Component Fabrication Attempt #19

--  Blue Foam - The Bane of My Existence --

OK, so that may be a little strong, but I had high hopes with what I could achieve in blue foam, all of which were dashed when I started using the hot wire cutter.  I thought it would operate a little bit more like a band saw, however it is not that accurate.  It must be noted that the first time I used the hot wire cutter it was shorting out at the top a little bit, and every time there was a spark the wire would cool and the cut would stop and this created errors.  This made cutting finger joints with the hot wire cutter next to impossible.

To cut the finger joints I attached one of the templates to either end of the foam and tried to run the wire between then to create a square cut.  However with a slightly faulty wire cutter this was far too inaccurate for my needs and I needed to come up with a different way of cutting them.

VERDICT:  FAILURE

Part of my idea with the blue foam was to loft between two slightly different shapes to create roof elements that gradually changed as they went around the roof.

This worked to a limited extent.  There was a certain amount of lofting success, however there were a number of times that the hand held hot wire cutter got caught and melted large areas that I didn't want to be melted.  I felt as though I could probably sort it out with a bit more time and practise, so long as I was able to sort out how to cut finger joints first.

VERDICT:  PARTIAL SUCCESS

My next attempt to cut finger joins was by hand.  I used a knife and a saw (which can be seen in the background) to hand carve the joints out.  I though that with this method I had more control, there would be not excessive melting and I could get a more right angled result.

This produced a better result, and I would say that 4 out of 5 of the finger joint cuts worked well, but it only took one poor cut to ruin an entire piece, and when I sliced it into the thin components, the errors were obvious.

VERDICT:  FAILURE

I then decided to clean and rethread the wire to try and solve the shorting out problem, which ended up working and eventually, after much frustration, I was able to get a consistent temperature out of the wire and a cleaner cut.  Having said this, not matter how clean I got the cut, it was still not a perfect finger joint and there was always the threat of human error slipping and melting part of the foam and ruining hours of hard work.

Old inaccurate cuts at the back.  New cleaner cuts at the front.

In the end I decided that although I could get something close to accurate out of the blue foam, it was not good enough for a 'super model', and I would have to cut the roof elements out of something else and also find room for bluefoam somewhere else in my model.

VERDICT:  PARTIAL SUCCESS