I've put together a first draft of the alternate mechanism for the Dodo model. It works well for a first draft but I'll need to make a few changes.

For starters, I have to cut off the larger cam teeth as they were binding with the cam follower. I either need to move the teeth further round the cam or lift the cam follower so it is sloping down instead of up.

I've made some changes to the drawings and printed them out. I'll be putting them together in the morning. Its interesting, this!