I thought i solved the problem when I put a piece of tape on the headstock with the word LOCK on it. Naturally the tape came off over time and old habits returned.
Last week I came up with the idea to put a fridge magnet, coloured red, beside the switch when I have loosened the headstock lock. This reminds me to lock it before starting an operation. I then remove the magnet and only replace it when I loosen the lock. So far it works.
Now I only have to remember to use it.
Now back to the birdhouses.
John
PS: I tried to post a photo, but the file was too big. I will try to resize or take a new one later.