HexPi - A RoboPi + Raspberry Pi based hexapod robot

My first hexapod build!

I've been itching to build one for a long time now, but the cost of the very nice Lynxmotion kit was out of my toy budget.

After scouring Ebay, I found an inexpensive chassis (search for "hexapod" on Ebay), and inexpensive - yet reasonably high torque servos (Tower Pro MG995, they get poor reviews, but are inexpensive, and not as bad as some reviews make them out to be).

You can find my full build log with a lot more details at:

http://www.mikronauts.com/robot-zoo/hexpi-hexapod-pi-robot/

This is a mini-version right here on Let's Make Robots.

May 30, 2014

I think I have the servo jitter under control, I am working on running multiple legs at once with my servo tester. Stay tuned!

Here are a couple of shots to whet your appetite:

(HexPi chassis complete, "shoulders/hips" calibrated)

HexPi showing off his calibrated, attached legs

(HexPi showing off his attached, calibrated legs)

I'll add photos at major milestones here, more details in the build log at the link above.

My next task is to set up the motor and RoboPi power systems, add a RoboPi, set up all the servos on it, and start working on gaits... then inverse kinematics.

June 11, 2014

Added a video to my build log, showing HexPi wiggling his legs. It also unforunately demonstrates the jitter issue with the TowerPro MG-995 servos.

June 18, 2014

HexPi got three pairs of new shoes!!!

Ok, the real update is that I added 50cm servo extension cables to better be able to test HexPi's legs, and while at it I cleaned up the wiring.

HexPi @Mikronauts http://Mikronauts.com

More photos and build details in the full build log:

http://www.mikronauts.com/robot-zoo/hexpi-hexapod-pi-robot/

I'd love to hear about your experiences building hexapods!

Links:

https://www.robotshop.com/letsmakerobots/robopi-most-powerful-robot-controller-raspberry-pi-adds-8-core-co-processor

http://www.mikronauts.com/raspberry-pi/robopi/

http://www.ebay.com/itm/Arduino-Aluminium-Hexapod-Spider-Six-3DOF-Legs-Robot-Frame-Kit-ge-/251195993457

http://www.ebay.com/itm/MG995-High-Speed-Digital-Metal-Gear-2BB-Torque-RC-for-Servo-HPI-Savage-XL-FUTABA-/310700893798


This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/hexpi-a-robopi-raspberry-pi-based-hexapod-robot

This is pretty cool for

This is pretty cool for something that will make me scream "eeeeek!"

Spiders scare me, but this aluminum guy is kinda neat… I hope when done he has some cute face so I’m not scared!

Thank you

LOL!

I got the brushed aluminum on purpose… I did not want my nephews and niece to run away screatming!

HexPi will get a sensor cluster (ok, fine, head) after I get the low level  control working well :slight_smile:

Video coming soon…

I test-wiggled each leg today with my “The Better Mousetrap Servo Tester” and it is looking like roughly 1/3rd of the servos still have jitter issues when I have 3000uF worth of electrolytic capacitors filtering the power. As soon as I pick up some bigger capacitors, I’ll increase the filtering :slight_smile:

Worst case - I’ll have to pick the 18 “best” MG-995’s for HexPi.

I am hoping to take some video tomorrow to show the legs wiggling.