Sunday, March 12, 2017

New Miniservo 6DOF platform that is easy to replicate

UPDATED CONTENT... (June 2017)

I wanted to make a better mini 6DOF testing platform for checking the motion software output on my desk and I since I had 3D printer I though to make a 3D printed one. I started to design one but with my limited time was taking forever. Luckily I stumbled upon this design from EraseGray:

It's complicate print (took me 3 days to finish) but the result is great and accurate. I printed the base and platform with 0.3mm layer height as I didn't need much detail on them.

The actuators were build in 0.2mm height with supports for the rod part as I wanted it laying down flat to be strong and have less ripples on its surface.

What took almost two days to print was the ball joints! I printed them with 0.1mm layer height and very slow speed (20mm/s) to have smooth surface and have accurate dimensions so they will fit together without seizing. I had to print them one by one piece (not all in the same plate) as I didn't use any retraction for the extruder to have smooth surfaces and walls.

I used 9g servos with metal gears that I found on ebay very cheap ($14 for 4 of them) (search for "4x 9g MG90S Metal Gear Micro Servo High Speed " on ebay).

Using this chance I decided to also investigate the use of Micro Maestro servo controller from pololu that some have been purchasing instead of the Micro Mini servo controller. Turns out it can be used same way if you use an offset value for the servos to match the 8 servos that the Micro Mini servo controller has.

See the video for instructions how this is done:

Photos of the platform:


And settings for the Micro Maestro servo controller:


The best thing with the Micro Maestro servo controller is you can adjust the acceleration and speed settings of the servos, to simulate accurate the response of the Full Scale 6DOF platform. Just check the acceleration and speed data from the big motors and apply them on the model to see how it will move!


San Diego, California, March 2017

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