
seromo
USA
Asked
— Edited
Hello, I want to make JD's legs and arms with 3 or 4 servo each. Has any one try making JD with Longer arms and legs, I'm wondering also how JD will move with more servos ? Please HELP Thank you.
There are extenders in the store for this. From the question and how it is asked, I am not going to recommend that you make cables. I would buy the extenders.
http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?prevCat=9&productNumber=8
Alan
I seriously doubt that what he is trying to do will work. servos have a certain strength and the further you get from the servo, the higher the strength that is needed. When you add in the weight of the servos along with the distance that the servos are from one another, I am pretty sure that you would ultimately come to the point that the robot wouldn't be able to move its upper servo, and thus not be able to move its leg forward or backward. He may have some design that he isn't sharing but I suspect that he will run into issues.
Alan
Instead of using Jd, I used some of the .stl files from "Poppy". I found them to be light and strong. I installed regular servos in place of the Dynamixel servos normally used. I only moved the arms and shoulders and I also had 2 waist servos. It kind of worked but I found the servos to be weak. The spine was not real rigid, but it could hold itself up. (Waist, shoulders, arms and neck) The whole assembly really needed a lot of torque. I don't think you could ever make the whole thing really stand or walk.
Poppy was made for poses, not real standing and movement. I may go back to it to see if I can do more with arm and torso movement someday. Maybe legs too.
If you want the servo conversion tray info and on how I made the pivots let me know. I will dig around and see if I can locate pictures and .stl files
Ron R
The key to JD and EZ robots in general, is the ability to modify and try things. You have an idea which should be tried. My advice is to realize that JD has a certain amount of power in the servos. Also his balance is maintained by big feet.
I think you should build his legs first but consider his feet may need to have light weight shoes to help maintain balance. You could remove the arms for now and use those servos for tests. later you may need arms to help maintain balance.
The Auto Position panel can give you the ability to set movement. Making small movements at a time will allow you to see if he can walk the way you want.
Try making it work and post your progress.
Ron R
But, Remember, a lot of additional weight is not good.