Results 1 to 5 of 5

Thread: Printy The Mech

  1. #1
    Join Date
    Jul 2012
    Location
    Richmond, IN
    Posts
    652
    Rep Power
    37

    Printy The Mech

    So, just got myself a 3d printer and decided to have another go at a mech.

    Here's some teaser pics of the new legs:

    Click image for larger version. 

Name:	NewlegRender1.jpg 
Views:	142 
Size:	17.7 KB 
ID:	7481

    Click image for larger version. 

Name:	NewlegRender2.jpg 
Views:	135 
Size:	16.2 KB 
ID:	7482


    These are renders, as I'm waiting for the 20+ hr printing process for each tibia.

    Yeah, a MP Select Mini isn't very fast. (But it's cheap!)

    Will update as I get more done.

  2. #2
    Join Date
    Jun 2011
    Location
    USA
    Posts
    533
    Images
    107
    Rep Power
    39

    Re: Printy The Mech

    Great to see you still have the itch! For the sake of your servos, I would suggest you do some torque calculations to see the loads on your servos with that leg design.

    The key number is going to be to minimize the torque around the first servo (femur servo?) after the coax. The peak static torque is going to be (assuming you walk with two legs off the ground at a time) roughly half your mech weight times the distance between the servo's axis and the contact patch (e.g. 66.67 mm in the sketch below). If I want my legs' feet further out from the robot, my best bet will be to increase the distance between coax servo and the femur servo (52 mm below).

    As a comparison point, see the compact leg geometry of my in-progress mech:
    Click image for larger version. 

Name:	numa2_leg_geom_sketch.jpg 
Views:	68 
Size:	29.5 KB 
ID:	7483

    While it doesn't reduce the key distance much compared with my first mech, it does reduce the weight of the legs by a servo, and lowers the body height (stability)...
    Click image for larger version. 

Name:	Numa1.jpg 
Views:	69 
Size:	46.1 KB 
ID:	7484

  3. #3
    Join Date
    Jul 2012
    Location
    Richmond, IN
    Posts
    652
    Rep Power
    37

    Re: Printy The Mech

    The intent is to have the femurs sit with the tibia servo flat to the ground, which will adjust the loading angle on the servo you mention to be more of an inline pull and less of a twisting torque. Also to lower the body to adjust for the roughly 180mm long tibias.

  4. #4
    Join Date
    Sep 2010
    Posts
    198
    Images
    16
    Rep Power
    36

    Re: Printy The Mech

    Cool, I recently have enjoyed the fun of 3d printing a new mech. So much easier then cutting stuff by hand! Looking forward to seeing it develop.

  5. #5
    Join Date
    Jul 2012
    Location
    Richmond, IN
    Posts
    652
    Rep Power
    37

    Re: Printy The Mech

    Well guys. I'm at an impasse. Do I print it in the bright blue, coffee, or yellow gold PLA? Thinking a mix of coffee and gold, but not quite sure.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •