Wednesday, December 21, 2011

Maxwell (Finally) Gets a Vertical Arm Lift

I've been saying for quite some time that I wanted to add a vertical lift to Maxwell. Earlier this month, he finally got that lift:

The linear actuator gives the arm 20" of additional vertical mobility, making it possible to grab objects at floor or table height, or hit most light switches. The lift is currently integrated into ROS arm_navigation, I'll have some awesome videos soon.

In addition to the arm upgrades, Maxwell recently got a new ASUS Xtion Pro Live to replace his Kinect. The ASUS device requires only USB (no 12V power) and is significantly less heavy, reducing neck and back stress (a common problem amongst aging robots). Speaking of aging robots, Maxwell turns one early next month.



  1. Excellent! I've been looking for a similar solution recently. Can you add more details? Are you using 80/20 extrusions with their UHMW linear bearings? Any binding problems? What kind of linear actuator are you using? Potentiometer feedback? I hope it's not to many questions at once :-)


  2. Paul,

    I am using the UHMW linear bearings -- but I'm using 2 on each side to give ~4" of length. There doesn't seem to be any binding issues.

    The linear actuator is a 20" mini-track style from Firgelli. I have not been able to find anyone willing to sell >12" actuators with feedback installed in small qty, so I had to hack my own feedback in. I ended up installing an optical interrupter and a small disk on the main shaft (under all that ugly white electrical tape).

  3. Could you please tell me how much does it cost for this robot? We want to build one for our research activities.