The trickiest part of building the slot mortising machinę is assembling the slider sandwich
First I laid out the parts of the sliders onto the wood to mark the hole positions through the holes drilled in the sliders.
Seeing that I didn not drill the mounting holes at regular intervals, I numbered all the parts.
The drawer slide halves need to be put together with the mounting screws and bali cages s. before mounting them onto the wood. They need to be installed onto the middle layer first.
Its quite tricky getting all the screws to hit their holes. I ended up putting a slight countersink in the holes in the plywood to help me assemble it morę easily.
Feel free to curse a little as you assemble this part.
I ended up temporarily putting nuts against the countersink screws, to keep the screw heads them from jamming up the sliders while assembling the sliders themselves.