Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: mdmedlin on April 23, 2009, 03:55:37 AM

Title: wheel tutorial
Post by: mdmedlin on April 23, 2009, 03:55:37 AM
So in the wheels post, I mentioned how I had made some lexan wheels.  Lexan is a name brand for polycarbonate plastic sheets.  They are tough and durible.  I wanted to write this so that other members that did not read the post can maybe see some of the things that I did and maybe use them themselves.   ;D  Well I found that Mcmaster-carr will sell 1/4 inch belting by the foot, so you can basically make the wheel as large as you want and still be able to apply the traction control that I was talking about.  The link for the mcmaster site is here: ( I used the singel sided with the trapazoidal teeth.  What you use is entirely up to you.  The belts that I used were already prejoined and that is why I had to use a mill and mill down a piece of plastic to the right diameter so that I could put the belt in it.  They have various sizes, that way if you have large wheels, you can get larger belt and have the added traction.  I am not sure how they will hold up on rough dirt terrain, but it is a viable option.  I also had the idea that if you used a mirrored plastic wheel with the mirror on the inside, you could use like a photoeye or some other decector and draw a line on the wheel if you need to monitor the number of revolutions.  I found mirrored plastic on this site: (  unfortunately they only come in 1/8 and 1/4 inch sheets, but the possibilities are boundless!!!  When you use a mill to make the circles, you have to center the piece on the chuck.  What I used was a socket headed capscrew and used the centering tool pressed into the screw to make sure it was center.  Then I milled it down and viola, I had a nifty wheel.  I screwed the horn for the servo into the wheel itself.  That way it would turn duh!!!  If you have any questions, I will check this post and try to answer them.  I think that the sheets are resonable priced, but for those on a budget, I guess you could use a file and file the edges of the plastic away until you got to the circle you wanted.