40$ SCARA Arm

thingiverse

This robotic arm is an excellent base for programming projects. Considering its affordability, priced under $40, it's remarkable how much strength it can support. The choice of materials was driven by my desire to utilize components I had on hand, which explains why reed sensors and $3 stepper motors were selected. The top plate ("top.stl") is suitable for both a stepper and a 360 servo to handle Z movement. If you're using a servo, you'll also need to print the rev counter (“rev_counter.stl”) and install an extra magnet and an additional reed sensor. On the other hand, if you opt for a stepper, you'll only require an extra coupler. For convenience's sake, I recommend the second solution, as it's also simpler to program. I intentionally left a thread hole at the end of the arm to allow users to design their own modules and share them with the community. To maximize performance, I suggest converting the steppers to bipolar function, which will provide more torque and enable direct integration with Arduino RepRap and CNC boards. To accomplish this, follow the tutorial available here: https://www.youtube.com/watch?v=sY1Y_BJ-fTQ . Unfortunately, I didn't develop any demo program, as I'm not fond of programming. If you appreciate this model and wish to see it in action, please write some lines of code and share your work. If you have any questions or concerns about the assembly process, feel free to leave a comment, and I'll respond promptly. If there's sufficient interest, I may create a video tutorial to address these questions. Materials: - 3x 8mm steel bars (choose your desired length) - 1x M6 threaded bar - 6x M6 nuts - 12x M4 nuts - 2x M4 25mm screws - 9x M4 20mm screws - 34x 8mm steel balls (available at http://www.dx.com/p/8mm-carbon-steel-slingshot-ball-silver-47-pcs-258609) - 2x M3 plastic screws - 1x M4 50mm screw - 2x 22mm bearing (find it at http://www.dx.com/p/ec-hbcs-7-high-carbon-steel-skateboard-bearings-set-silver-8pcs-428675) - 6x 8mm linear bearing (available at http://www.dx.com/p/n-linear-ball-bearings-silver-10-pcs-468551) - 1x 7mm x 20mm spring - 1x button (find it at http://www.dx.com/p/plastic-copper-push-button-power-switches-red-10-pcs-153209) - 1x micro bearing (available at http://www.dx.com/p/rc-axial-1-10-scx10-jeep-wrangler-bearing-5-x-11-x-4mm-10p-418705) Configuration 1: - 3x reed sensor (find it at http://www.dx.com/p/mini-arduino-magnetic-detection-sensor-module-black-135504) - 3x 6mm magnets (available at http://www.dx.com/p/d12-6mm-cylindrical-strong-ndfeb-magnet-silver-20-pcs-450996) - 2 stepper motors (find them at http://www.dx.com/p/28ybt-48-dc-5v-stepper-motor-uln2003-driver-447220) - 1x 360 servo motor (available at http://www.dx.com/p/360-degree-rotary-steering-engine-black-121328) Configuration 2: - 2x reed sensor (find it at http://www.dx.com/p/mini-arduino-magnetic-detection-sensor-module-black-135504) - 2x magnets (available at http://www.dx.com/p/d12-6mm-cylindrical-strong-ndfeb-magnet-silver-20-pcs-450996) - 3x stepper motors (find them at http://www.dx.com/p/28ybt-48-dc-5v-stepper-motor-uln2003-driver-447220) - 1x coupler (available at http://www.dx.com/p/winding-thread-elastic-top-wire-coupling-aperture-10-x-10mm-silver-467421)