Introduction: DIY PCB Shaker (Low-Cost)
Tired of spending half an hour shaking a vat of Ferric Chloride? Build your own DIY Low-Cost PCB Shaker! It's a very cheap and simple project that only requires common materials. The machine can reduce etching time of Ferric Chloride down to 10 minutes, depending on the speed and the etchant's concentration.
PCB fabrication requires etching. Ferric chloride is a common choice of enchant. During etching, you can leave your PCB on a vat of etchant, but by doing this, etching time could reach up to an hour! You can agitate a vat to speed up the etching process down to 10-20mins. While this makes the process faster, 20 minutes of shaking while staring at a wall just annoys me on a daily basis, so I built a simple PCB Shaker to automate my etching process.
Step 1: TOOLS & MATERIALS:
- Plastic Tray Containers
- Geared Motor (12V - 131 RPM or slower)
- LM2596 DC-DC Adjustable Converter
- Power Brick (12v - 1A)
- 10K Ohm Potentiometer
- DC Jack
- SPDT Switch
- Wood/ Acrylic (20x40mm & 40x40mm)
- Nuts & Bolts (M3)
- Mini Hinge
- Popsicle Sticks
Step 2: Creating a "T" Bracket
For us to mount the upper and lower trays, we'll have to make a T-bracket for linking the hinge and both trays. Cut a piece from wood or acrylic. The measurements are as follows:
Vertical Piece: 20x40mm
Horizontal Piece (Base): 40x40mm
Next, grab your hinge and use it as a stencil for marking the cutouts for the holes. Use your drill for adding holes. Grab a bottle of superglue and add a few drops of superglue for bonding both pieces together to form the T bracket. You may use a ruler as a jig for aligning them perpendicular to each other.
Step 3: Glue the Bracket on the Upper Tray
The upper tray is designed to hold the etchant. As much as possible, I tried to avoid drilling holes to the upper tray for preventing the enchant from leaking. Screws also are not an option as the etchant would eventually dissolve them. You can use superglue instead for mounting your assembled T bracket at the bottom center of your tray.
Step 4: Adding a Hinge to the Lower Tray
Grab your other tray, will be using it as our lower tray. Place your hinge at the center and use the hinge as a stencil for drilling holes. Grab a pair of nuts and bolts and screw the hinge in place.
Step 5: Join Both Trays
Grab another pair of nuts and bolts, then screw both trays together. You now have a simple rocking mechanism (seesaw).
Step 6: Mounting the Gear Motor
The gear motor must be mounted at one of the sides of the lower tray. Mirror your gear motor's shaft and screw dimensions to your tray, then drill more holes.
Step 7: Adding the External Components
You can use a Dremel girding disk or a drill bit for cutting (routing) through the plastic enclosure. Mount the Switches, the DC Jack and the Potentiometer. You may add a plastic knob handle for the potentiometer to make your project look nicer.
Step 8: Removing the Regulator's Trimmer Resistor
In this project, I'm using a LM2596 DC-DC Buck converter for controlling the motor's speed. Apparently, the regulator's output voltage can only be controlled by tuning the trimmer resistor using a screw driver. I desoldered the trimmer resistor as I plan to replace it with a more accessible potentiometer.
Step 9: Mount the Regulator Inside the Lower Tray
I went cheap with the regulator mounts. Eventually, I just added a few drops of superglue on the two capacitors and mounted the regulator on the tray.
Step 10: Wire Them Up!
Here's a simple wiring diagram for the motor speed controller.
Step 11: Finding a Suitable Flywheel
In order to translate the gear motor's angular motion to the rocker, you'll need a flywheel and an armature. I ended up using a plastic lid from an old jar of sandwich spread. As for the armature, I used a piece of Popsicle stick. Now drill a hole on one of the ends of the popsicle stick.
Step 12: Assembling the Flywheel & Armature
Grab your improvised flywheel and drill a hole 10mm from the center. Get a bolt, add a washer then slide in your improvised armature, then screw in a nut halfway on the bolt. Fasten the Bolt-Washer-Armature to your flywheel. Use a nut to lock it in place.
Step 13: Improvised D-Shaft Mount
You may use a 3D printer to make a 4mm D-Shaft mount, for those who doesn't have access to one, you can use clay epoxy for mounting the flywheel to the gear motor's shaft. Make sure, both of them are aligned properly as the epoxy sets.
Tip: Sand the flywheel's plastic surface, for the epoxy to bond with the plastic.
Step 14: Adding a Pin
You can add a pin for the armature, by drilling a hole on the upper tray. Use a nut, washer and bolt to make this.
Step 15: Balancing (Quick Test)
Find a suitable power brick for your project. Since my gear motor is rated at 12V, I used a 12V powerbrick for powering it. You'll have to turn on the machine on this step as you will have to attempt to balance it.
Your rocker may either lean extremely to the left or to the right. Balancing the rocker requires patience. Here's the only thing you need to know, it all boils down to the armature length. You can conduct trial and error as you drill holes to find the perfect balance.
Step 16: Trim the Arm
Once you have found the perfect armature length, remove the armature from the pin. You can use a wire cutter for cutting the excess piece from the popsicle. Once done, lock the armature back to the pin. You add washers and a nut to lock it in place, perhaps add a few drops of thread locker.
Step 17: Enjoy!
Turn on your machine by flicking the power switch then turn the knob to set the rocking speed. Now you have your own PCB shaker. I hope this project helps!
Check Out My Other PCB Related Video Tutorials!