When:Β 28 June 2019, 1pm
Members present: All
LA-Tubing Connector Mk III
LA-Tubing Connector Mk III.
The new LA-Tubing Connector Mk III finally printed out, and it was a perfect fit onto the piston head. It was even satisfying putting it on.
(Almost) Complete Prototype Testing #2
We decided to test it out and run it with our Arduino code. Previously, when we tried this, it began to jam and make a loud noise. We guessed that this was due to the misalignment of the LA piston head to the profile-tubing connector. We made revisions to the respective designs for better alignment. Unfortunately, the same thing happened again; there was the loud noise and it jammed.
Video showing how it jams.
This time we guessed that it might still be misaligned, or it might be instead due to the screw not filling out the entire piston head space. This would allow the connector some room to still move up and down, and might be what’s causing the jamming instead. We tried to use masking tape to fill out the hole as a temporary solution, so that the the hole would be smaller for our screw to fit perfectly and tightly.
Just as we were about to open up Fusion360 to make further revisions, Alexis took a closer look at the machinery and found scratch marks in an arch on the linear actuator. Powering it up again, the jam sound appeared to be originating from that area too. We added some Super-lube Teflon (PTFE) Synthetic Grease to the machinery, especially where it was scratched up, and now it works perfectly!!
Major Brackets Mk V
Nearing the end of the day, we decided to also modify the Major Brackets design and send it for printing. This is so that it can be better aligned for our final product.
Complete Prototype Testing #2
After mounting and lubing, we decided that it was time to finally programme our 3D Printer with Marlin (firmware). First, we downloaded U8glib library from Arduino and modified a few lines of code on Ramps 1.4 to remove the heating function on our printing bed. Afterwards, we uploaded the entire modified Marlin folder onto our open-source controller, which consists of a Ramps 1.4 shield mounted to an Arduino Mega 2560 controller. After programming, we first wired in our stepper motor to the extruder pins and with the help of an external power supply, we managed to test the function of the stepper motor. AND YES, IT WORKED! We got it rotating and our LA’s module jabbed up and down. However, we realized that the jabbing speed was really really slow. Hence, Vanessa went to switch off the power supply and manually modified the hardware of the open-source controller. She first removed one micro-step jumper pin and the rotating speed increased. However, it was only a slight increase without much significance. Thus, Vanessa went on to remove another micro-step jumper pin. AND YES! The increase in rotating speed and ultimately, the jabbing speed, was much more obvious! We were quite happy and excited but we were also hoping that it could still go faster. Hence, we decided to remove our last micro-step jumper pin and we managed to get it jabbing really really fast (almost three times the original speed of the DC motor that was initially attached to the LA). In addition, although the jabbing motion was a lot faster, the piston structure did not jam too! That was really amazing and happy for us!
With this, we finally went on to wire the remaining motors on our 3D printer to the open-source controller. Hence, firstly, we have to manually unscrew and remove the 3D printer’s controller that came with it initially. Next, we removed the wires that connect the internal power supply to our 3D printer’s controller as well as removed the relevant wires connected to the relevant motors in the 3D printer. While doing so, we realized that the length of the wire that came with the 3d printer might be too short to connect to our open-source controller comfortably. Hence, we had to use a longer wire for every motor, which Tony happened to have in the lab (YAY!). While replacing the wires, we learnt that the polarity of the wires when connected matters when getting our 3D printer to function normally. Hence, for some wires, we had to manually switch the positions to get the correct arrangement. After connecting the relevant motors to our new controller, Vanessa remembered that we also need to re-home our 3D printer due to the shape of our newly 3D-printed embroidery hoop base. In order to prevent the 3D printer from embroidering in the air, we need to re-home our 3D printer such that the entire “house” was on the left side of the circular embroidery hoop (away from the outer wooden hoop). Hence, to do so, we first had to remove the existing clicker mounted to our relevant X-axis and Y-axis motors on the 3D printers. Next, we placed the new clicker at the positions we want our home to be. To attach the new clickers onto the X-axis and Y-axis, we used hot glue and screws respectively. Hot glue was used for the X-axis because the structure of the 3D printer along the X-axis did not allow for the use of screws whereas for the Y-axis, the structure on the 3D printer allowed for it. Finally, after rewiring and re-homing our 3D printer, we powered our open-source controller with a power bank and got our printer to switch on properly! YAY! We first played along with the movement of the x-axis before deciding to test out the auto-home function. Guess what! The auto-home went wrong and the “house” started jamming as it moved in the wrong direction. We panicked a little after hearing the jamming sound but with the help of Guo Yao (a MnT lab personnel), we realized that it was due to the wrong wiring of the wires! We wired in the wires with the wrong polarity and hence, the communication with the 3D printer was affected. After switching the polarity of the wires, the auto-home worked! YAY! All the relevant motors worked perfectly! What’s left is to code for the stepper motor directly on Marlin, which is currently connected to the extruder pins to get it rotating for a few revolutions before stopping. Hence, giving time for the printer to move in the X/Y direction before the needle starts jabbing again. Thereby, minimizing the occurrences of the needle being dragged along with the fabric to reduce the amount of damage to both the needle and fabric while obtaining a more precise job.
We aim to run a test print next week with a G code generated from Cura to coordinate both the X/Y movement and the jabbing movement. From there, we hope to modify our stepper motor code successfully on Marlin for Ramps 1.4! So, stay tuned for more updates next week!! π