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Sunday, August 14, 2005

The Two-Step

The RepRap Meccano prototype turntable is now mounted back on the rails, using small pulley wheels rather than Polymorph sliders. A sensor magnet has been added to the turntable together with a reed switch on the carriage (blue & white wire), and a limit switch to the right-hand end of the rails (green and white wire):



A "GO!" switch (red & black wire, also front panel) has been added to allow visitors to initiate actions while I'm showing off. Actually, it's a little more useful than that; I've added a sync sequence to locate the limit switch and reposition the carriage in the centre of the rails at the same location each time the power is applied. I'll then be able to conduct a manual arming sequence for the extrusion head and start it going when I'm good and ready.

This also has the convenient side effect of moving the carriage to the far left whenever the power is cycled. Handy for getting it out from under the deposition head to clean the turntable or extract an artifact.

The white tube dangling from the extruder only contains a fat marker pen. It does not contain mice, despite the opinion of my furry feline companion Chad. The marker is used to show that the track followed is consistent, at least in 2 dimensions. Adding the vertical axis control is relatively trivial, but will involve getting another PIC going 'cos I've just run out of I/O pins. Syncing it all up is a more intricate software problem.

Suz had set the task of drawing an oval as something that would impress her, and guess what? It now draws ovals at the press of a button. We figure we're not to far off producing a RepRap logo now :)

No RS232 still. Adrian has given me his code, but I've been too busy tidying things up and drawing ovals to do the relatively simple code import. The breadboard area is much tidier though, with plugs fitted to many wires thus ensuring they don't get knocked out by fiddling experimenters or wandering cats. It might seem picky, but it leads to more repeatable experiments and more reliable results.

Vik :v)

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