I've been deeply interested in robotic arms lately and have been researching and design a 6 axis one from scratch.
I have purchased a Labvolt Armdroid that uses 6 stepper motors for 5 DOF + gripper and it's not bad but more of a toy than a tool (other words adult toy) so want to build my own.
I'd like to see if anyone is interested out there to help.
My expertise and capabilities:
-math and programming, I will write most code in Matlab
-electronics layout (can mill my own boards and design the circuit)
-3d CAD drawing (Solidworks)
-CAM machining, almost anything 3 axis we can draw I can program with CAMworks to machine in about 5-10mins
Weaknesses that would like help:
-motor control (stepper voltages, currents, drives, etc)
-gearing
-material selection
Goals:
-FREE full open source 3d model is solidworks that can be machined/built easily from the assembly file
-free code to drive it
-almost every part will be able to be made easily on a 3 axis CNC machine with minimum tooling or bought from master.com
-mostly made of 1/4" AL plate to reduce cost
-easy to assemble/take apart
-anything that can be controlled in software rather than hardware will be
-2 to 4 ft reach at full extension
-6 to 10 lbs at full extension
-6 DOF
Intentions:
-minimize use of gears to reduce weight
-use stepper motors (cheaper and less gear requirements) and microstep them, 400 steps/rev, prob NEMA 23 - 34
-accuracy .001-.002" repeatable
-absolute encoder on all axes (stepper motor for easier control but need absolute encoder to get solid repeatable accuracy)
-code to translate the spherical coordinates to XYZ moves
-speed to be around 200-360 degrees/sec
-perhaps similar to CRS Robotics F3 ($60,000 robot) but bigger
-material cost under $2000 (realisticly it's not going to be super cheap, motors, drives and encoders aren't super cheap)
Rather than just building it and leaving everyone else on their own, I am building a detailed model for each part. Every plate, every hole, every screw will be added into the 3d solidworks model. You can freely move each axis/part to see how the set screw holds the motor bracket in place and view the range of motion, calculate the weight, etc.
I did some prelim drawing and made up a quick wrist design. I will post the solidworks assembly file to show the quality of the drawing. You can hide each plate and machine them individually.
Later on I will even include CAMWorks CAM data so you can just select the machine you want to it will pop out the set up sheets and G-Code to build your own robot.
End results:
-robot arm can pick up a tool and carve out a sculpture in 3d with many undercuts
-robot arm can hold things/weld/etc
-robot arm can pick up a rum bottle, pour it into a glass and shake you a martini