Abstract:
Hot solderings have been around for a long time. There are evidences confirming this
existing from many discoveries of jewelries and various tools made of metal with soldering dating back to more than 4,000 years ago, when various minerals began to be discovered. For the present era where various facilities rely mainly on electrical and electronic equipment. Hot soldering plays an important role in connecting various circuits together. Hand soldering is still widely popular for medium to small enterprises or SME including: repairs, rebuilds, or dismantling and reusing works. Fume emited from soldering process which consists of Lead and tin posts a potential risk of danger.
This research study aimed to design and built a collaborative robot (COBOT) with a
mechanical arm that has the ability to move the mouth of the hood in following a soldering iron that radiates heat with an IR (Infra-red) sensor.This will work in collaboration with a local ventilation system consisting of flexible duct, fans and air cleaning devince, equipped with charcoal filters, to remove fume from the hand soldering work. This will be followed by the efficiency test in terms of ventilation, electrical and fume extraction properties caused by the hand soldering process which set up at various tested locations compared to the conventional one.
After the design and build process, it released to a prototype of collaborative robots
(COBOT) with 4 degrees of fredom (DOF) robotic arm. It utilized 4 servo motors and worked under the control unit of Raspbery pi 4 which used Python language as the commanding codes and the communication with the amg8833-ir-8x8-infrared-thermal-imager-array-sensor. The efficiency test results showed that the prototype had an ability to perform its tasks according with the research objectives. It could track and follow the moving soldering iron in 2 axes at the same time including rotating around the Y axis 0 - 180 degrees and covering 90 degrees in the X- Y plane with an electricity consumption rate of 60.8 W. The system had an average wind
speed in the front of the hood at 1.47 m/s with an air flow rate of 0.01 m3 /s. The maximum distance that the hood still can suct in the smoke (Capture distance) is 25 cm, when the smoke source is below the level of the hood mouth.
The fume extraction efficiency test compared between COBOT and the conventional
one was setup for working ina relatively large working area and collecting air sampling at simulated breathing zone over the working position wich according to the NIOSH method 7301 for lead (Pb) sampling. The test results showed that COBOT was more efficient than the conventional one with statistical significance at p-value = 0.041; in both terms of considerations, consisting of weight of the fume amount and the concentration of the fume that is exposed in the breathing zone of the simulated worker. And if looking specifically at the average lead fume concentration that the workers were exposed to in this test, The value is very small for COBOT
that was only 0.003616 mg/m3 . Meanwhile, the value from the conventional one, obtained in this test, was 0.169379 mg/m3 , which exceeded the recommended maximum exposure limit at 0.05 mg/m3 specified by OSHA, NIOSH, and ACGIH. And if compare with this standatd the onventional one was 3.38 times higher, meanwhile the COBOT was 13.8 times lower than the recommended one.
From the overall study results, it highlights the effectiveness of the COBOT over the
conventional one in eliminating fume pollution emitted from hand soldering work. In addition, it increases convenience and reduces time of operation. This is especially optimal for the hand soldering work in the relatively large working area, such as a dismantling of waste electronic equipment or large workpieces that need hand soldering in many places by which the conventional one would not be designed for at the first pace.