Once I decided on the form to refine, I had to make a full scale model so that I could judge its dimensions correctly. The full scale model can be seen below. I made this model using the edited “leg” design from previous posts.
After creating the full scale model I decided to start developing a backing plate for it, the purpose of this backing plate was to hold the form together, work as a storage space for the electrical and be a hanging mechanism for the clock. The first backing plate I made had a nail slot and usb entrance hole that was way too large.
I also only allowed tolerance on the width of the spokes which made the back quite hard to get on.
The next backing plate I made I allowed tolerance in both directions and it was a lot more successful.
I also decreased the size of the hanging slot and it is now good. However the usb hole is too small now (10mm) and needs to be increased to 15mm.
Photographs of backing plate working below.
For the acrylic final model I had to test the tolerance needed to allow the acrylic to easily slot together like the cardboard did. My first set of tolerances I checked no tolerance to 0.75. No tolerance was much too large meaning I would have to look into negative tolerances.
negative tolerances 
no tolerance slot being measured, should read 30mm 
positive tolerances
I then did the negative tolerances rated no tolerance to -0.40, I found that -0.30 was the best fit as -0.40 would not fit at all. I will therefore use the -0.30 as my slot tolerance for my acrylic form.
Elizabeth Dean 