Easy Animatronic Build and Programming
by Halstaff in Circuits > Robots
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Easy Animatronic Build and Programming
Building your own Animatronic character from scratch can seem to be an overwhelming proposition. Selecting the proper materials, fabricating parts and figuring out how to program it can make this project seem out of reach for many.
I'm here to tell you that this is no longer the case. I have been taking advantage of a couple of new product lines to streamline the process. We'll be using the goBILDA products for this project. Assembly only requires a hex wrench and a screwdriver! No more spending days in the workshop cutting, drilling and bending parts to fit my design!
The programming can be the greatest roadblock for many builders . The time required learning to actually control your mechanical creation has stopped many projects from being completed.
In order to address this problem, I worked with the fine folks at Addicore. We met at a local Maker's meeting and soon decided to work together to create a new and easier way to program props. It may appear to simply be a conventional RC transmitter and controller but it is so much more! Read on to discover its secrets!
Gathering Materials
This was my first project using the goBILDA components so I ordered a few extra parts. I've used the Actobotics system from ServoCity so I am familiar with the design process but they each line has its own idiosyncrasies. Both systems are modular and offer precisely machined parts. The goBILDA parts are metric and they are larger. It is a newer product line so there are not as many parts to choose from but the library is constantly growing.
In order to create the shoulder mechanism, I did need to make the L bracket that connects the shoulder servos together as they don't currently make that part. I used 3"x3" aluminum that I cut and drilled to fit.
Here's the list of parts I ultimately used to create the basic body structure minus the wing prototype mechanism on the character's back.
goBILDA torso parts list
2 - 1109 Series goRAIL (288mm Length) SKU: 1109-0024-0288
2 - 1137 Series Steel Flat Grid Bracket (1-1) - 2 Pack SKU: 1137-0001-0001
1 - 1109 Series goRAIL (96mm Length) SKU: 1109-0024-0096
1 - 1120 Series U-Channel (9 Hole, 240mm Length) SKU: 1120-0009-0240
3 - 3206 Series Servo Gearbox (5:1 Ratio, Hitec HS-788HB Servo) SKU: 3206-0002-0005
1 - 3206 Series Servo Gearbox (7:1 Ratio, Hitec HS-788HB Servo) SKU: 3206-0002-0007
1 - 3206 Series Servo Gearbox (9:1 Ratio, Hitec HS-788HB Servo) SKU: 3206-0002-0009
2 - 1111 Series Angle Pattern Bracket (4-1) SKU: 1111-0004-0001
2 - 4103 Series goTUBE (192mm Length) SKU: 4103-0032-0192
1 - 1305 Series Thru-Hole Clamping Hub (32mm Bore) SKU: 1305-0032-0032
1 – 1126 Series Steel Flat Bracket – SKU 1126-0001-0001
1 - 2805 Series Zinc-Plated Steel goRAIL Nut (4-8) - 4 Pack SKU: 2805-0004-0008
1 – 1502 Series 4mm ID Spacer – SKU 1502-0006-0080
1 – 2800 Series Zinc-Plated Steel Socket Screw 16mm – SKU 2802-0004
1 – 1120 Series U-channel 15 hole – SKU 1120-0015-0384
2 - 2805 Series Zinc-Plated Steel goRAIL Nut (4-8) - 4 Pack SKU: 2805-0004-0008
1 - 1201 Series Quad Block Pattern Mount - SKU - 1201-0043-0002
2 – 2800 Series Zinc-Plated Steel Socket Screw 9mm – SKU 2800-0004-0009
1 - 2800 Series Zinc-Plated Steel Socket Head Screw (M4 x 0.7mm, 6mm Length) SKU: 2800-0004-0006
We will discuss further the DIY RC Controller Kit that was used to program the character but you can find it on Addicore's site at https://bit.ly/2UPMP84
You'll also want to secure a couple of 6V, 5A power supplies - https://amzn.to/2DzfQzd You can run the controller off a single power supply but it is recommended that you use the added power input headers to supply the servos with their own supply.
The board includes both a high and a low trigger input. I usually use either a PIR (passive infrared) sensor - https://bit.ly/2RlI5VG on the high trigger or a wireless relay trigger on the low trigger - https://amzn.to/3iMKRQa
You'll probably want to add some servo cable extensions to your order as the cables that come on the servos aren't long enough to reach the controller board. Here's a link to some 300mm (a little less than 12 inches) but you can find longer ones if you need them - https://amzn.to/3gSsCau
Some of these links are affiliate links. As an Amazon Associate I earn from qualifying purchases.
Putting It All Together
The assembly of the torso is a simple process. Since the bolt patterns of all the parts are identical, they line up perfectly and go together quickly. You can easily modify this design to fit your requirements.
The body utilizes 5 of the servo gearboxes which provide all the torque I need. When purchasing your gearboxes, you can choose from several different gear ratios. Since I prefer slower and smoother movement, I go with the the higher ratios. An added benefit is that the higher the gear ratio, the greater the torque. I usually use the 5:1 or 7:1 models.
I use 2 gearboxes for each shoulder mechanism. Another gearbox is placed at the bottom of the torso which allows the body to rotate back and forth.
When hooking up the servos to the recorder board, I use one joystick for each shoulder. The body rotation servo is controlled by one of the slide switches.
In the basic torso construction, I simply glued a magnet to a foam skull. The skull then attached itself to a Quad Block Pattern Mount that was installed in the center of the main shoulder U channel.
I also added a wooden plate between the 2 uprights as a mounting point for the receiver/recorder board.
Bringing Him to Life
My original idea for the controller system was to have a kit that would be included in my next DIY Animatronics book. I plan on including a chapter on soldering and I wanted a project that builders would find useful. Once I teamed up with Addicore, it morphed into something much better! You can still buy it in kit form but if that's not your thing, they are happy to assemble and test the controller for only $20.
The original receiver board allows for live puppeteering of up to four props by simply changing the switch settings. Addicore has a several videos on their site that will walk you through the process of setting up your transmitter if this is an option you'd like to use.
However the true beauty of this system is the new recorder board which allows you to record your animation sequence separately unto 4 separate tracks that can be recorded independently but played back simultaneously. Once your satisfied with your routine, the receiver can then be used as an inexpensive, stand alone, triggerable prop and Animatronic controller! The transmitter is now available to program another recorder board!
The system utilizes an SD card to store your routine as well as an easy to adapt text file which allows you to easily adjust settings such as the servo limits, servo direction, retrigger delays and more. The addition of the digital pins allows you to trigger other boards, run LED's or control relays. This makes for an extremely functional arrangement that lets you personalize it to fit your needs.
The code is open source and tweaking it to fit your needs is encouraged.
What to Do Next
The system was designed to allow you to expand it and use additional controllers. For a more advanced character, I added a 3 axis skull with servo driven eyes that move back and forth. These servos are controller by a second DIY Recorder Board that is triggered when I start the primary programming of the torso. I connect the trigger wire from the secondary recorder to one of the digital button outputs on the primary recorder board. The audio is provided by a Wee Little Talker from Haunt Hackers which syncs the speaking track to the jaw movements. This board is triggered in the same manner as the secondary recorder board - http://www.haunthackers.com/weelittletalker/index.shtml
My prototype wing mechanism uses a linear servo from Actuonix. These actuators are an easy way to apply lateral motion instead of the rotary motion that servos provide. They provide more torque than a servo but they are slower. Perfect for my application! https://www.actuonix.com/
The completed mechanism will of course still need to have a body form of some sort installed and be dressed. If you'd like to see my process for putting together a foam body for my props, check out this video.
This system is still in its infancy with more cool features to be added soon. Stay tuned for those updates by joining the Addicore forum at https://forum.boffintronics.com/
I hope that this process will encourage you to try your hand at building your own Animatronic character. Seeing a figure that you built come alive and entertain others is extremely gratifying!