When: 17 June 2019, 1pm
Members present: Carissa and Vanessa
Today, we deconstructed the nozzle head of our 3D printer to make space for our needle! There are 2 ways to attach our needle: (1) Attach it directly to a tube, which is connected to the head of the linear actuator OR (2) Attach it to an inner tubing within the external tube and connect the inner tubing to the head of the linear actuator.
2 ways to attach our needleWe tried out both ways today. For the first method, we used masking tape to tape the external tubing to the head of the linear actuator. Next, we 3D printed an external support (pink cuboid with an open cylinder in the middle) for our tubing to pass through. This external support was then taped to the region previously occupies by the nozzle. The tube was eventually inserted through the external support to keep the bottom part of the tube vertical. With this, we taped our needle to the end of the tube, which should be kept vertical by the support, so that our needle can jab up and down vertically. However, after 3D printing out our external structure, we realised that the 3D printed external support could just exactly fit the tube. It was quite tight and restricted the movement of our tube. Also, the external structure failed to keep our tube vertical. Hence, our attached needle was not vertical too and was unable to penetrate through the yarn to make a stitch. Hence, we decided that maybe the first method was not that feasible.
Next, we moved on to trying out the second method where we first inserted the inner tube into the external tube. Next, we used masking tape to tape the internal tube to the head of the linear actuator. Afterwards, we used masking tape to tape our needle to the other end of the inner tubing. Lastly, we used masking tape to tape our external tube to the region previously occupied by the nozzle to act as a temporary clamp to hold the external tube in place. When we use our hands instead of the linear actuator to manually induce the up-and-down movement using this method, the method worked. However, when we powered our linear actuator, we discovered a few difficulties and decided to study the mechanism for this transfer in “jabbing” motion by removing the needle. This way, we could use just the linear actuator and tubes to better understand the transfer mechanism. Some findings that we obtained are listed below:
- It was difficult to hold the linear actuator in place as it wobbled quite a bit without a clamp. This affected the movement of the inner tube and eventually, our needle movement too.
- We discovered that one clamping point for our external tube was not enough. We needed at least 2 clamping points – one near the linear actuator and the other one near the needle.
- The speed of the linear actuator was too slow and hence, we need to replace the DC motor with a stepper motor.
- The tubes that we were using might be too short for our printer. The length of the tubes (distance from the linear actuator to the extreme end of the printer) must be sufficient such that they can reach the extreme ends of the embroidery hoop.
- The 3D printed yarn/thread feeder (as seen in post [#10]) was not sturdy enough to hold its weight against the fabric. Hence, when the needle was jabbing, the yarn feeder lifted off the fabric. This made it difficult for the needle to come into direct contact with the yarn and securely form a stitch in the cloth.
Moving on, we need to first figure out the optimum distance and position of our linear actuator and measure the distance from the linear actuator to the extreme end of the embroidery hoop to get the correct length for the tubes. Secondly, we need to figure out the clamping positions and distances as well as the method of clamping for both the linear actuator and the external tubing. Thirdly, we need to improve our 3D printed yarn feeder by either changing the material of the feeder to a heavier weight material or increase the material in the base of our feeder. Lastly, we need to replace our 3D printer controller with an open-source controller, and edit the firmware (Marlin) to fit our application. With this open-source controller, we can then use the extruder stepper motor (not used at all for our 2D embroidery machine) to replace the DC motor of our linear actuator and code using Arduino to increase the rotation speed of our stepper motor and eventually, the jabbing speed of our linear actuator. With all these done, what’s left will be to try out and coordinate the different speed of x,y movement and vertical jabbing movement for precision purposes. 🙂