4dof robotic arm
Hardware- 18 Devlogs
- 44 Total hours
4 degree of freedom robot arm utilizing arduino uno plus a cnc shield to drive stepper motors with 3d printed gearboxes and components
4 degree of freedom robot arm utilizing arduino uno plus a cnc shield to drive stepper motors with 3d printed gearboxes and components
Added output to my psu, wired in buck converter, adjusted for correct output (5v) from my psu (24v), everything working other than 2/5 of my buck converters being faulty!
Spent time today working out a electronics housing, DH offset for parallel gripper, and added a simple marker gripper for POSCA markers for the arm demo, as well as bug fixes for control program **reminder all code written by either sonnet 5 or opus 4.8!
spent time today working on control of the gripper, decided on a separate microcontroller, a arduino nano, because of flash limits on the uno with gcobos/grbl4axis using like 97 percent of the memory on board!, using a separate COM connection with the app seems to work well, with built in PCA9685 detection. Also did a small amount of work on a case for all the electronics!
Finalized parallel gripper limit design, finally figured out how fusion fasteners worked (actually really easy!), Fixed E axis, and updated software for motion tuning!
Spent time today doing chores really in the cad files, like renaming all bodies and sketches to match their purpose for once, and also begin implementation of a sliding lock mechanism for the racks integrated into the parallel gripper!
Today I split time between getting my demo idea of the arm writing a word (suggestions for that?), getting a gripper design I actually like, and the tpu sleeves for said gripper. Stay tuned for more!
Today spent time editing cad models, starting design on a new gripper because the old one left a lot to be desired, and did more work on the arm’s demo once built! stay tuned
Updated control app with many things, biggest being pathing to different point smoothly, unfortunately live control of the arm via human is going to be an issue, fork of grbl I am using is limited by buffer, however pre-planned paths run smoothly enough hopefully, cant wait to get everything working on a real arm, just waiting on funding to hit (I’m out of filament :() **NOTE all code written by either sonnet 5 or opus 4.8
Working on control program for the arm! I have a custom ik and forward kinematic solver coupled with a gcode sender in order to send commands to a arduino uno running a fork of grbl, gcobos/grbl4axis! (what being special about it is using the A axis as another motor rather than extruder/ spindle) I was able to get all axis working (other than A but thats due to a faulty arduino D13 pin not working), all up on github!(NOTE** all code written by claude sonnet 5)
Spent time working on dh table parameters for inverse kinematics solving, anybody have good ideas for software to simulate the arm? Thanks!
Ok really tough session. After tons of testing several hours of debugging the A axis on my cnc shield wouldnt work, it wasnt the driver, socket, wire, or stepper, in the end I concluded that the arduino itself was faulty after many tests, I’m ordering a new one, but on the upside I did get a wiring diagram done!
Final fork support for wrist, started working on dimensions for inverse kinematics equations
Clearances for 3d printing, redimensioning base, and supporting joints to take pressure off of planetary gearboxes using a clevis fork like design off of bikes
also suggestions for the background color of the next render?
The gripper has been added. I went with a dual servo setup using 2 pretty standard servos and the actual gripper uses a really cool fish fin rib design where it automatically deforms around the object passively, at the tradeoff of maximum payload capacity, but you can change the gripper easily!
Finishing touches, final arm, rendering, preparing proposal for funding
Forearm added. Wow had a huge heart attack thinking i messed the whole design up and wasted an hour on a nonexistent problem, because of a mistake in initial dimensioning that would have ended up with the upper arm being completely straight up and down! Well first time making a robot arm so learning experience ig. other than cad i also tuned vref on all DRV88 stepper motor drivers with a demo link here https://www.youtube.com/shorts/iS-jFYrCbGg.
added upper arm and motor mount for forearm as well as fixing DRV stepper motor drivers and resoldering a new working fuse into the cnc shield
designing base and upper arm connector