The lift mechanism continues

Just had a look back through some star wars videos, mostly to look at R2D2 color scheme, when i spotted some footage of R2D2 climbing stairs. In there version I was looking at it was 39 minutes in the episode 2 just after Padmae and Anikin arive back at Naboo. In that short 4 second clip, we see the side legs on R2D2 extending around 100 - 200 mm to help climb the stairs., maybe the above suggestion is not so screen in accurate as I first thought.

Ray Edgley

While I am waiting on my 3D printer finish printing parts, I was thinking about the control of movements and object avoidance, it occurred to me a common problem to overcome will be steps. Has anyone ever worked out a way to negotiate stairs with the R2D2? Is it something worth considering? In the movie, R2D2 had his rocket boosters on the side of his legs, but in real life we won't be able to use that method. If the motors that move the side legs back and forward are strong and we add servos/motor to control the angle of the wheels, combined with Inertial Measurement Units (IMU) we can swing the base of the body forward while retracing the center leg to get the base of the body onto the stair, but unless the side legs can extend as well, we still won't be able to tip the body straight in order to complete the stair climb. In this case we will also need the center foot to be able to control its tilt as well. All this also has the down side of no longer being screen accurate while climbing stairs. Just some more food for thought....

Ray Edgley

That was based on the gear out on its own not connected to anything was the power input gear, that's the gear we need to spin at about 500 RPM. If you need help with the control system for it, let me know, I am quite happy to help out and have had experience driving motors with differing types of feed back systems. It is also possible to use a slightly more powerful motor at a higher RPM output and slow it down with speed control using a small Arduino if needed.

Ray Edgley

Thank you! 500 rpm on the screws right? So depending on gearing but useful, cheers.

Michael Baddeley

Just some thoughts to keep in mind as you look at motors, Based on the number of threads on your screws (and my count could be out) there is about 28 thread, so a full travel will be about 28 turns. A reasonable time for the leg to deploy in would be about 2 - 4 seconds. Based on that, a geared motor with an output of around 500 RPM should give a reasonable deploy and retract time. As for the power of the motor needed, you are in a far better position to know than I am from photos :-)

Ray Edgley

Hi Ray, unfortunately I’ve not got to the motor yet. There’s mount Points but I need to get the build finish before I try motors. I’ll share as soon as I’m sure.

Michael Baddeley

Just out of curiosity, what type of motor are you planning to use with the lift? Takes what seems like forever to get part here and was wanting to get the motor on order sooner than later. I've almost finished printing off the parts for Ring2, another couple of days and I can start on Ring3. I must say your design has been easy to print so far and easy to assemble as well. Very well designed.

Ray Edgley

Awesome design, how tall is the frame?

Looking awesome! Can’t wait to see more.