Sunday, August 5, 2018

Robot Fail Week!

Nobody said inventing would be easy!

Go home robot, you're drunk!

This week has been mostly errors in the 'trial and error' school of invention.  But, alas! that is part of the process.

Mojo did get a new chassis and spent some time moving the components from the previous version to the upgrade.  Important features include:
  • additional separation of the knee and hip servos
  • roll bars and front/rear bumpers
  • more room for wiring and 9V battery
  • "learnings" from the previous design/print - 7cm spans worked with better design
  • room for future proto board, LEDs, Buttons, and Switches
He is a bit longer, I had some concern about effects to the gait.  but, the servo separation will allow for longer gaits.

Mojo - New Chassis, improved SEA, same Compliant Quadruped
Currently, It is still going through variations on the gait sequence.  The new Lateral Sequence is promising. I increased the gait length and speed up the swing, however this is had a negative impact to stability. I will need to rework the gait, but I think the fast swing is important. Might also be worth trying a very very slow gait to start.

Smokin' Servos!

The Fail of the Week was the secret "Lizard" project. I was kicking around ideas about a very basic crawler, something with two 'legs' that moved and drags the bot along. it would have just 2 degrees of freedom. In addition I added a pincher to the front, just because it was around. the pincher, takes away from the Lizard motif, but its cool.

Cool or not, I worked on a Minimal Viable 'Prototype', with servos stuck together and reused the old mojo chassis. I wried up a 5v, 2A power bank, a Arduino Pro Mini and the servos. A few lines of Arduino sketch, and I thought I was ready to go. Unfortunately, I got no movement from the servos. I checked the wiring, all good, code up loading, check, code running, check. Odd smell? check! When I picked up the bot, I noticed that the servos were 'Fire Dog Hot' and smelling cooked!  I am pretty sure they are toast now.  This I did not expect. Everything was 'safe', more debugging needed!!

Fail Lizard!

Back to the drawing board for the 'Fail Lizard' - might as well make it a new beasty!
The down side of mechatronics, is that you typically burn out boards, servos, and sensors - in addition to hanging code.  Fail Lizard brings my servo bone pile up to 5 servos!

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