Thursday, 3 March 2011

FMP - Five (3/03/11)

Progress is moving quickly with the baseboard. Today marked the most important part of my model, the CAM, in that getting it into shape and attaching it to the base. After having figured out the circumference issue to get it perfectly wrapped round, I lasercut the hilly design in 6mm acrylic:

To transform it into a circle I needed to heatbent it, having learned the hard lessons of heatbending from the previous project, I made a negative and positive form for the job. Once the acrylic was flexible enough it was pushed into the negative former:

In order for it not to warp and cool back on itself the positive former was then pushed in:

I needed two formers due to the different diameters of the two CAMs. They were made in the same way as my base ring, that is using a router. Even though I had the correct length for these heatbent pieces, there is a gap where they meet due to the rounding down of circumference values when halving it; I tried filling it using the formers but it didn't work as well as I hoped, so I plan on doing this when they are attached in place.

I also made the supporting MDF cylinder for the mirrored part (as shown in the last update), which had to be at a set height so as not to be visible. The 25mm acrylic tubing sits on top of this block and then runs up inside of the mirrored part. 

It's important that the CAMs are in the correct position, or else everything above it goes to waste. To do this I lasercut styrene doughnuts as seen in the two below photos:

The outer/larger CAM is not yet attached due to a lack of styrene doughnut but this will be fixed in place tomorrow, and then both can be filled and sanded. Along with that I've also got to cut out the 0.5mm styrene runners which sit either side of both CAMs to prevent the wheels going off.

To end on a bad note I realised tonight, when assembling it that my lasercut pieces (the actual parts which rotate) were taken from an old model and as a result the holes cut out for the actual vertical poles which run over the CAM were out of place.

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