Oops! and I Mean Oops!
It seems to me lately that the spatial recognition neutrons in my brain have taken a vacation. I have missed numerous interferences that I usually notice when working up the CAD layout of the mechanism. This follower shown below is a classic. The follower in the foreground is the one that will swivel one of the eyes in the head. You can see that it doesn't not even sit down on the cam but is hung up on a pedestal in the right foreground. The same follower for the other eye a little further back in photo does not have this problem as the spacing allowed the similar pedestal on the other side to be placed further out.
The obvious fix is to cut enough of the counterweight off until the follower can sit on the lowest point on the cam. This may result in removing too much weight to allow the eye to be pivoted back into position by gravity. The first revision would be to extend the follower are far as possible to the right to replace the weight lost by cutting. At first glance the follower will remain fairly thin over the pedestal to work, so one of two other things may also be required. One is to shave the top of the pedestal, or add hidden metal weights in the extended follower, or both!
As much as thing mechanism seems large I have already had to redesign several pedestals, cams and shafts to fit things in, and yet I still find surprises like these. That is why a temporary assembly on a complex piece is always a good move. Now to throw out a few bits and make some new ones!
11/19/2019 10:59:04 am
Al, I'm always sorry to see anyone run into unexpected design challenges. As a solution to yours, could you cut off the interfering piece and attach a spring to hold the lever to the cam? The spring could be a weak one whose pull could be equal to the weight that is cut off. I'm sure you will overcome and adapt to the get to the solution. Can't wait to see it operate. Best of luck....
Leave a Reply.
Automata is a creative blend of my life interests , engineering, art and woodworking.