EZ Print Modular Robot Arm

pinshape

Summary Updates! 3/26/17- I've uploaded the Arduino sketch that controls this joint. The improvements include calculations when the joint reaches a point and determining all angles before moving. Homing is done by moving the joint to its max left position then max right, allowing the stepper to skip steps until centered. I used 1/4 stepping on my stepper driver for this. 3/18/17- I revised the Rotating Base at http://www.thingiverse.com/thing:2186716 3/15/17- Check out my new Youtube video at https://www.youtube.com/watch?v=_ZqThKUGIBc&feature=youtu.be 3/14/17- I uploaded the Arduino Program that controls this joint, using inverse kinematics to determine J3's position from XYZ. 3/12/17- V3 parts have a chamfered hole for pins, eliminating extra material that needs removal. 3/9/17- V2 fixes issues with clearance between ring gears and holders. I made the holders .1mm smaller, leaving .1 of clearance between the gear and holder. I included the Fusion 360 Project with this: The Gearbox (43.33 :1) is a separate "thing" at http://www.thingiverse.com/thing:2101218. This gearbox is necessary for the joint as it not only drives but also provides a bearing, using Emmets "Gear Bearing" concept. Most of the pieces in the actual assembly picture are from the prototyping stages. The design I'm uploading now uses white prints. This Thing is a redesign of http://www.thingiverse.com/thing:2105057 and requires 2X - 4mm thread bolts or 2X- 6/32's. The gearbox and joint setup has very little backlash, maybe 1 degree when printed correctly. Running the gearbox without it pressed into the arm is a good way to wear it in but can also take the planet gears out of alignment if the rings open up and skip a gear. I designed the gearbox with an optional 4th ring and 4 module planet gears for extra support against side to side play and reduced backlash. For this, you'll need to print the Optional 4th Module Holder.STL file from this "thing". All parts are stackable and fully compatible with the old design and the gearbox in the link. This arm rotates 230 degrees before colliding with itself in the cad program but is actually more like 229 degrees real life. Feel free to create your own joints and attachments for this project! Oh yeah, if you print this, would you kindly post a make with a picture or video? Please and thank you!