Assembling my new servo tester

I have been getting to animatronics a lot more lately. This means I constantly have to test servos to ensure they are functioning properly and find out where their range of motion is. Particularly I need to find the center point of each servo, since that is where I usually need it positioned to fit in a 3D printed project. To that end I decided to make a servo tester based upon the design by Will Cogley.

I did try to recreate his project to begin with, but found the components I chose would not fit in his design. So I designed my own case and made some slight adjustments to the original design. The biggest changes are adding a power switch, power light, and distribution block. Here is a look at the tester being tested for the first time:

@stelanthin2

It works! Love the rush of making things! #electronicproject #animatronics #servo #arduino #3dprint

♬ Rockit – Herbie Hancock

Schematic

I didn’t create a schematic for this. I followed the schematic created by Mr Cogley and just added my changes where they seemed appropriate. If anyone wants a schematic, I can make one and post it here.

3D printed case

The case I designed is on Thangs. If you are like me and use different hardware, I would recommend designing your own case. Every time I do projects like this, I pick up some new Fusion skills.

BOM

Here are the parts I used. This seems like a long list. But most of these are items I already had in my shop and keep on hand. If you want to build this yourself, I would recommend finding versions of these parts that you either have on hand or can easily obtain. But, I do have links to purchase these from Amazon if you wish (I am an Amazon affiliate and may get commision from sales).

• 3D printed case available on Thangs.
• 1.8 Inch TFT LCD Screen Display Module. I used this one from Jessinie since I already had it on hand from another project.
• M2x8mm button head screws. 4 with a nut and set of washers for each. This is for the TFT
• 2×6 Position Terminal Block Distribution Module. I use this for power distribution throughout the project. This easily allows Dupont connections.
• M2x8mm button head screws. 4 with a nut and set of washers for each. This is for the TFT
• DC-099 5.5 mm x 2.5mm 30V 10A DC Power Jack Socket,Threaded Female Panel Mount Connector Adapter.
• 6mm 3V-4.5V-5V-6V-7.5V-9VDC LED Metal Indicator Light Waterproof Signal Lamp. This has been my recent go-to for professional looking LEDs in a project. I also put a 470 ohm resistor in this positive lead.
• Toggle Switches, 2 Pin 20A 125V AC/ 15A 250V AC ON Off Switch, SPST Car Rocker Switches with Boot Cap Cover, 12V Heavy Duty Waterproof Toggle Switch. I just like the look of these.
• B10K 10K Ohm Knurled Shaft Linear Rotary Taper Potentiometer with Black Knob. These pots have been my go-to for a while. They are good enough and look professional.
• 22 AWG stranded wire. I use this for the pots, and basically everything else in this project (except for the solid that I used on the power connector).
• PCA9685 16 Channel 12-Bit PWM Servo Motor Driver IIC Module. I really like this board from HiLetgo for projects like this.
• SPST Momentary Mini Push Button Switch Normal Open. 2 of these for the up and down buttons.
• 4 – M3x8mm Threaded Inserts for the case.
• 2 – M3x6mm Threaded Inserts for the Uno.
• Uno R3. I have had good luck with the Elegoo Uno over the years. But you can never go wrong with an original Arduino Uno.
• Dupont connectors. Shitloads of them. Some of them came with parts I made in the past. Others I made using AWG 22 stranded wire and this kit.
• 5V DC power supply. Nothing fancy for this is needed. It doesn’t get used much and won’t draw much power.

Build process

I created this TikTok showing the build process:

Thanks for coming by!

Thanks to anyone looking at my project. I had fun with this one. If anyone tries this project and runs into any issues please let me know. I am more than happy to help out as I can.