My team just got the new 2 inch wheels and 2 rotation sensors to use for odometry but they are still shipping. I would like to know how to correctly build an odometry pod as there is very few resources online as all of them show encoder odometry. We have very few parts and little experience. Any help would be appreciated.
We just cut the middle of a 3 wide c-channel out and put 2 of the 2in Omnis offset in the middle. then put a bearing on one side and rotation sensor on the other.
Hi,
There are many ways of making an odom pod. If you are using 2in omnis, I suggest doubling up the wheels, then rotating one by 15deg (I’d check if that’s the right angle). This helps with 2in omni wheels being slightly polygon shaped.
I highly suggest using lasercut acetol for that actual pod that the wheels attach to. If you don’t have a laser or cnc (if you’re usint poly), then print out a 1:1 Cad of the part you want to make (can do this in fusion with the export drawing to pdf). Once you have the printed stencile, cut out a rough shape in poly, tape it to the stencile and sand until its smooth ish.
There are some common misconceptions about odom floating around recently. Odom can be run off of just the drivebase, there are no need for wheels. Wheels do improve accuracy, but they add weight, use ports, and get in the way (of things like hanging), so consider IME (internal motor encoder) Odom.
My suggested config for odom is horizontal if there’s only one wheel, horizontal and vertical if two. If you have three wheels somethings gone wrong, use a V5 Inertial for angle.
Last suggestion, try to join discords. People don’t commonly post their robots or parts of there robots on the vex forum. VCAD, VTOW, and Robolytics have huge communities and a stock pile of robots to look at. I’d send links but I’m not sure if thats allowed by moderators.
I wish you luck in your endevers,
Andrew
2131H Programming Dep.
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