Following the last publication about PCB (printed circuit board) manufacture, we present another useful project. The corrosion with iron perchloride, is a slow speed process, but we can accelerate the process, by agitating regularly the solution. To do this, we created a simple device, able to make an automatic PCB agitator, using an old DVD desktop drive.
First it’s necessary to disassemble the drive removing the electronics and all the mechanisms, except the ones we see in the image below. You should just leave the laser support, his axles, and the CD’s motor.
Using a small screw, join the copper wire and the cog. The wire should have a free movement, to transmit motion to the cog. Use the same process in the other end of the wire, but screw it to the laser’s support. The cog’s screw should be closest to the center, to gain more torque and movement be shorter, otherwise the motor may not have sufficient torque to move.
To support the container’s base, it was necessary to put a screw in laser’s support. Since this drive already has a hole, we just put an M8 screw. To hold the screw, we use two nuts, one for tightening the bracket and the other to create the spacing for the drive’s cover.
At this point, it’s convenient to see the screw’s movement caused by the cog, and make a cut in the drive´s cover, with the appropriate size so that can move to the rear and to the front.
To make the container’s base, we use acrylic, because we have a lot available. We cut the acrylic, at container’s size, and did a hole for the bolt which is in the laser’s support. The base of the container should not be greater than the drive, because the motor is not strong enough for large containers.
Finally, we connect a transformer to the motor, 3V or 5V, depending on the desired speed, and put together all parts, which looked like this:
Here is a test run:
This project can be improved by decreasing the motor’s speed and increasing the base movement. However, with this motor, that was not possible. Lowering the voltage to decrease speed will also decrease torque and the engine wont be able to start.