Having assembled some components to make the Christmas Jack in the Box I started to 3D print the parts I wanted so that I could fix the servo motor inside the box so that it could open the lid. I hadn't used my 3D printer for a while and fresh from watching the recent Element14 webinar series on 3D printing I was in confident mood. It doesn't pay to be too confident as illustrated in the photograph below.



The melted white blob thing on the left is the first attempt at printing the lever which as you can see was not too successful. My UP! Mini has an internal light but it doesn't seem to turn on correctly so I had started the print before realising that it wasn't illuminating the printing. I didn't want to disturb the print so I just left it but I couldn't see what was happening. At that point in time I wanted my tea so I just left it going. . When it finished I excitedly looked inside (the light comes on when you open the door of the printer) and there was nothing there at all! Which was a bit disconcerting as it had definitely spent 20 minutes printing something. Then I noticed this white blob stuck to the print head. Luckily I was able to prise it away from the print head, seemingly with doing any damage. Subsequent prints have been OK so I think the print head is OK.


I tried again and managed to print out the correct lever without too many problems although this time I made sure I used a raft for the piece. I then printed out the base part which will hold the micro servo motor. Unfortunately the box I am using being wood and low cost is 69 mm by 70 mm and despite my multiple attempts to make sure I printed the base the correct way around, it was still wrong, so I had to sand down the 70 mm side to 69 mm so it would fit correctly into the box. I added the door opening lever and then realised that I had not taken into account the height of the box which is 73 mm. As the lever is only 60 mm long in order to fit inside the box when the lid is closed, it will not open the lid. This means that I will have to use a two part pivoted lever to open the lid. I had thought of doing that originally but then opted for what seemed a simpler approach.



I have found a digital record and play back module from a Christmas greeting tag that I purchased several years ago and I will see if this can be added to the Jack in the Box to provide some audible dimension. I also saw some battery LED Christmas lights on sale, which had wooden laser cut snowflakes which seemed suitable for the unfolding part so I bought those and disassembled them. The snowflakes are almost, but not quite, the correct size. Being slightly too large I will have to cut off all the points from the snow flakes, but I think it will still look OK.


Hopefully I will now be able to make a complete box lid opening mechanism so that I will then be able to concentrate on the glitz and glittery appearance.