steelead
commented
8 years ago I think there are two ways we could do this.
I couldn't find any straight up mount that provides us with a ball joint to connect some sort of rod onto, but I found this video (https://www.youtube.com/watch?v=ZrZodwEHjew) using threaded ball links (we could get from servocity: https://www.servocity.com/html/2-56_threaded_ball_link.html). Now he connects them straight into the board on the side, but I don't think we will be able to do that, and instead we will be mounting them to the underside of the table, so we should use one of these mounting brackets: https://www.servocity.com/html/mounting_brackets.html (either clear hole or threaded - threaded might be better since they have some which have two screw holes for inserting into the table to prevent it from rotating over time).
The second way is to use two more ball linkages (that we are already connecting from the servo horn/arm to the threaded rod: https://www.servocity.com/html/ball_linkages.html). This will provide us with a little less rotation, but I think it should work fine as there are a few other examples that use this method (https://www.youtube.com/watch?v=j4OmVLc_oDw, https://www.youtube.com/watch?v=enlQMUE9df4). While they don't have as much rotation ability as the first method, they can still rotate (probably) enough (https://www.youtube.com/watch?v=gBVLrDIJKAE&feature=youtu.be&t=11m10s). Again, for mounting it onto the table, we could use mounting brackets, or we could use the beam crossover adapters we picked out earlier (https://www.servocity.com/html/beam_crossover_adaptor_a__5854.html#.VjB_JLerRhE)
One last issue I was looking at is the length of the threaded rod (2-56 version), all of the stores I looked at online only had minimum lengths of 12 inches, with variable lengths scaling up from there. That seems pretty long, will we be able to cut those to the correct length we need them, or is there somewhere that we can buy some at the precise length we need them at?
We need a new design for the way servos attach to the bottom of the table. It must allow the connection to turn on both the X and Y axis.
NOTE: some useful keywords are "Ball and Socket Joint" and "Ball Pivot"