{"id":808,"date":"2014-04-22T17:14:54","date_gmt":"2014-04-22T21:14:54","guid":{"rendered":"http:\/\/jmillerid.com\/wordpress\/?p=808"},"modified":"2014-04-22T17:14:54","modified_gmt":"2014-04-22T21:14:54","slug":"my-first-robot-part-2-3d-printed-tank-treads","status":"publish","type":"post","link":"https:\/\/www.jmillerid.com\/wordpress\/2014\/04\/my-first-robot-part-2-3d-printed-tank-treads\/","title":{"rendered":"My First Robot part 2 – 3d-printed tank treads"},"content":{"rendered":"

I found it surprisingly difficult to find just the right small-scale tank treads I wanted for Isabell’s robot, so naturally I looked into brewing-my-own. I first went down the RTV silicone path, but soon reeled it back\u00a0to reality… I want to get this off the ground soon, then maybe look into full custom treads for the next generation. So the following is an experiment, sort of a feasibility test for 3D-printed tank treads.<\/p>\n

\"rover_treads_2\"<\/a><\/p>\n

 <\/p>\n

This is really my first pass at a “tooth” design in CAD, based on nothing really. The cog teeth are simply arc sections meant to make the lead-in and lead-out smooth, and the tread profile is a rough approximation of the cog teeth.<\/p>\n

\"rover_treads_1\"<\/a><\/p>\n

 <\/p>\n

This is the result, using an FDM tread on a laser-cut acrylic wheel assembly. I actually made three different sized sets of wheels and picked the best fit, then measured and cut the rectangular parts to provide a decent pre-load on the tread. The whole thing is held together precariously with a couple of dowel pins (and comes apart quite easily).<\/p>\n

I had some concerns and they were mostly justified… The tread slips off the wheels easily after playing with the assembly for a couple of minutes, but that could be fixed with some retaining features. Also I suspected the tread would take a ‘set’ after sitting still for a couple of days– a function of the creep properties of ABS. Sure enough, a few days later I took the tread off and it had an elliptical shape, which I could feel in the form of on-again-off-again resistance when rolling the assembly along. I’ll bet a thinner-walled tread would be less prone to taking a set but still be strong enough to survive all the deformation. Ultimately I think the idea is feasible, but an RTV-cast silicone part would be my first choice for many reasons.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

I found it surprisingly difficult to find just the right small-scale tank treads I wanted for Isabell’s robot, so naturally I looked into brewing-my-own. I first went down the RTV silicone path, but soon reeled it back\u00a0to reality… I want to get this off the ground soon, then maybe look into full custom treads for […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[58],"tags":[51,62,60],"_links":{"self":[{"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/posts\/808"}],"collection":[{"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/comments?post=808"}],"version-history":[{"count":2,"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/posts\/808\/revisions"}],"predecessor-version":[{"id":810,"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/posts\/808\/revisions\/810"}],"wp:attachment":[{"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/media?parent=808"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/categories?post=808"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jmillerid.com\/wordpress\/wp-json\/wp\/v2\/tags?post=808"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}