this has been a rough week, with the realisation after few hrs of fiddling that the current ‘follower’ setup cannot work with the highly irregular shapes I had produced 2 weeks before. So for now I am focused on using circles with an offset center, and produce some motion and adapt the original idea to output something visually interesting for the final.

spring tests

my idealised version of leverage system

leverage test for magnifying movement

the springs are needed to bring the followers down in contact with the cam, but it’s a tricky business of balancing the strength of the spring vs the load. More experimentation time is required, which unfortunately is quickly running out.

wax helps a lot!

When the simple circles were first installed, it did not work at all. the followers were stuck. thankfully, copious wax on both cam and follower helped everything moved along.

3 test cams & added supports in the middle

after the setbacks, I decided it is best I break down the process to incremental, simpler steps and also to avoid wasting hours on producing unusable parts.

added top braces and hooks for strings

after getting 3 cams to work reasonably reliably, I placed some loads and setup the basic braces to get ready for attaching the cloth.

last week has been a roller coaster ride of sorts, first realising the original cam shapes had to be abandoned, and later the leverage mechanism I had imagined was much harder to put in practice.

also, the prototype I had constructed had too many differences from this final model. everything, from the main shaft length, follower lengths, size and shape of cams played a factor in whether it will work. the leveraging system was also non-trivial to achieve, at least with my amount of inexperience.

but all in all, I think it was a good lesson for me as all this(automata and mechanical construction) has been very new and refreshing for me, and it definitely required a change of mindset and perspective from traditional woodworking.