Ingredients
2 3.6 m yellow battens
4 4 x 40mm screws
24 4 x 50mm screws
Tools
Electric drill (I always drill pilot holes for my screws) with 2.5mm bit.
Electric screwdriver
Electric mitre saw
(Jig)saw
Small spirit level
Tape measure
Straight edge
Pencil
The framework for the plant theatre is fairly straightforward; each end is as in the diagram shown.
One end of the 115.5 cm strut needs to be cut at 30° across and the other at 60°. The 60° is to fit flush on the 1 m vertical and the 30° is to sit flat on the ground. One end of each of the 19.6, 37.0 and 54.3 cm struts are also to be cut at 30° to fit flush against the inside of the oblique strut. If the cuts are done accurately the bottom shelf will be 5cm off the ground. The cuts 30° from straight across are easy enough with a itre saw but the “sharp end” needs a (jig)saw as it is beyond the settings of a mitre saw. Mark a spot 44mm (if the batten is not 22mm thick just make sure that the mark is twice as far down the batten as the batten is thick) from the top of the front support along its back edge and draw a line from this mark, across the 22mm face, to the top front corner (see below). Fix the batten in place and cut along this line to get the correct angle at the top of the front support. Make sure your cuts are both on the same side of the batten.
The back ends of the shelf supports should be cut square but the front ends should be cut at 30o. When putting the frames together fix the tops together with two 40mm screws while, if you can, holding the bottom shelf supports in place. I do it with everything lying down on a work bench and using bungee cords and clamps to hold things in place although I believe there are now special clamps to hold wood joints in place while you screw them together. Fix the bottom shelf supports in place using two 50mm screws at each end. It is probably best to do this with the front and back supports standing up so that you can use a spirit level to make sure the shelf support is horizontal. Measure the position of the fixing point on the back support, fix the shelf support to it and then balance the spirit level on the shelf support to find the fixing point on the front support. To make sure the shelf supports at each end of the plant theatre are at the same height I stand the end frames side by side to fix the shelf support on the other end-frame.
In theory if you measure and cut perfectly (something I have never managed to do) the palaver with the spirit level should not be necessary. By measuring down the front of the front support strut and making marks at the following points: 39.3, 73.9 and 109.7cm with further marks 2.5cm below each of them you should mark the top and bottom of each shelf support. My measuring and cutting are never good enough to do it that way so I have to use the spirit level method.