I modified the two Y screws on HB2 this evening. I removed the axis screws\u00a0completely from the machine and chucked them (one at a time) into my Proxxon PD400 lathe. I cut back the 0.250″ diameter shafts at each end an additional 0.063″ – 0.065″ to make space for the 1\/16″ thick 1\/4″\u00a0x 5\/8″ hard bronze\u00a0thrust washers. I also made sure the screw\u00a0shoulder was absolutely flat to the washer and square to the shaft.<\/p>\n
I reassembled all four\u00a0Y axis ball\u00a0bearings (new) with a hard bronze thrust bearing (Alloy 932, sae 660)\u00a0between the shaft and the ball bearing. The flat thrust bearings (McMaster-Carr 7814K11)<\/a>\u00a0cost $2.52 each so they were not cheap. I chose them because they are rated to take sudden loads without wear or damage<\/a>. Exactly what happens in a rapidly and constantly\u00a0reversing CNC machine.<\/p>\n The improvement in the Y axis operation is amazing! It runs like a totally different machine. I can do 150 IPM rapids (750 RPM) without weird sounds. I don’t trust it that fast so rapids are now set back\u00a0at 125 FPM (625 RPM). Still louder than the X axis at the same speed\u00a0but\u00a0so wonderfully smooth sounding again.\u00a0<\/p>\n I’ll take some pictures of the X screw rebuid to show what I did. That change out is next.\u00a0It will be the same detail as how I did the Y screws. The addition of thrust bearings is certainly worth the slight effort and cost.<\/p>\n I may stop thinking about the motor resonance unless that is what’s limiting me to under 600 rpm. It’s really a non issue as I don’t cut anywhere near those speeds.<\/p>\n","protected":false},"excerpt":{"rendered":" I modified the two Y screws on HB2 this evening. I removed the axis screws\u00a0completely from the machine and chucked them (one at a time) into my Proxxon PD400 lathe. I cut back the 0.250″ diameter shafts at each end an additional 0.063″ – 0.065″ to make space for the 1\/16″ thick 1\/4″\u00a0x 5\/8″ hard […]<\/p>\n","protected":false},"author":77778,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[35],"tags":[138,139,24,57],"class_list":["post-989","post","type-post","status-publish","format-standard","hentry","category-home-brew-2","tag-cnc","tag-hb2","tag-machine","tag-steppers"],"_links":{"self":[{"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=\/wp\/v2\/posts\/989","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=\/wp\/v2\/users\/77778"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=989"}],"version-history":[{"count":0,"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=\/wp\/v2\/posts\/989\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=989"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=989"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.thehobbyistmachineshop.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}