More Mechanism Development

On making a second laser cut maquette that had been modified I came across several problems. The main one was that the carrier kept getting stuck and wouldn't move upward no matter how much weight was used. After pondering the problem for a while and trying simple fix ideas I realised that the problem lay with the thread. My first maquette had wooden dowels which I was able to put small holes and secure the thread in place with. This second maquette had acrylic rod instead which was stronger but brittle for drilling holes through so I had simply tied the thread around each end and together with a knot. The problem was that this knot would have a tendency to move to whichever side the thread pivoted above (see above left). This in turn caused the carrier to move toward that side and get stuck. To solve this problem I decided to make a joining bracket which would still spread the weight of the carrier across the mechanism housing whilst allowing smooth upward movement. This was there was one thread giving lift to both guide rods (see above right).

 

 

This bracket seems to have solved the problem and the counter weight system works better than the first attempt. The images above show the mechanism at rest (left) followed by me lifting the weight as would occur when loading cards (center and right).  

I decided to test my own 'rubber texture' idea by making a silicon cast using a rough styrene guide. The silicon used was leftover from another student's job and I rushed together a rough mold (above) to make sure this was ready in time to use the following day (Friday).

The cast came out fine (below) and was trimmed down slightly to fit in the 'arm' section of the dispensing mechanism.

I used wire to secure the silicon in place on the arm (below) which would then be able to provide grip on the cards as it moved forward.

The arm worked well (see below) even on its return where the amount of friction was reduced by the shape of the silicon strip. I intend to make a more defined mold with slightly more ridges and cast it in black or grey pigment for the final piece.