Thursday, August 5, 2010

The Itch. Par Deux...

As I contemplated the "simple" modifications I've made on the Unicorn's knees, what I told myself bugged me to no end. I HAD TO extend the leg/knee joint to further increase the angle.

I thought of two things I can do; modify the already modified knee case by extending it downwards and giving it a new swivel point. It seemed easy enough, but the gears in my head somewhat got stuck on an obvious drawback to the solution; the extension will be unstable.

So, I have no recourse but to perform more plastic surgery on the leg connection itself. The solution is simple, but the process on how to do it wasn't because I would have to cut through enough material for the pla plate rebuilding to hold on to the ring that the knee case attaches to, and maintain enough area at the base. Simply cutting it laterally won't do it considering the section where the knee psychoframe slides, and I pondered for an hour what to do because I would have to "cut deep." I also hope my measurements are enough to give me at least 20 degrees more.

I cut through the base laterally with a thin saw (transparent white) so I can get the ring intact with enough material underneath (red). I then sawed off the rest of the part along the base line (blue), but this can only be fully removed by drilling the base of the cut (yellow).

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I then leveled of the excess material and rough areas with a knife and my old Tamiya flat screw driver which I used as a rudimentary blunt chisel. I initially planned to do just one knee for demonstration purposes, but realized that I had alignment issues to consider, so, I alternately worked on one while waiting for the other part to cure.

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I worked on one ring first and using that as as a reference for symmetry. I used 1.0mm plaplates to extend the base, and 0.5mm to sandwich the extension and the base, adding 0.3mm plapates to compensate for unevenness and to provide bulk so that the rebuilt part fits snugly when it is reconnected to the base. I overcut the edge of the extension, but since this is easily remedied with a piece 1.0mm plaplate, trimmed to the size of the part's base (left).

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I used the rings themselves to align the parts with one another so I can trim the fresh build into shape (note: I did this faster than I'm supposed to, and the plates have a tendency to come loose of even bend because of the cement softening it, but I have anticipated that though experience with cement use. It's always better to work on cemented parts after at least a few (ideally 24) hours or when the structure has solidified).  I've also reinforced the structure with a lateral plug (lower right) that should help hold the sandwiched together with the ring.

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In certain cases where I have to work fast, I clamp sandwiched parts for an hour or so to let the curing parts merge a bit faster. Since I don't have C-clamps like DC, I use medium-sized double pins instead. These are pretty cheap at Daiso/Uncle Bills/Japan Home, and are also nifty painting implements.

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To reinforce the modification, I used that section of the leg frame where the armor frame connects to. The armor frame has two other connective sections so I can sacrifice half and half of this pair to insert a plug that would hopefully hold the rebuilt ring to the leg/knee base. I drilled a hole through and through, inserted a round pla beam plug, and dropped extra thin cement into the hole, letting capillary action do the job for me.

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The plugged (left), and unplugged sections.

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As of this post, the sandwiched parts are still soft and bendable, so I won't risk a test fit until they've fully cured.

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