So having done the farm chores (including moving all the chicken into a sealed polytunnel due to the threat of Bird Flu H5N8 * ) I could get on with aligning the slat supports.
I set them so the top of the slat / bottom of cutting victim is 5 mm above the side rails for no reason other than it seemed sensible that they receive the sheet when being initially loaded rather than the side rails - previously they'd been a couple of mm below the rails. If it proves to be a wrong decision it is easily reversed as they mount on adjusting slots.
Having got to this stage it was time to insert a catching mesh - it will be a pain if little bits that you want fall between the slats and have to be fished out through the clearing door - at least with a mesh they can be recovered with a 'magnet on a stick' fairly easily. I'm not certain that this mesh will be entirely satisfactory as I fear that it might impede air flow too much. It just sits in so is easily replaceable - it started off as a one metre square of galvanised expanded mesh and I turned up the edges 25 mm to stiffen it a bit. (Actually it started as a full 1250 x 2500 mm sheet that was great fun manipulating single handed - amazing how often it catches on things including clothing
Right ho - time to trim those slats - no wait a minute, the whole idea about adding a third support rail for the slats was to curve them, which will reduce the 'chord length' - but how much. Answer - by just the right amount
So the acceptable original slats have been returned to service along with seven new ones to replace the unacceptables.
Now I need to plot and scheme how things will be laid out in the electrical enclosure - I'm umming and arhing about whether to direct hard wire motors and sensors into the cabinet, or the use plugs and sockets. My thought at the moment is that there is no great benefit to the plugs and sockets, and its another thing to fail in the future. I intend to bring all wiring into the cabinet and first to a 'DIN rail mounted terminal strip' which will give an easy point of disconnection and also useful for test purposes.