(Etymology of "Trouble at t'mill" For those of you outside of the UK)
I've been putting together the final parts version of the Giraffe as a check to make sure it all goes together properly. You can see here the three hangers that hold the various parts of the pendulum mechanism.
I've put grey areas on the block to which the hangers fit. You can just see the front ones here at the top and bottom of the block. The first hanger fits at the back. The position is shown here by the pink lines. The trouble is, the grey glue area is at the back obsured by the box back, I can't see it!
After much peering and squinting I've come up with a solution. I've used the blade from a bulldog clip as a mirror so that I can see what is going on then added a couple of small marks (arrowed) between which I'll be gluing the hanger. In the final project I'll add appropriate marks to the part itself.
This just goes to show how important this final stage of assembly/testing is. I quite often pick up and have to solve little problems like this, problems that are not at all obvious until you actually put the parts together as the end user will.