I picked up some more shim foil from Shaltz and cut a strip to fit the gear.\u00a0 It was much easier the second time around – I just rolled up the foil, inserted it into the hole in the gear, then slid it onto the shaft of the motor and tightened the set screw.\u00a0 The system works fine with the new shim.<\/p>\n
I did discover why the first shim failed, because it started happening again.\u00a0 After attaching the pendulum and doing a simple sine motion for a while, I noticed some spikes in the PID output at zero speed points.\u00a0 I thought they were caused by the pendulum swinging, because I saw them shortly before the shim self destructed the other day.\u00a0 To be sure, I removed the pendulum but they stayed there.\u00a0 Pretty soon I realized the set screw was loose, even though I had it nice and tight about ten minutes earlier.\u00a0 It came loose a few more times while I was running the pendulum, so I need a more permanent solution.\u00a0 I am thinking either superglue or lock-tite.\u00a0 I suspect superglue might be a little more permanent than I like.<\/p>\n
The good new is that the motion of the pendulum does not appear to\u00a0affect the motion of the cart.\u00a0 As far as I could tell, no matter how much the pendulum was swinging, the cart tracked a sine wave very well.\u00a0 I tried both position and speed control, and both worked well.\u00a0 The feedforward portion of the control does most of the work, and the PID feedback provides the corrections to keep it on track.\u00a0 I did notice more PID output while the pendulum was swinging, so I will probably need to figure out how to model it to have an accurate model of the entire system.<\/p>\n","protected":false},"excerpt":{"rendered":"
I picked up some more shim foil from Shaltz and cut a strip to fit the gear.\u00a0 It was much easier the second time around – I just rolled up the foil, inserted it into the hole in the gear, then slid it onto the shaft of the motor and tightened the set screw.\u00a0 The […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-191","post","type-post","status-publish","format-standard","hentry","category-software"],"_links":{"self":[{"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/posts\/191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/comments?post=191"}],"version-history":[{"count":2,"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/posts\/191\/revisions"}],"predecessor-version":[{"id":193,"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/posts\/191\/revisions\/193"}],"wp:attachment":[{"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/media?parent=191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/categories?post=191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ammonsengineering.com\/blog\/wp-json\/wp\/v2\/tags?post=191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}