The opportunity has arisen for obtaining some 40x40 Alu profile - due thanks will be given in time if it works out! The original design I was considering used a slightly different size so I would like to invite comment on some newer design ideas.

Following image is a "quicky", showing only part of the frame. I didn't model the aluminium so they look like basic bars in the image. Plates are made transparent but the location still shows up.

Simple fixed gantry, lower end of ganty "leg" supported on either side by the profile used for the side wall and the whole thing braced with a piece of aluminium plate:

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Any major structural problems? Any effective (and cheap!) ways of increasing rigidity? The sidewall has another piece running along the inside at the bottom, you can just see the end in the picture - this would be for a rail.

The gantry itself has the crosspieces mounted on the front of the supporting "leg". In the original plan I was going to put then in line with the gantry leg and have plate on the front and back. Example below:

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X/Y is planned as minimum 300mm working area, so gantry crosspiece is pencilled in as 500mm, long Y rail is pencilled in as 800mm-ish.

Some kind of L-brackets where the gantry leg meets the lower long rails? Where the bottom cross-piece meets the gantry leg? I'm not adverse to a little overkill if I can afford it