate than trying to reproduce the plans by hand. The parts were cut out individually and stuck to the thin, plastic coating used to protect the styrene so that it would come off easily later on. Some parts needed to be thicker than others, so 1mm and 3mm styrene sheets were used.  

The parts were rough cut to smaller pieces using a small saw blade attached to the Dremel.

 

The next step was to cut the pieces out to their actual size. Starting with the 1mm parts, I used a steel ruler and a retractable knife and scored along the lines repeatedly until it cut through. It took some time, but the results were good. 1mm curved edges were done with a pair of scissors.

 

 

 

Cutting out the 3mm parts using this technique sounded like a really bad idea. The 1mm parts took a long time so I needed a better solution. The Dremel wouldn’t give as clean an edge and neither would a saw. Maybe the knife was right, but my technique wasn’t, so it was off the bench and onto the floor. Sitting at a table, the job was in front of me, so applying downward force wasn’t efficient. On the floor, the job was below me and I was able to put more weight behind the blade.

 

Once the cut was started, the ruler got benched and brawn took over. The end result yielded great edges that were super accurate. The curved 3mm pieces needed some shaping. I made up a small jig to make sure they all sat square with each other, put them all in the vice together. I used a dreadnaught file to get rid of the bulk and a smooth file to finish them off.

 

 

 

 

The pieces were now ready to be stuck together. I used M.E.K, or Methyl Ethyl Ketone if you want to be technical again. This stuff welds the styrene together. I just used a pencil brush to apply it to both surfaces, gave it a few seconds to set and then held the parts in place. It took no time for the parts to bond and form a really strong joint.

 

 

 

 

After the main structure was assembled, I had to skin the upper edge. Before I glued it, I curved the piece into shape just by bending it back on itself. The 1mm styrene is pretty malleable.

 

 

 

 

 

The parts were left to cure for a while and then I filed back the upper edges to clean up the join. The pieces look like they’ve just come out of a mould. Now they’re ready to be primed, sanded and painted.

 

 

 

Two coats of sandable primer were sprayed on…

 

 

 

 

 

 

…and then sanded back with a sanding block. They’re now ready to be painted.

 

 

 

 

I’ll need another pair of these for the centre foot and I’d be happy to make these again, but may try moulding if I feel adventurous.