robotic arm

Put all the mounts for the magnets and hall effect sensors on the main parts so less printing and no glueing is needed. Posting devlogs more frequently now

Im going to upgrade the stepper of joint 1 from a nema14 to a nema17. The nema14 just didnt have enough torque to spin the arm without shaking a lot and skipping like half of the steps… This is the new motor case for mounting it. It will now have the lower bearing cap attached to it for easyer printing and assembly. Also finished installing and connecting all the hall effect sensors to the arm and every joint is homeable now! Next will be installing the new motor and then calibrating the software and if everything goes according to plan (it wont) i’ll be done!!

Did a cfd analysis of the housing for my arduino and the cnc shield. It was pretty hard to figure out but also very fun and most of all a valuable skill to learn. This might be a bit overkill but it actually helped me improve the case for better airflow over the heatsinks of the motor drivers to ensure keeping them cool for when the arm will be working for longer periods of time and under higher loads. For anyone interested I did this in Simscale its very easy to use and you get 10 free simulations!

Worked a lot on the homing of my arm. Did a lot of software first off. Adding the homing buttons to the GUI, adding the commands which will be send to the arduino and adding the homing feature on the arduino itself were a lot of work but we got there in the end! Also added a section for error messages and stuff at the bottom. For the hardware side I glued all the hall effect sensor in place along with the magnets needed for the sensors. I glued them on but i plan on putting designated spots on the arm for the magnets and sensors so you wont have to glue them on if you decide to build the arm yourself. I then had to build a small board to allow all the sensors to recieve power from the cnc shield. I now also started connecting all the sensors to the arduino which takes a lot longer than expected actually. But ive been successful so far and both of the connected joints work as intended right now. Next up i have to finish connecting everything and then finish so software side so the arms get to the correct position once they’re homed. This is a lot for one devlog but its hard to define clear borders in this project since everything is connected with everything else so you are never “done” with one subproject because its only a small part and wont work without me working on the next thing. Also didnt add any pics of the arm with the sensors since you cant really notice a difference compared to the older photo on here except a few more wires…

I cant belive I’m typing this, but it works. After intensively working on the software side the last few days while waiting for the last hardware pieces needed I assembled everything today. I put on the jumper caps to enable microstepping and installed the new cables for joint 3. When everything was done i just had to do a tiny bit of troubleshooting but after that it just worked! I can control all the joints and the software also doesnt really have any issues. The only thing that doesn’t fully work yet is the target point feature, since i cant home the arm yet. Some magnets will arrive in a few days and i’ll use them with hall effect sensors to home the arm. Then it’ll hopfuly work just as it should and i can get to documenting this whole thing for you guys!

Advanced the software side quite a bit. Waiting for some new parts rn so I used the time to finish the gui for now and calculate everything i need to to send to the arduino! You can now input the three values making up the target point and hit calculate. Then the angles of the three joints relative to their home position as well as the delta of the angles, which is the value which the joints need to move in order to reach the target position, are displayed below. These are the values which are going to be send to the arduino. I also added the function to ignore physically impossible positions of the arm and only show the possible ones. In theory I only have to add some kind of interface to send data to the arduino and the software would be done!

Wrote the code to controll all 3 joints.did this to prepare and pass time while i wait for my cnc shield. once it arrives ill hopefully be able to fully control my arm for the first time ever!
No new features (apart from the 3rd joint) where added, but i cleaned up the code from the last version a bit and removed some unused sections. I also added lots of comments to make editing and extending the code easier in the future.

New Joint 1 -> Base interface without wobbling like the one before.