{"id":32,"date":"2014-07-25T10:13:00","date_gmt":"2014-07-25T09:13:00","guid":{"rendered":"https:\/\/blog.hslracing.com\/3dprinters\/2014\/07\/25\/thread-less-lead-screws-with-no-backlash\/"},"modified":"2014-07-25T10:13:00","modified_gmt":"2014-07-25T09:13:00","slug":"thread-less-lead-screws-with-no-backlash","status":"publish","type":"post","link":"https:\/\/blog.hslracing.com\/3dprinters\/2014\/07\/thread-less-lead-screws-with-no-backlash.html","title":{"rendered":"Thread-less Lead Screws with no Backlash"},"content":{"rendered":"

I came across an item the other day on Thingiverse<\/a> that looked pretty interesting, that has huge possibilities for DIY CNC machines – that being a “thread-less ballscrew<\/a>” with zero backlash.<\/p>\n

<\/a><\/div>\n

There are a few other designs that have evolved this idea a little further, including another one<\/a> that uses cheap 608 skate bearings with 10mm rod and requires around 50lbs (23kg) of force to cause the nut to slip on the rod.<\/p>\n

<\/a><\/div>\n

This concept is certainly not new – on researching further, it would appear to be based on an idea that was originally patented<\/a> back in 1972 by Xerox Corp as a thread-less linear actuator.<\/p>\n

<\/a><\/div>\n

There are versions of this design commercially available today from the likes of Amacoil<\/a><\/p>\n

<\/a><\/div>\n

They even produce a model that has an adjustable pitch, which is produced by varying the angle of the bearings.<\/p>\n

More recently in 2011 Fengdong Zhao has further adapted and patented<\/a> a design to one that can even traverse a curved guide where the core of that guide is composed of strands of wire.<\/p>\n

<\/a><\/div>\n

He also includes a useful calculation for determining the lead pitch for the thread-less screw:<\/p>\n

tan \u03b8=L\/C where
\u03b8=angle of inclination
L = desired lead (inches of revolution)
C = circumference of drive shaft (in inches)<\/p>\n

The formula works just as well with mm, so to produce a lead of 1mm on a 10mm rod (the equivalent of M10 threaded rod), the angle of the bearings would need to be 5.71 degrees (atan(1\/10)=5.71 degrees), for a 2mm lead – 11.3 degrees and for a 3mm lead – 16.7 degrees.<\/p>\n","protected":false},"excerpt":{"rendered":"

I came across an item the other day on Thingiverse that looked pretty interesting, that has huge possibilities for DIY CNC machines – that being a “thread-less ballscrew” with zero backlash. There are a few other designs that have evolved this idea a little further, including another one that uses cheap 608 skate bearings with 10mm…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-32","post","type-post","status-publish","format-standard","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/posts\/32","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/comments?post=32"}],"version-history":[{"count":0,"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/posts\/32\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/media?parent=32"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/categories?post=32"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.hslracing.com\/3dprinters\/wp-json\/wp\/v2\/tags?post=32"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}