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Spring 2016 3D SMD: Reel Feeder Bracket

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By Nasser Alsharafi (Manufacturing)

Table of Contents

The Reel Feeder

The Reel Feeder shown above is a major component of the pick and place machine. This component is fully automated, and has custom fabricated aluminum parts. It is made up an aluminum base, four SMD part reels, four servos, four legs, and one axle, 4 spacer drums.

The base has four cut channels that are 8mm wide. There are four reels that are positioned on an axle that spins freely. This forces the component tape in the reels to be channeled through the 8mm grooves. There are additional legs that are bolted to the base that hold the axle and the SMD part reels.

The Base

The base is (10.0 inches long   x 4.0 inches wide) the base has four channeled grooves spaced by 8mm across. The base has a tape guard that spans the entire width this is to ensure that the tape stays in the grooved channel.

 

The Reels

The four reels made of plastic that are positioned on an axle that spins freely. The reels spin and dispense the parts onto the aluminum table. The part reels are 5 inches in diameter. Two 5-inch long legs bolt into the base hold up the reels and axle. The reels hold SMD component tape. A plastic cover seals the tape. The size of the components in the SMD tape are very small at 0402.

The Custom Servo Platform

The four servos are mounted onto an adjustable platform by 8 screws. There are four spools attached to the servo, which contain the tape as it wraps up the plastic. The platform is set at 45 degrees from the base. This allows the plastic cover to be pulled off the SMD part tape, and advances the tape simultaneously. The device has legs for the custom bracket that are mounted by 2 screws to the base. The custom servo platform is fabricated from a rectangular piece of aluminum. The servos placed in a 0.9 inch cut out section of the aluminum are evenly spaced out the entire length of the 4.0-inch platform.

Screen Shot 2016-04-19 at 10.25.45 AM

Spring 2016 3D SMD: Z-Axis Beam

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By Henry Nguyen (Electronics and Control)

Table of Contents

Introduction

When running our accuracy tests, I found that the current beam on our Z-Axis would wobble. After carefully observing the wobbling, I found that this will be a major problem when we needed to assemble a PCB with surface mount components. The wobbling will cause our machine to be very inaccurate and may cause us to fail our machine.

Old Beam

Figure 1. Old Beam

Figure 1. Old Beam

Not only was our old beam wobbling because the holes where the 4mm rod went through were slightly larger than 4mm. This will cause the beam to lean forward due to the weight of our A-axis stepper motor. Now that the beam is being tilt forward, our Z-Axis stepper motor will sometime stall out because of the friction against the 4mm rod and the thread beam.

New Beam

Figure 2. Beam Measurements

Figure 2. New Beam Measurements

For our new beam, I decided to make it approximately 0.754 inches. This meant that our beam will be longer than our older beam. I believed by extending the length, we will be able to prevent the wobbling caused by the two rods. The middle hole shown in the figure above will be tapped for our thread screw. The two holes in the middle is to attached our A-Axis stepper motor bracket.

Figure 3. Z-Axis Beam Manufactured

Figure 3: Z-Axis Beam Manufactured.

I was able to get Z-Axis beam manufactured. I found that after installing this bracket, we were able to solve the problem of our Z-Axis stepper motor stalling due to the proper size hole that the rod is now able to go through perfectly.

Figure 4. Lubricant

Figure 4. Lubricant

It was also important to apply some CRC Heavy Duty Silicone lubricant onto the beam and the thread screw to allow smooth vertical movement of our new beam. The following link is a video of our new beam in action.

https://youtu.be/214bttIEprQ

Conclusion

It was very important to manufacture a new beam for our Z-Axis. Before we would have a lot of error caused by the Makeblock beam that came with our thread drive kit. The old beam would wobble a lot which is a major problem when we are trying to be as accurate as possible. Other times, the poorly manufactured beam would also cause our z-axis stepper motor to stall because it did not move up and down smoothly. By manufacturing this new beam we are able to increase our accuracy of our machine.