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AmirHAmirH Posts: 4 Apprentice
Hi there,
I am programming the UR5 dynamics. i was able to find moment inertia and mass for links but could not find the joint motor masses. Is there ant specs sheet for it? Thank you in advance

Best Answer


  • jelmsjelms Posts: 34 Handy
    The only specifications I'm aware of are here. If you need additional ones I'd reach out to UR support.
  • AmirHAmirH Posts: 4 Apprentice
    Thanks. I have used the specs you addressed, which provide link masses. However, there are motors inside UR5 joint caps that carry extra weight; and I planning to consider that in my code. Please advise. Amir
  • jelmsjelms Posts: 34 Handy
    I believe the UR specs in the link include the mass of all parts (including motors) of a unmodified arm.
  • AmirHAmirH Posts: 4 Apprentice
    edited May 2020
    So I do not need to add any weights pertaining to the motors? Is there any resource you could refer me to please? The reason why I am unsure about this is, link masses are supposed to be taken as concentrated mass at the CG of the each link which I did so in my code. It does not appear to have motor weights included.
  • jelmsjelms Posts: 34 Handy
    I think that makes sense. The 3.5kg are probably the portion of the base that doesn't move.
  • matthewd92matthewd92 Founding Pro, Tactile Sensor Beta Testers Posts: 1,267 Handy
    That makes sense, seems a little heavy but I bet it’s close. 
  • AmirHAmirH Posts: 4 Apprentice
    matthewd92jelms , thank you. I have got two more questions:
    1. I am using FT300 and TCP/IP Communication data stream socket 30003 to collect TCP force data. Data pertaining to the former ranges btw -20+20 and for the latter it ranges btw -600+600. I should say I just lay my right hand on the fixture kept by the gripper at the endeffector. That being said, outcome pertaining to FT300 makes much more sense given the Newton as the force unit. What about the data collected from socket 30003 ?

    2. Again using socket 30003 , I have collected the joint current. In order to convert that to actual torque I need the Kt associated with the UR5. How can I find the Kt?

  • jelmsjelms Posts: 34 Handy
    AmirH, I don't have any direct experience with that. You may be able to compare using a script. The values returned from get_tcp_force (see this link) for force. For per joint torque you'll need to use get_joint_torques()
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